[Federal Register Volume 67, Number 235 (Friday, December 6, 2002)]
[Rules and Regulations]
[Pages 72726-72766]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-30111]



[[Page 72725]]

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Part II





Department of Transporation





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Federal Aviation Administration



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14 CFR Parts 119 et al.



Aging Airplane Safety; Final Rule and Notices

  Federal Register / Vol. 67, No. 235 / Friday, December 6, 2002 / 
Rules and Regulations  

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 119, 121, 129, 135, and 183

[Docket No. FAA-1999-5401; Amdt. Nos. 119-6, 121-284, 129-34, 135-81, 
and 183-11]
RIN 2120-AE42


Aging Airplane Safety

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Interim final rule; request for comments.

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SUMMARY: This final rule requires airplanes operated under title 14, 
Code of Federal Regulations (14 CFR) part 121, U.S.-registered 
multiengine airplanes operated under 14 CFR part 129, and multiengine 
airplanes used in scheduled operations under 14 CFR part 135 to undergo 
inspections and records reviews by the Administrator or a designated 
representative after their 14th year in service and at specified 
intervals thereafter. These inspections and records reviews will ensure 
that the maintenance of these airplanes' age-sensitive parts and 
components has been adequate and timely.
    The final rule also prohibits operation of these airplanes after 
specified deadlines unless damage-tolerance-based inspections and 
procedures are included in their maintenance or inspection programs. 
Operators of airplanes initially certificated with nine or fewer 
passenger seats, however, may incorporate service-history-based 
inspections instead of damage-tolerance-based inspections and 
procedures in those airplanes' maintenance or inspection programs. This 
final rule does not apply to airplanes operated between any point 
within the State of Alaska and any other point within the State of 
Alaska.
    This rule represents a critical step toward compliance with the 
Aging Aircraft Safety Act of 1991 and helps to ensure the continuing 
airworthiness of aging airplanes operating in scheduled service.

DATES: This interim final rule is effective December 8, 2003. Comments 
must be received on or before February 4, 2003.

ADDRESSES: Address your comments to the Docket Management System, U.S. 
Department of Transportation, Room Plaza 401, 400 Seventh Street, SW., 
Washington, DC 20590-0001. You must identify the docket number FAA-
1999-5401 at the beginning of your comments, and you should submit two 
copies of your comments. If you wish to receive confirmation that FAA 
received your comments, include a self-addressed, stamped postcard.
    You may also submit comments through the Internet to http://dms.dot.gov. You may review the public docket containing comments to 
this interim final rule in person in the Dockets Office between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays. The Dockets 
Office is on the plaza level of the Nassif Building at the Department 
of Transportation at the above address. Also, you may review public 
dockets on the Internet at http://dms.dot.gov.
    Comments that you may consider to be of a sensitive security nature 
should not be sent to the docket management system. Send those comments 
to the FAA, Office of Rulemaking, ARM-1, 800 Independence Avenue, SW., 
Washington, DC 20591.

FOR FURTHER INFORMATION CONTACT: Frederick Sobeck, Airplane Maintenance 
Division, AFS-304, Flight Standards Service, Federal Aviation 
Administration, 800 Independence Avenue SW., Washington, DC 20591; 
telephone (202) 267-7355; facsimile (202) 267-5115.

SUPPLEMENTARY INFORMATION:

Comments Invited

    This interim final rule is based on comments received on notice no. 
99-02 entitled ``Aging Airplane Safety. `` The final rule is 
significantly different from the proposed action due largely in 
response to the comments received. In some instances, the FAA agreed in 
total or in part with many comments. In other instances, we did not 
agree with the commenters' suggestions citing the need and providing 
further justification and rationale for certain requirements, as 
proposed.
    The FAA believes it has developed a rule that fulfills its 
regulatory responsibility to meet the requirements of the Aging 
Aircraft Safety Act, and considers the impact on those affected and the 
recommendations and alternatives received in response to comments 
received. However, the FAA continually seeks to find ways to implement 
its rules at lower cost without compromising safety. To this end, we 
solicit comments from interested parties on how implementation costs 
for this rule could be further reduced. Substantive comments should be 
accompanied by cost estimates to the extent possible. Any 
recommendations for alternatives to the final rule adopted here should 
demonstrate that the alternative would provide a level of safety 
equivalent to this rule.
    In particular, the FAA invites commenters to focus on alternatives 
posed by the Air Transport Association. For example, the ATA suggested 
that the proposal be framed as an Airworthiness Directive. As explained 
herein, the FAA does not agree that ADs should be used to implement the 
new requirements. Airworthiness Directives are used to address unsafe 
conditions that have already been identified. This rule is to ensure 
the continuing structural airworthiness of aircraft as they continue in 
service.
    Further, the ATA believes the requirements of this rule exceed the 
requirements of the Aging Aircraft Safety Act (AASA) by requiring an 
unsegmented simultaneous review of each affected airplane and its 
records. The FAA has revised the inspection requirements to enable 
operators who have segmented maintenance programs, for example, to work 
with their principal maintenance inspector to agree on which inspection 
examines the largest portion of the airplane. The operator can make the 
airplane available to the FAA during that inspection to ensure the 
inspection and records review is complied with in a comprehensive, 
efficient, and cost effective manner.
    However, an operator who uses segmented maintenance programs may 
still be required under the rule adopted here to open and make 
available for inspection additional areas of the airplane to fulfill 
the requirements of the AASA. As explained in this preamble, we believe 
that opening additional areas may be necessary to ensure adequate 
inspections. However, we are sensitive to the additional cost that 
operators may incur when opening the aircraft more than originally 
planned. Therefore, commenters are invited to revisit this issue. If an 
inspection regime can be developed that would provide an equivalent 
level of safety by limiting the amount of the aircraft opened at any 
one time, the FAA will consider revising the rule.
    The FAA appreciates the significant contributions industry and the 
public has played in developing this significant and controversial 
rulemaking action. The comments have helped considerably to ensure the 
continuing airworthiness of aging airplanes.
    The FAA has summarized in the preamble the comments received on the 
notice of proposed rulemaking along with the FAA's decision on each 
comment. Individual comments can be viewed in the docket (FAA-1999-
5401)

[[Page 72727]]

established for this rulemaking action. We invite you to provide 
additional comment on the interim final rule. We will consider all 
comments received on or before the closing date for comments. This 
final rule may be amended in light of comments received.

Availability of Rulemaking Documents

    You can get an electronic copy using the Internet by taking the 
following steps:
    (1) Go to the search function of the Department of Transportation 
(DOT)'s electronic Docket Management System (DMS) Web page (http://dms.dot.gov/search).
    (2) On the search page, type in the last four digits of the docket 
number shown at the beginning of this notice. Click on ``search.''
    (3) On the next page, which contains the docket summary information 
for the docket you selected, click on the document number for the item 
you wish to view.
    You can also get an electronic copy using the Internet through the 
FAA's Web page at http://www.faa.gov/avr/arm/nprm.cfm?nav=nprm or the 
Government Printing Office's Web page at http://www.access.gpo.gov/su_docs/aces/aces140.html.
    You can also get a copy by submitting a request to the Federal 
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence 
Avenue SW., Washington, DC 20591, or by calling (202) 267-9680. Make 
sure to identify the amendment number or docket number of this 
rulemaking.

Small Business Regulatory Enforcement Fairness Act

    The Small Business Regulatory Enforcement Fairness Act (SBREFA) of 
1996 requires the FAA to comply with small entity requests for 
information or advice about compliance with statutes and regulations 
within its jurisdiction. Therefore, any small entity that has a 
question regarding this document may contact their local FAA official, 
or the person listed under FOR FURTHER INFORMATION CONTACT. You can 
find out more about SBREFA on the Internet at our site, http://www.faa.gov/avr/arm/sbrefa.htm. For more information on SBREFA, e-mail 
us at [email protected].

Background

Statutory Requirements

    In October 1991, Congress enacted title IV of Public Law 102-143, 
the ``Aging Aircraft Safety Act of 1991'' (AASA), (subsequently 
codified as section 44717 of title 49, United States Code (49 U.S.C.)) 
to address aging aircraft concerns that arose from an accident 
involving a Boeing 737 in April 1988. That airplane experienced 
explosive decompression as a result of structural failure, after being 
subjected to a high number of pressurization cycles. Section 402 of the 
AASA instructed the Administrator to ``initiate a rulemaking proceeding 
for the purpose of issuing a rule to assure the continuing 
airworthiness of aging aircraft.'' Section 402 also required ``the 
Administrator to make such inspections and conduct such reviews of 
maintenance and other records of each aircraft used by an air carrier 
to provide air transportation as may be necessary to determine that 
such is in a safe condition and is properly maintained for operation in 
air transportation.''
    The AASA specified that these inspections and records reviews 
should be carried out ``as part of each heavy maintenance check (HMC) 
of the aircraft conducted on or after the 14th year in which the 
aircraft has been in service.'' The statute also specified that an air 
carrier must be able to demonstrate as part of the inspection ``that 
maintenance of the aircraft's structure, skin, and other age-sensitive 
parts and components have been adequate and timely enough to ensure the 
highest degree of safety.''
    The AASA further instructed the Administrator to issue a rule 
requiring that an air carrier make its aircraft available for 
inspection as may be necessary to comply with the rule.

History

    The FAA's efforts to address the safety of older airplanes is known 
collectively as the ``Aging Airplane Program.'' That program addresses 
transport category airplanes, commuter category airplanes, engines, 
maintenance, and research. Through the program, the FAA determined that 
the Airbus A300; Boeing 707, 720, 727, 737, and 747; British Aerospace 
(BAe) BAC 1-11; Fokker F-28; Lockheed L-1011; and McDonnell Douglas DC-
8, DC-9/MD-80, and DC-10 airplanes were approaching design-life goals 
established by each airplane's type certificate holder. To permit the 
continued safe operation of these airplanes the FAA adopted a policy of 
mandated structural modifications and inspections through a series of 
airworthiness directives (ADs) that address specific design 
deficiencies that could lead to airplane structural damage.
    Type certificate holders also established recommended Corrosion 
Prevention and Control Programs (CPCPs) for a number of aging transport 
category airplanes. Corrosion can progressively degrade an airplane's 
strength until its structure can no longer sustain its designed load. 
These CPCPs serve as a supplement to existing maintenance requirements.
    Additionally, the FAA (1) evaluated methodologies to assess 
airplane structural repairs, (2) revised Supplemental Structural 
Inspection Documents (SSIDs), and (3) evaluated the revised Structural 
Maintenance Program General Guidelines Document, for older airplanes.
    On April 2, 1999, the FAA issued a notice of proposed rulemaking 
(NPRM) entitled ``Aging Airplane Safety'' (64 FR 16298, notice No. 99-
02). The comment period for notice No. 99-02 closed on August 2, 1999; 
however, the FAA reopened the comment period (64 FR 45090) and that 
comment period closed on October 18, 1999. The FAA issued this NPRM 
primarily to expand the use of damage-tolerance-based supplemental 
structural inspection programs (SSIPs) to a larger proportion of the 
airplanes used in air transportation and mandate the inspections and 
records reviews required by the AASA.

Related Activity

    Based on the comments received to that NPRM and the related 
proposed advisory circulars simultaneously made available for comment, 
the FAA decided not to publish Advisory Circular (AC) 91-MA, 
``Continued Airworthiness of Older Small Transport and Commuter 
Airplanes; Establishment of Damage-Tolerance-Based Inspections and 
Procedures. However, draft AC 120-XX ``Aging Airplanes Records Reviews 
and Inspections,'' now retitled ``Aging Airplane Inspections and 
Records Reviews'' and revised to reflect the final rule, is being made 
available for additional comment. This revised draft AC will provide 
guidance pertaining to aging airplane inspections and records reviews 
to be accomplished to satisfy the requirements of the final rule 
``Aging Airplane Safety''. The FAA has issued concurrently with this 
final rule a notice of availability for draft AC 120-XX seeking 
substantive comments.
    Additionally, the FAA considers that draft AC 91-56B, ``Continuing 
Structural Integrity Program for Airplanes,'' and draft AC 91-60A, 
``The Continued Airworthiness of Older Airplanes,'' are appropriate to 
the requirements of this final rule. The FAA therefore also has issued 
concurrently with this final rule notices of availability for proposed 
AC 91-56B and AC 91-60A. The public will be

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afforded the opportunity to comment on the revisions contained in these 
proposed ACs.
    The FAA revised AC 91-56A, ``Continuing Structural Integrity 
Program for Large Transport Category Airplanes,'' to AC 91-56B, 
``Continuing Structural Integrity Program for Airplanes.'' This revised 
AC will provide guidance for operators of the airplanes affected by 
this final rule on how to incorporate an FAA-approved Aging Aircraft 
Program into their FAA-approved maintenance or inspection program.
    Traditionally, AC 91-56 and AC 91-56A have provided guidance to 
operators of large transport category airplanes on how to develop a 
damage-tolerance-based SSIP, which was contained in appendix 1 to the 
AC. The FAA determined that the guidance provided in appendix 1 to AC 
91-56A is applicable to small transport category airplanes as well as 
to large transport category airplanes.
AC 91-56B
    Advisory Circular 91-56 and AC 91-56A only considered the effects 
of repairs and modifications approved by the type certificate holder, 
and the effects of repairs and modifications performed by operators on 
individual airplanes. Appendix 1 to AC 91-56B has been expanded to take 
into consideration the effect of all major repairs, major alterations, 
and modifications approved by the type certificate holder.
    In addition, proposed appendix 1 to AC 91-56B includes an expanded 
discussion on repairs, alterations, and modifications to take into 
consideration all major repairs and operator-approved alterations and 
modifications on individual airplanes.
    AC 91-56B also gives a brief description of the current Mandatory 
Modifications Program, CPCP, and Repair Assessment Program. The AC also 
states that the ``Evaluation for Widespread Fatigue Damage'' will be 
the subject of a future rulemaking activity.
AC 91-60A
    Like AC 91-56A, AC 91-60 provides guidance for operators of the 
airplanes affected by this final rule on how to develop a service-
history-based maintenance or inspection program. AC 91-60 has been 
updated in AC 91-60A to reflect current maintenance and inspection 
practices and to be consistent with the acceptable methods of 
compliance for this final rule.
Other Guidance
    The FAA also will develop additional guidance and training material 
for FAA Aviation Safety Inspectors (ASIs), and representatives of the 
Administrator authorized to conduct the inspections and records reviews 
specified in this rule prior to the conduct of those inspections and 
reviews.

Significant Changes

    Based on the comments received the FAA made several significant 
changes to the proposed rule language in notice No. 99-02. The revised 
rule language is part of this final rule.
    The FAA extended the repeat inspection and records review interval 
from 5 years to 7 years to allow operators to align inspection and 
records review intervals more closely with scheduled HMC intervals.
    Also, while notice No. 99-02 specified that inspections should be 
established for affected airplanes using damage tolerance techniques, 
this final rule adds an exception for multiengine airplanes initially 
certificated with nine or fewer passenger seats and operated under part 
129 and part 135 scheduled operations. The requirement to keep flight 
cycles has been removed. Those airplanes can have a service-history-
based SSIP instead of a damage-tolerance-based SSIP.
    In addition, the FAA extended the 3-year requirement for initial 
inspections on airplanes over 24 years old to 4 years. This will 
provide the FAA with additional time to develop guidance and training 
material for designees and FAA inspectors.
    Finally, the FAA has decided not to apply this final rule to 
airplanes operated by a certificate holder between any point within the 
State of Alaska and any other point within the State of Alaska.

Discussion of Comments

    A total of 63 commenters submitted 247 comments to Docket No. FAA-
1999-5401. Commenters generally opposed the proposal; they submitted 
131 comments against the proposed rule and 16 comments in support of 
the changes. In addition, 100 comments either included supplementary 
information or did not clearly argue for or against the proposed rule. 
A discussion of comments submitted, organized by issue, follows.

Statutory Requirements

    Section 44717 of 49 U.S.C. requires the following actions:
    [sbull] The Administrator must ``prescribe regulations that ensure 
the continuing airworthiness of aging aircraft.''
    [sbull] The Administrator must ``make inspections, and review the 
maintenance and other records, of each aircraft an air carrier uses to 
provide air transportation.'' These inspections and reviews ``shall be 
carried out as part of each HMC of the aircraft conducted after the 
14th year in which the aircraft has been in service.''
    [sbull] Each air carrier must ``demonstrate to the Administrator, 
as part of the inspection, that maintenance of the aircraft's age-
sensitive parts and components has been adequate and timely enough to 
ensure the highest degree of safety.''
    [sbull] Each air carrier must make its aircraft, as well as any 
records about the aircraft that the Administrator may require to carry 
out the review, available for inspection as necessary to comply with 
the rule issued by the Administrator.
    [sbull] The regulations must establish procedures to be followed 
for carrying out such an inspection.
Applicable Airplane Types
    Comments: Some commenters indicate the NPRM addresses more airplane 
types than the AASA intended to address. Because the AASA specifies 
inspections and reviews must be carried out as part of each HMC of an 
airplane and light airplanes do not undergo HMCs, the National Air 
Transportation Association (NATA) asserts the AASA was not intended to 
address light airplanes. The NATA further contends the proposal 
disregards the unique inspection programs of light airplanes, and 
claims the FAA has not found deficiencies in those programs. Also 
according to the NATA, the FAA has not proven through inspections, 
maintenance reviews, or research that light airplanes are unsafe. 
Accordingly, the NATA states that the FAA is not justified in requiring 
small businesses that operate light airplanes to invest large sums of 
money in developing and implementing an inspection program intended for 
larger airplanes. The State of Alaska Department of Transportation and 
Public Facilities (ADOT&PF) agrees with the NATA's position.
    FAA Response: The FAA disagrees. The AASA does not specifically 
address types of aircraft. It applies to ``each aircraft an air carrier 
uses to provide air transportation.'' This includes all air carriers, 
including smaller operators who conduct commuter operations, regardless 
of the size of the airplane. However, in response to commenters' 
concerns, the FAA is revising the provisions of the rule pertaining to 
the imposition of requirements for supplemental inspection programs. 
The

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final rule permits relief from the requirement for all affected 
airplanes to have damage-tolerance-based inspections and procedures in 
their aircraft maintenance and inspection programs. All multiengine 
airplanes initially certificated with nine or fewer passenger seats may 
have service-history-based SSIPs instead of damage-tolerance-based 
inspections and procedures. These regulations will be implemented in 
2010. Service-history-based SSIPs are estimated to cost significantly 
less than damage-tolerance-based SSIPs to develop and implement. In 
addition, airplanes operating between any point within the State of 
Alaska and any other point within the State of Alaska are exempt from 
the requirements of this final rule.
U.S. Military Airplanes
    Comments: Many commenters question which types of airplanes or 
operations would be affected by the proposal. One commenter asks 
whether the proposal would apply to U.S. Air Force commercial 
derivative airplanes (that is, Boeing 737 airplanes operated by the 
U.S. Air Force). The commenter notes the Air Force requires Boeing to 
comply with FAA directives and rules on those derivative airplanes. 
Another commenter asks whether the proposal would apply to Boeing 757 
executive airplanes (military C-32 program).
    FAA Response: This final rule only applies to specified airplanes 
operating under parts 121, 129, and 135. Aircraft that are not U.S.-
registered and operated by the U.S. military are not required to comply 
with the provisions of this rule. However, any U.S.-registered aircraft 
operating under part 121, 129, or 135 is subject to the requirements of 
the rule, regardless of the status of its operator.
Imported Older Airplanes
    Comments: One commenter questions how the proposal would affect 
requirements for imported airplanes older than 14 years. The commenter 
notes 44 countries have safety standards for imported airplanes and the 
United States is not among those countries. According to the commenter, 
the 100-hour inspection (appendix D to 14 CFR part 43) is the closest 
the United States comes to having such a requirement, but most DARs and 
many FAA regions ignore this requirement.
    FAA Response: The FAA disagrees. The proposal was intended to bring 
airplanes under the Aging Airplane Program after the effective date of 
the rule. Therefore, with respect to the requirements of this rule, an 
imported airplane brought into operation under part 121, 129, or 135 
will not differ from an airplane used domestically under 14 CFR part 91 
and brought into operation under parts 121, 129, or 135; each airplane 
will have to be brought under the appropriate maintenance or inspection 
program and undergo the applicable aging airplane inspections and 
records reviews prior to being operated under those parts. 
Additionally, any airplane, domestic or imported, that does not have a 
supplemental inspection program that meets the requirements of this 
rule will not be eligible for air carrier operations after the dates 
specified in this rule.
Applicable Operations
    Comments: The Alaska Air Carriers Association (AACA) opposes the 
proposal and states it should be withdrawn. According to the AACA, the 
NPRM could lead to the end of scheduled turbopropeller commuter airline 
growth in Alaska and force a return to the use of out-of-production, 
piston-powered, single-engine airplane operations in rural Alaska. The 
AACA contends this proposal would force air carriers that have reached 
the financial and operational thresholds of using larger, turbine-
powered equipment to pay a ``compliance penalty'' to operate that 
equipment. Additionally, the AACA contends many of Alaska's rural 
communities would experience decreased air service and increased costs 
of living, and be forced to accept travel in smaller airplanes known to 
have six times more accidents than twin-engine airplanes used 
currently.
    The AACA notes the FAA has implemented numerous significant 
regulatory changes during the past 15 years (for example, the 
``Commuter Rule''), but the aviation safety record in Alaska has not 
changed significantly, despite the high costs.
    According to the AACA, some additional safety measures are 
necessary. However, the AACA states measures in Alaska should include 
(1) restoring the previous high levels of service from Flight Service 
Stations; (2) improving aviation weather reporting, forecasting, 
information distribution, and air-to-ground communications facilities; 
and (3) developing additional navigational aids and approach procedures 
to allow instrument flight rules flight and airport runway, ramp, and 
apron improvements.
    As an alternative to the proposal, the AACA states it would develop 
an FAA-approved program to accommodate the additional safety intent of 
the rule, addressing safety as well as the operational limitations 
unique to Alaska. The program would provide guidance, through 
development of a customized and comprehensive training program for 
regularly scheduled maintenance and inspection procedures. To ensure 
compliance with this initiative, the program would include an 
independent audit element and be made available to all members of the 
AACA, as a function of the AACA Safety and Resource Center.
    The State of Alaska Department of Transportation and Public 
Facilities (ADOT&PF) noted that ``this NPRM, over the next ten years 
has the potential to effectively economically shut down multiple 
aircraft operators in Alaska.'' The ADOT&PF further stated that the 
number of aircraft impacted is nearly 100 percent of the twin-engine 
aircraft fleet servicing Alaska aviation needs. These comments were 
echoed by a number of Alaska operators that stated that implementation 
of the NPRM would result in the ``termination'' of their operations and 
that ``the nature of the rural transportation infrastructure in Alaska 
requires relief from these requirements.''
    According to the NATA, the proposal would substantially affect 
interstate commerce in many areas, including Nevada, Arizona, New 
England, and the southeastern United States. Also, the NATA asserts 
this proposal may cripple the majority of the State of Alaska's 
transportation network.
    FAA Response: The FAA has received numerous comments noting the 
possible effect of the proposal on intrastate aviation in Alaska. The 
FAA notes however that the proposal would not apply to aircraft 
operated by a certificate holder in on-demand or cargo-only operations 
conducted under part 135. This exclusion remains in the final rule.
    The FAA also recognizes that the AASA does not specifically mandate 
the supplemental inspections proposed in notice 99-02 and set forth in 
this rule. However, the FAA clearly is within its authority to require 
such inspection programs under its broad mandate to promote safety as 
set forth in 49 U.S.C. 44701.
    The FAA also notes that Congress, both in the Federal Aviation 
Reauthorization Act of 1996 (Public Law 104-264) and in the Wendell H. 
Ford Aviation Investment and Reform Act for the 21st Century (Public 
Law 106-181), required the Administrator ``in amending title 14, Code 
of Federal Regulations, in a manner affecting intrastate aviation in 
Alaska * * * to consider the extent to which Alaska is not served by 
transportation modes other than aviation and * * * establish such 
regulatory distinctions the Administrator considers appropriate.''

[[Page 72730]]

 Section 40113 of 49 U.S.C. was amended to effectuate this provision.
    In view of the clear Congressional mandate for the FAA to consider 
the unique role of aviation in providing transportation within the 
State of Alaska and the possible loss of critical air services to rural 
communities within the State, the FAA has revised the proposal. The 
final rule will not apply to aircraft operated by certificate holders 
between any point within the State of Alaska and any other point within 
the State of Alaska.
Regulatory Activity Since 1991 and Recordkeeping
    Comments: One commenter states that the proposal seems to disregard 
all regulatory activity since 1991 that addresses aging airplanes, as 
well as existing recordkeeping requirements to show compliance with 
such aging airplane activity.
    FAA Response: The FAA disagrees. The FAA has taken into account 
relevant regulatory activity since 1991 in the development of this 
rule, such as CPCPs, structural modification programs, the repair 
assessment rule, and SSIPs. In spite of these regulatory activities, we 
continue to believe the additional inspections and records reviews are 
warranted to ensure age-sensitive parts and components are maintained.
Inspections and Records Reviews
    Comments: Some commenters state the proposal does not meet the 
intent of the AASA. According to the Air Transport Association of 
America (ATA), FAA requirements exceed AASA requirements in the 
proposal by requiring an unsegmented simultaneous review of each 
affected airplane and its records. The ATA also notes the AASA does not 
require the FAA to establish how often airplane inspections and records 
reviews must be conducted. The Regional Airline Association (RAA) 
agrees with the ATA and further asserts that the AASA is not intended 
to disrupt an air carrier's maintenance program, but the FAA proposal 
certainly would force air carriers to change their programs at 
considerable cost.
    FAA Response: To minimize cost, operators who have segmented 
maintenance programs, progressive inspection programs, or approved 
aircraft inspection programs (AAIPs) should work with their principal 
maintenance inspector (PMI) or DAR to agree on which inspection 
examines the largest portion of the airplane. The operator can make the 
airplane available to the FAA during that inspection to ensure the 
inspection and records review required by this rule is complied with in 
a comprehensive, efficient, and cost effective manner. However, the 
operator using a segmented maintenance program, progressive inspection 
program, or AAIP must recognize that the PMI or DAR conducting the 
inspection may require additional areas of the airplane to be open and 
available for inspection at the discretion of the FAA.
    As mentioned previously, the FAA has changed the inspection and 
records review interval from 5 years to 7 years to allow operators to 
align their aircraft inspection and records review intervals more 
closely with scheduled HMC intervals.
Damage-Tolerance-Based Inspection Techniques
    Comments: The General Aviation Manufacturer's Association (GAMA) 
contends that the AASA does not direct the FAA to specify damage 
tolerance analysis and inspection techniques as the only acceptable 
method for ensuring the continued airworthiness of aging airplane 
structural designs certificated before such techniques were available. 
The GAMA states there are other methods that have been developed in 
conjunction with the FAA and industry that are based on structural 
fatigue analysis, fatigue tests, and field experience correlation, 
where applicable.
    FAA Response: The FAA agrees that the AASA does not specifically 
require the FAA to mandate the use of damage-tolerance-based inspection 
techniques. However, 49 U.S.C. 44717 states that the Administrator 
``shall prescribe regulations that ensure the continuing airworthiness 
of aging aircraft'' and that the Administrator shall make the necessary 
inspections ``that the Administrator decides may be necessary to enable 
the Administrator to decide whether the aircraft is in safe 
condition.''
    The FAA recognizes that there was a collaborative effort based on 
the use of structural fatigue analysis, fatigue tests, and field 
experience correlation to develop appropriate inspections and 
procedures to ensure the continuing airworthiness of aging aircraft. 
The FAA, however, has determined that except for those multiengine 
airplanes initially certificated with nine or fewer passenger seats 
operated under part 129 or used in scheduled operations under part 135, 
these inspections and procedures should be established using damage-
tolerance-based techniques. Those multiengine airplanes initially 
certificated with nine or fewer passenger seats can use inspection 
programs that include service-history-based inspections and procedures 
instead of damage-tolerance-based inspections and procedures.
Requirements Beyond the Scope of the AASA
    Comments: The ATA states the proposal goes beyond inspections and 
records reviews by supplementing airplane type design and requiring 
that airplanes meet certification requirements developed quite 
recently. According to the ATA, if necessary, the proposal should be 
framed as an AD, and ``manufacturers'' should be required to adapt 
their maintenance programs. According to the ATA, ``manufacturers'' are 
in a better position than operators to have the design data and service 
history required to modify their programs.
    FAA Response: The FAA agrees that the rule, in certain aspects, 
exceeds the AASA's mandate to conduct inspections and records reviews. 
The AASA requires an initial inspection as part of each HMC of the 
aircraft conducted after the beginning of an airplane's 14th year in 
service, and thereafter at each HMC. It does not establish specific 
inspection intervals based on calendar time nor does it mandate the 
requirement for an operator to include specific supplemental inspection 
procedures in an aircraft's maintenance program.
    Yet, as stated in the preamble to the NPRM and in keeping with the 
AASA's mandate to ensure the continuing airworthiness of aging 
aircraft, the FAA considered options for setting repeat inspection 
intervals. The FAA reviewed the variables used in establishing the 
parameters used by operators to carry out scheduled maintenance 
requirements such as flight hours, calendar time, or a combination of 
both. The FAA also considered the phasing and segmenting of HMCs and 
found that the intervals varied from 1 to 27 years. Therefore, the FAA 
chose to establish a fixed repeat inspection interval.
    The FAA realizes that the repeat inspections established in this 
final rule may not be consistent with current operator maintenance 
schedules. However, the FAA notes that the ATA itself, in memorandum 
96-AE-014, dated March 11, 1996, recommended that ``a `C' check 
compliance period (18 months) or `D' check period (5 years) be adopted 
for all rules unless it can be shown that a shorter time interval is 
required for safety reasons.'' The FAA, in keeping with the AASA's 
mandate, established a repeat inspection interval as part of this final 
rule.
    The FAA does not agree that ADs should be used to implement the new 
requirements. The FAA is not issuing

[[Page 72731]]

this rule to address an unsafe condition. This rule is to ensure the 
continuing structural airworthiness of air carrier aircraft as they 
continue in service. Also, this rule will allow operators the 
flexibility to adjust their maintenance or inspection program based on 
service history and design review.
    Furthermore, applying the AASA requirements to all airplanes, 
regardless of operation, would go significantly beyond the mandate of 
the act, which requires the Administrator to issue a rule requiring an 
inspection and records review of each aircraft used in air 
transportation for compliance with aging aircraft requirements.
    Using operational rules (parts 121, 129, and 135) to mandate 
inspections, supplemental inspections, and records reviews is 
compatible with what the FAA has done with other maintenance and 
inspection programs, such as those specified in the final rule 
entitled, ``Repair Assessments for Pressurized Fuselages,'' which was 
published in the Federal Register on April 25, 2000 (65 FR 24108). It 
also corresponds more closely to the intent Congress specified in the 
applicability of the AASA.

Inspections

    Summary of Proposal/Issue: The purpose of the proposal was to 
verify that each operator can demonstrate it has accomplished all 
required maintenance tasks, including the damage-tolerance-based SSIPs 
proposed in the NPRM. The AASA specifies that the inspections and 
records reviews be carried out as part of each airplane's HMC after the 
14th year in service. The NPRM divides airplanes into three categories 
for these inspections to ensure the oldest airplanes are inspected 
first. The NPRM also proposes that all aging airplane inspections and 
records reviews be repeated at specified intervals. However, the 
proposal includes a provision for extending the thresholds and 
intervals to accommodate unforeseen scheduling conflicts.
    The NPRM also requires operators to notify the FAA within a 
specific time period before an airplane is available for an inspection 
and records review.
Existing Maintenance Programs Make the Rule Redundant
    Comments: Most commenters believe the requirement to accomplish 
inspections and records reviews is redundant. One operator asserts 
``every air carrier'' already has a continuous airworthiness program 
and an FAA-approved maintenance program, which include corrosion 
prevention, corrosion control, and damage-tolerance-based SSIPs. Also, 
that operator believes ``every'' carrier also must have a Continuing 
Analysis and Surveillance System (CASS) and must analyze structural 
defects for their approved maintenance reliability programs for 
principal structural elements. The commenter notes the regulation and 
oversight of maintenance programs is a daily FAA requirement. The ATA 
notes FAA Certificate Management Offices are responsible for overseeing 
an air carrier's Continuous Airworthiness Maintenance Program (CAMP) 
and CASS and ensuring an air carrier's airplanes are operated and 
maintained according to FAA regulations and the air carrier's 
operations specifications. The ATA notes these responsibilities do not 
begin only after an airplane has been in service for 14 years. 
Furthermore, the RAA emphasizes that the FAA has complete authority to 
determine whether an operator has deficiencies in its maintenance 
program.
    One commenter states that the FAA should revise the proposal to 
compensate for existing maintenance programs that address aging 
airplane concerns. For example, the 14-year in-service threshold should 
be increased to 20 years to coincide with the Aging System Task Force 
definition, which established ``20 years since an airplane's 
certification'' as the nominal age threshold. Another commenter states 
that the FAA should provide special consideration for low-utilization 
airplanes that may have more than 14 years of total service. A third 
commenter states the proposed inspections should be associated with the 
renewal or continued effectiveness of ``an airline's standard 
airworthiness certificate'' and should include all phases of continued 
airworthiness in addition to aging airplane considerations. However, 
that commenter questions the reason for a 14-year time period. The Air 
Line Pilots Association (ALPA), however, supports proposed inspections 
for airplanes after 14 years in service.
    FAA Response: The requirements to accomplish inspections and 
records reviews stem directly from the AASA, which states, in part, 
that the FAA shall prescribe regulations that ``at a minimum, require 
the Administrator to make such inspections, and conduct such reviews of 
maintenance and other records, of each aircraft used by an air carrier 
to provide air transportation as may be necessary to enable the 
Administrator to determine that such aircraft is in safe condition and 
properly maintained for operation in air transportation.''
    In addition, the AASA specifies that inspections and records 
reviews ``shall be carried out as part of each heavy maintenance check 
of the aircraft conducted after the 14th year in which the aircraft has 
been in service.''
Differences Between Current and New Inspections and Records Reviews
    Comments: Several commenters are uncertain how the proposed 
inspections and records reviews would differ from those currently 
conducted by ASIs. The ATA notes that Sec.  121.153(a) currently 
requires airplanes to be maintained in an airworthy condition, which 
would include compliance with any mandated aging airplane requirements. 
Also, some commenters contend this proposal represents a shift of 
responsibility from air carriers to the FAA in ensuring airplane 
airworthiness. These commenters state they are uncertain why the FAA 
desires such a shift.
    Another commenter recommends that the FAA allow an air carrier's 
quality assurance department to conduct the proposed inspections and 
records reviews when an FAA representative is unavailable. ALPA 
supports the proposal, which would permit certain representatives of 
the Administrator to conduct inspections.
    FAA Response: Section 44717(b)(2) 49 U.S.C. states that the aging 
aircraft inspections ``shall be carried out as provided under [49 
U.S.C.] Sec.  44701(a)(2)(B) and (C) * * *'' (emphasis added). Section 
44701(a) reads as follows:

    (a) The Administrator of the Federal Aviation Administration 
shall promote safe flight of civil aircraft in air commerce by 
prescribing * * *
    (2) Regulations and minimum standards in the interest of safety 
for * * *
    (B) Equipment and facilities for, and the timing and manner of, 
the inspecting, servicing, and overhauling (of aircraft, aircraft 
engines, propellers, and appliances); and
    (C) A qualified private person, instead of an officer or 
employee of the Administrator, to examine and report on the 
inspecting, servicing and overhauling.

    Section 44717(b)(2) was added in 1994 as part of the recodification 
of the FAA's enabling legislation. The AASA and the recodified Sec.  
44717(a)(1) require the Administrator to make the aging airplane 
inspections.
    The rules prescribed by the Administrator under Sec.  
44701(a)(2)(B) establish regulations and minimum standards for many 
different activities by nongovernment persons, including air carrier 
maintenance organizations and repair stations. Section 44701(a)(2)(C) 
requires the

[[Page 72732]]

Administrator to establish regulations and minimum standards for 
qualified private persons who examine and report on inspecting, 
servicing, and overhauling. It does not address the delegation of 
authority to act on behalf of the Administrator nor does it describe 
persons who act on behalf of the Administrator. A certificate holder 
and its employees are not employees of the Administrator, nor are they 
necessarily representatives of the Administrator in accordance with 
Sec.  44702(d).
    Congress clearly intended that the Administrator would determine 
``whether an aircraft is in safe condition and maintained properly for 
operation in air transportation.'' This is evident in Sec.  
44717(a)(1), which requires the Administrator to perform the 
inspections and records reviews. It also is consistent with the 
legislative history of the AASA. The FAA notes, however, the AASA was 
never intended to relieve the operator from the responsibility for the 
airworthiness of the aircraft as described in current Sec.  121.363, 
Sec.  129.14 (ICAO Annex 6, chapter 8), or Sec.  135.413. there is no 
language in Sec.  44717 that implies that operators are to be relieved 
of compliance with regulations issued under Sec.  44701.
    Furthermore, the FAA notes that the text of the AASA, and the 
recodification thereof, instructs the Administrator to establish a 
program to provide FAA inspectors and engineers with the necessary 
training to conduct auditing inspections of airplanes operated by air 
carriers for corrosion and metal fatigue (see Sec.  44717(c)(2)(A)). If 
it had been the intent of Congress to have private persons make those 
inspections instead of FAA employees (or perhaps designees), that text 
would have been changed.
    The above interpretation is also consistent with the general 
position that the recodification of the FAA's enabling act was not 
intended to change the substantive law.
    Given the extensiveness of the scope and quantity of airplane 
inspections required by Sec.  44717(a)(1), the Administrator could 
still elect to use ``a qualified private person'' to conduct those 
inspections and records reviews under a delegation of authority. Hence, 
the FAA intends to use DARs to help in conducting the inspections and 
records reviews required by Sec.  44717(a)(1). Such action is 
consistent with the act and gives meaning to the provisions of 49 
U.S.C. 44717(b)(2) in its context. This interpretation also gives 
meaning to ``qualified private person'' in the context of implementing 
the Aging Airplane Program.
Incompatibilities Between Current Practices and the Proposal
    Comments: One commenter emphasizes that current regulations do not 
allow a used airplane to be placed on an operator's certificate until 
its records have been reviewed by the Administrator. Another commenter 
notes a complete records review is not possible for some airplanes 
because the history of those airplanes has not been maintained. Yet 
another commenter asserts compliance with current FAA-scheduled 
maintenance program requirements along with FAA verification of records 
accuracy on a routine interval is a more logical approach than that 
presented in the proposal.
    FAA Response: The FAA disagrees. Section 44717, 49 U.S.C. states 
that the FAA--

shall prescribe regulations that ensure the continuing airworthiness 
of aging aircraft and that the Administrator shall make the 
inspections, and review the maintenance and other records of each 
aircraft an air carrier uses to provide air transportation that the 
Administrator decides may be necessary to enable the Administrator 
to decide whether the aircraft is in safe condition.

    The statute further specifies that these regulations shall--

require an air carrier to demonstrate to the Administrator, as part 
of the inspection, that maintenance of the airplane's age-sensitive 
parts and components has been adequate and timely enough to ensure 
the highest degree of safety.

The alternate courses of action described by commenters, including 
existing practices, do not relieve the FAA of its obligations under the 
statute.
Burdens of Proposed Inspection Intervals
    Comments: Many commenters assert the proposal is burdensome to 
operators and the FAA. The ATA states the proposal for inspections at 
5-year intervals is contrary to the intent of the AASA and would 
require air carriers to redefine their maintenance programs to match 
the 5-year intervals. According to the ATA, the FAA may be exceeding 
its mandate if this requirement is implemented. Several commenters 
support the ATA's position stating that the FAA should revise the 
proposal so inspection intervals align with operator maintenance 
programs. One commenter asserts the first inspection after the rule 
becomes effective should be required 5 years from the rule's effective 
date or during the next HMC, whichever is later, regardless of the age 
of the airplane.
    The ATA asserts that the inspection interval requirement would 
subject carriers to disruptions if the FAA fails to provide the air 
carrier with timely notice that the aging airplane inspections and 
records reviews have been completed. The proposal states that the FAA 
may take an airplane out of service before analyzing the results of an 
aging airplane inspection and records review.
    FAA Response: The FAA recognizes that the AASA does not establish 
specific repeat inspection intervals based on calendar time. However, 
because of the wide variances in HMC intervals and maintenance 
programs, the FAA chose to establish a fixed repeat interval. The FAA 
notes that HMC intervals vary greatly among operators. Operators have 
segmented maintenance programs, progressive inspection programs, or 
approved aircraft inspection programs that do not easily lend 
themselves to the use of HMC intervals for the conduct of the mandated 
inspections and records reviews.
    Even though the AASA requires an initial inspection as part of each 
HMC after the beginning of an airplane's 14th year in service, and 
thereafter at each HMC, the FAA believes that an inspection interval 
based on calendar time is consistent with the AASA. A fixed repeat 
interval is consistent with the intent of the AASA that requires the 
Administrator to ``assure the continuing airworthiness of aging 
aircraft.'' The repeat intervals established in the rule will allow the 
Administrator to ensure that ``each aircraft used by an air carrier to 
provide air transportation is in a safe condition and properly 
maintained for operation in air transportation.''
    As previously noted, the ATA recommended, in memorandum 96-AE-014, 
dated March 11, 1996, that ``a `C' check compliance period (18 months) 
or `D' check period (5 years) be adopted for all rules unless it can be 
shown that a shorter time interval is required for safety reasons.'' 
The FAA, in keeping with the AASA's mandate, established a repeat 
inspection interval as part of this final rule that is consistent with 
this recommendation.
    The FAA realizes that the repeat inspection intervals established 
in this final rule may not be consistent with current operator 
maintenance schedules. Therefore, based on the comments received, the 
FAA has changed the proposed 5-year repeat interval to a 7-year 
interval to be more compatible with air carriers' HMCs.
    In addition, the FAA extended the 3-year requirement for initial 
inspections on airplanes over 24 years old to 4 years to provide the 
FAA with additional time to develop guidance and training

[[Page 72733]]

material for designees and FAA inspectors.
Ninety-Day Reporting Requirement
    Comments: The ATA believes the FAA should modify the proposal to 
allow 90 days for an operator to provide a report to the Administrator 
on findings and conclusions related to aging airplane effects from an 
HMC and the maintenance activities in the interval since that HMC. 
Additionally, the ATA recommends the FAA provide a similar 90-day 
timeframe during which the FAA would be required to provide an operator 
with written acknowledgment of such a report and a determination of the 
FAA's acceptability.
    One ATA member suggests that an operator submit a summary report, 
for like airplanes in the air carrier's fleet, of findings and 
conclusions related to aging airplane effects from the HMC and the 
maintenance activities in the interval since that HMC within 60 days of 
each 90-day period. According to this ATA member, quarterly summary 
reports can depict trends more easily than individual airplane check 
reports.
    FAA Response: The FAA agrees that submission of a 90-day inspection 
and records review report would be a beneficial practice. This should 
be agreed to between each operator and its PMI. However, because this 
would add a burden to operators and was not required by the AASA, such 
a report will not be added to the final rule but will be an acceptable 
option to assist operators in demonstrating compliance with the 
provisions of this rule.
Accomplishment of Records Reviews and Inspections
    Comments: One commenter asserts the proposal could result in 
enormous costs to operators if ASIs or DARs fail to make inspections 
and reviews in a timely manner. Also, the RAA states that the proposal 
that an air carrier cannot operate its airplanes until inspections and 
records reviews are completed is excessive. The RAA is particularly 
concerned about such a case in which the lack of personnel to conduct 
an inspection and records review causes grounding of an airplane. Other 
commenters question the FAA's ability to conduct or train 
representatives to perform the proposed inspections and reviews. One 
commenter states that the FAA should consider an alternative to the 
inspections and records reviews that would have an ASI or DAR at an air 
carrier's facility each night a carrier conducts a scheduled segmented 
inspection.
    FAA Response: The FAA acknowledges the commenter's concerns. To 
ensure rapid implementation of the inspections and records reviews, 
this final rule includes provisions to allow for DARs to perform those 
required inspections and reviews. The FAA anticipates that there will 
be an increased demand for DARs as a result. In the short run, this may 
create problems with the availability of DARs, given their current 
supply and the time it takes for an individual to become a DAR. Over 
time, it will be possible for qualified individuals to become DARs and 
fill the demand. Additionally, the FAA will not require operators of 
affected aircraft to immediately comply with the inspections and 
records reviews after the effective date of the rule. Significant 
multi-year implementation periods have been provided in the rule to 
ensure sufficient trained personnel will be available to accomplish the 
inspections and reviews without disruption to certificate holders' 
operations. As a result, the industry's needs will be met and operators 
will be able to comply with the requirements of the AASA in a timely 
manner.
    Also, operators should be aware that while this final rule imposes 
restrictions on airplanes operating under parts 121, 129, and 135 until 
the required inspections and records reviews have been accomplished, it 
does not affect any part 91 operations conducted by part 121, 129, and 
135 air carriers, such as training or positioning flights.
    Regarding the comment on the effects of the rule and the FAA's 
workload, the FAA is committed to train a group of inspectors and DARs 
to perform the inspections and records reviews required by this final 
rule. The FAA will also monitor the performance of those inspectors and 
DARs.
    Each operator should plan each inspection and records review and 
schedule it with the appropriate ASI or DAR. The ASI/DAR inspection and 
records review should normally follow the inspection by maintenance 
personnel. However, if an unforeseen scheduling conflict occurs, the 
final rule permits a 90-day extension to accomplish the inspection and 
records review. An unforeseen scheduling conflict may arise, for 
example, if an operator finds that the hangar space dedicated for the 
incoming aircraft is not available because of additional work required 
on the aircraft currently in the hangar. The Administrator may approve 
an extension of up to 90 days, provided the operator presents to the 
PMI written justification for the scheduling conflict. Also, the FAA 
will accept electronic, facsimile, or other forms of notification. The 
request for an extension should provide the PMI ample opportunity to 
respond to the operator's request.
Single Airplane Versus Fleets
    Comments: Several operators note the proposal would require review 
of airplanes on an individual basis rather than as a fleet. These 
operators strongly oppose the proposal, indicating the process would be 
too expensive, time-consuming, and unlikely to increase airplane 
safety. According to these operators, most audit programs sample the 
fleet and require additional review only when problems are discovered. 
One commenter recommends that the FAA implement a fleet sampling 
program beginning with the oldest airplanes in a fleet type, with 
inspections every 5 years on a different airplane within that fleet. 
Another commenter recommends the FAA allow air carriers to complete 
these remaining airplane inspections and records reviews.
    FAA Response: The FAA disagrees. The AASA states that each airplane 
that has exceeded its 14th year in service should have an inspection 
and records review to determine the adequacy and timeliness of the 
maintenance of the aircraft's age-sensitive parts and components. 
Therefore, fleet audit programs do not meet the Congressional mandate 
and are not suitable.
    The FAA again notes that the proposed 5-year interval has been 
changed to a 7-year interval to be more compatible with the air 
carriers' HMCs. However, with respect to air carriers completing 
inspections and records reviews, the AASA states specifically that the 
Administrator must accomplish the required inspections and records 
reviews.
    The FAA recognizes that operators will incur additional expenses as 
a result of this rule. The FAA has therefore worked to minimize the 
cost. Affected airplanes initially certificated with nine or fewer 
passenger seats have been allowed to have incorporated into their 
inspection program service-history-based SSIPs instead of damage-
tolerance-based SSIPs. Additionally, provisions that allow for delayed 
compliance until 2010 of certain airplanes with damage-tolerance-based 
and service-history-based inspection programs have also been included 
in the rule.
Limiting Inspection Scope
    Comments: The ATA recommends requiring only that portion of an 
airplane scheduled for detailed maintenance and repair at an HMC after

[[Page 72734]]

the 14th year of service be made available along with corresponding 
records. According to the ATA, this revision of the proposal would 
allow the air carrier to demonstrate the adequacy and timeliness of its 
continuous maintenance and surveillance programs and other aging 
airplane programs without having to examine every part, component, or 
record of an airplane.
    FAA Response: The FAA agrees in part. As stated in the NPRM--

    Although it is the FAA's intent to carry out records reviews and 
inspections to the extent that the aircraft structure is accessible 
during the HMC maintenance visit, the FAA may require additional 
access to determine that the maintenance of the airplane's age-
sensitive parts and components has been adequate and timely.

The FAA expects the air carrier to identify the most comprehensive HMC 
within the interval identified in the rule as the time for the conduct 
of the inspections and records reviews.
    The intent of the final rule is that aging airplane inspection and 
records reviews should be concurrent with the HMC maintenance being 
accomplished on each airplane and the FAA has revised the rule to 
facilitate this action.
Access to Airplane Structure
    Comments: Many commenters express concern about allowing an ASI or 
DAR access to areas of inspected airplanes that may not be opened 
during HMCs to determine whether the airplanes meet the requirements of 
the NPRM. These commenters question what criteria would be used to 
determine whether such additional access is required. The ATA contends 
if additional access is required, it should be negotiated in advance 
with the air carrier or mandated under existing authority without 
signaling ASIs or DARs that they should be opening additional areas at 
all HMCs.
    FAA Response: The FAA disagrees. It is not the FAA's intent to 
disrupt operators' scheduled maintenance in such a way that it would 
impact their schedules. However, each airplane subject to the final 
rule cannot be returned to service until the Administrator or a 
designee has completed its inspection and records review and notifies 
the operator accordingly. The FAA agrees that it would behoove the 
operator to schedule these inspections with the ASI or DAR well in 
advance of scheduled maintenance visits; however, the FAA does not 
intend to limit its access to those areas inspected under the 
provisions of the operator's appropriate maintenance or inspection 
program.
    Although it is the FAA's intent to carry out the inspections and 
records reviews to the extent that the airplane structure is accessible 
during the maintenance visit, at the discretion of the ASI or DAR, the 
FAA may require additional access to confirm that the maintenance of 
the airplane's age-sensitive parts and components has been adequate and 
timely as required by the AASA.
Acceptable Records
    Comments: The ATA states that conflicts would undoubtedly arise 
when an airplane is inspected and the records for that airplane are 
located elsewhere. The ATA asserts an air carrier should not be 
required to move the airplane or its records in such cases. Several 
commenters agree with the ATA's position. According to the ATA, the FAA 
should allow for the use of electronic or other copies of records. 
Also, the ATA states that the FAA should allow for the use of a summary 
of maintenance actions in place of original airplane records, to focus 
on aging effects rather than recordkeeping compliance. The Aerospace 
Industries Association of America, Inc. (AIAA), opposes the potential 
need to maintain a duplicate set of records. The AIAA further contends 
that reliance on automated records is inadequate, even though it may 
help ensure consistency in format.
    FAA Response: The FAA agrees with commenters that these are 
legitimate issues related to airplane records. The FAA recognizes that 
airplanes subject to this rule are maintained at FAA-approved repair 
stations throughout the world. It would place an undue burden on the 
air carrier or operator to provide original maintenance records that 
are kept at their main base. Therefore, the FAA will accept a status 
summary of maintenance actions in lieu of original airplane records 
provided the status summary meets the requirements of the rule. Also, 
the FAA will accept electronic, facsimile, or other copies of airplane 
records as long as the information is accurate and complete. These 
details should be coordinated individually with each ASI or DAR.
Sixty-Day Notification Requirement
    Comments: Several commenters object to the requirement that an air 
carrier must notify the Administrator 60 days before an airplane and 
its records are available for review. According to one commenter, 
although the current proposal increases the advanced notification 
requirement from 30 days (as set forth in the Aging Airplane Safety 
NPRM published October 5, 1993 (58 FR 51944)) to 60 days, it does not 
respond to the original complaints by several commenters that normal 
surveillance of an operator's fleet would provide the FAA with ample 
time to find out the details of a carrier's heavy maintenance schedule.
    FAA Response: The FAA disagrees. In 1993, the FAA proposed in its 
Aging Airplane Safety NPRM a 30-day time period to notify the 
Administrator before an airplane and its records would be available for 
review. In notice no. 99-02, the FAA extended this time period to 60 
days. The FAA believes that this notification is necessary because 
notification obtained through normal surveillance of an operator's 
fleet may be insufficient to ensure the FAA has sufficient time to 
schedule its resources and minimize the impact on the air carrier.
Ninety-Day Extensions
    Comments: One ATA member states the proposed 90-day extension 
provisions should be open-ended to take into account unforeseen 
scheduling conflicts of an airplane and possible delays resulting from 
FAA resource constraints. However, the ATA generally supports the 
extension provision.
    FAA Response: The FAA disagrees and contends that 90 days is a 
sufficient time period for an operator to resolve an unforeseen 
scheduling conflict. Operators must therefore plan to account for this 
requirement. An unforeseen scheduling conflict may arise, for example, 
if an operator finds that the hangar space dedicated for the incoming 
aircraft is not available because of additional work required on the 
aircraft currently in the hangar. The Administrator may approve an 
extension of up to 90 days, provided the operator presents to the PMI 
written justification for the scheduling conflict. Also, the FAA will 
accept electronic, facsimile, or other forms of notification. The 
request for an extension should provide the PMI ample opportunity to 
respond to the operator's request. The 90-day extension provision is 
adopted as proposed.
Cargo-Modified Airplanes
    Comments: According to comments, the FAA should create a separate 
category of inspections for cargo-modified airplanes to require shorter 
intervals between their baseline inspection programs, unless the FAA 
takes into account enough precautions during the supplemental type 
certificate (STC) substantiation process.
    FAA Response: The FAA disagrees. The final rule is applicable to 
those

[[Page 72735]]

airplanes modified by cargo conversion STCs. The inspections mandated 
by the AASA should not be a substitute for routine maintenance. If 
maintenance is necessary at shorter intervals, the documentation of 
that maintenance will be a part of the records review.
Definitions
    Comments: Commenters state that the FAA should define the term 
``age-sensitive parts.'' According to the U.K. Civil Aviation Authority 
(CAA), other documents, such as AC 25.571-1C, ``Damage Tolerance and 
Fatigue Evaluation of Structure,'' and AC 91-MA, ``Continued 
Airworthiness of Older Small Transport and Commuter Airplanes; 
Establishment of Damage-Tolerance-Based Inspections and Procedures,'' 
and many aging initiatives do not define clearly the affected 
structural parts and the various sources of deterioration.
    In addition, commenters suggest that the FAA should define more 
clearly the difference between a ``minor'' and a ``major'' repair or 
structural alteration, for reporting purposes.
    FAA Response: The FAA interprets ``age-sensitive parts and 
components'' to mean, for the purpose of this rule, those parts and 
components of the primary structure of an airplane that are susceptible 
to fatigue or corrosion.
    Minor and major repairs, and structural alterations, are already 
defined in 14 CFR. Additional definitions would be beyond the scope of 
the AASA and are not addressed in this final rule.
Recordkeeping Requirements
    Summary of Proposal/Issue: The FAA proposes in Sec. Sec.  
121.368(d), 129.33(c), 135.422(d) and 135.422a(d) to require a 
certificate holder to make certain specific airplane records available 
to the Administrator for review. These records must contain the 
following information:
    [sbull] Total years in service of the airplane;
    [sbull] Total flight hours of the airframe;
    [sbull] Total flight cycles of the airframe (not required by Sec.  
135.422a(d));
    [sbull] Date of the last inspection and records review;
    [sbull] Current status of the life-limited parts of the airframe;
    [sbull] Time since the last overhaul of all structural components 
required to be overhauled on a specific time basis;
    [sbull] Current inspection status of the airplane, including the 
time since the last inspection required by the inspection program under 
which the airplane is maintained;
    [sbull] Current status (including the method of compliance) of ADs, 
the CPCP, and other inspections and procedures required;
    [sbull] A list of major structural alternations; and
    [sbull] A report of major structural repairs and the current 
inspection status of those repairs.
Current Recordkeeping Requirements
    Comments: Commenters note most of this information already is 
required to be maintained by operators under current regulations.
    The AIAA states proposed Sec.  121.368(d) duplicates the 
requirements of current Sec.  121.380. The AIAA further asserts that 
Sec.  121.380 is more comprehensive than proposed Sec.  121.368(d), 
particularly regarding ADs. Because most operators of large transport 
airplanes have developed elaborate maintenance recordkeeping 
requirements based on Sec.  121.380, the AIAA recommends the FAA revise 
proposed Sec.  121.368(d) to allow compliance with Sec.  121.380 as an 
alternative.
    FAA Response: Airplane records for air carriers operating under 
part 121 must be maintained under Sec.  121.380. Proposed Sec.  
121.368(d) requires retention of certain records that are not part of 
current Sec.  121.380 or Sec.  121.707, such as airframe flight cycles, 
total years in service of the airplane, damage-tolerance inspections, 
and date of last inspection records review. However, there is no 
restriction on operators using records maintained under current Sec.  
121.380 to comply with part of the requirements of Sec.  121.368.
Part 129 Recordkeeping Requirements
    Comments: One commenter states the FAA has never established 
definitive records and documentation requirements and that part 129 
operators use documents developed by ``listings companies'' and 
airplane owners. The commenter also notes there is no coordination of 
guidelines among the various FAA regions, and between ASIs and FAA 
headquarters. Additionally, the commenter notes most ``offshore'' 
operators maintain more complete and detailed records systems than U.S. 
operators; according to the commenter, a main area of weakness is 
centered around parts and assemblies that have been overhauled by U.S.-
based repair stations, which often fail to deliver proper records with 
parts.
    FAA Response: The FAA has established definitive recordkeeping 
requirements for persons operating aircraft under part 129. As a 
signatory to the Convention on International Civil Aviation, the United 
States requires each commercial operator of a U.S.-registered aircraft 
to maintain that aircraft in accordance with ICAO Annex 6, part I. 
Current Sec.  129.14 requires each air carrier and foreign person 
operating a U.S.-registered aircraft in common carriage to ensure each 
aircraft is maintained in accordance with a program approved by the 
Administrator. The FAA approves maintenance programs under Sec.  129.14 
that, at a minimum, comply with ICAO Annex 6, part I. Section 129.33 
requires records beyond those required by programs under current Sec.  
129.14.
    Annex 6, part I, Standard 8.8, Records, contains recordkeeping 
requirements, as follows:

    (1) 8.8.1. An operator shall ensure that the following records 
are kept:
    (a) In respect of the entire aeroplane: the total time in 
service;
    (b) In respect of the major components of the aeroplane:
    (1) The total time in service;
    (2) The date of the last overhaul;
    (3) The date of the last inspection;
    (c) In respect of those instruments and equipment, the 
serviceability and operating life of which are determined by their 
time in service;
    (1) Such records of the time in service as are necessary to 
determine their serviceability or to compute their operating life;
    (2) The date of the last inspection.
    (2) 8.8.1.1. These records shall be kept for a period of 90 days 
after the end of the operating life of the unit to which they refer.

Flight Cycles, Landings, and Total Years in Service
    Comments: Commenters state that current regulations do not require 
certificate holders to log flight cycles or landings; therefore, the 
FAA should specify that tracking this information is a new requirement. 
Also, the FAA should define ``flight cycle'' in 14 CFR 1.1 and develop 
guidelines for establishing a baseline number of airframe flight cycles 
if an operator has not been maintaining this information.
    In addition, commenters suggest that the FAA publish guidelines to 
be used in cases where a true determination of total years of service 
for an airplane is not possible.
    FAA Response: Under parts 121 and 129, operators track flight 
cycles to determine the current status of life-limited parts for each 
airframe, engine, propeller, and appliance. However, the FAA has 
revised the part 135 inspection and records review rules for airplanes 
initially certificated with nine or fewer passenger seats by 
eliminating the requirement to track total flight cycles on the 
airframe. The FAA has made this change to the rule because the 
inspection programs for these aircraft

[[Page 72736]]

may include service-history-based SSIPs instead of only damage-
tolerance-based inspections and procedures. In addition, operators 
should be able to determine the total number of years in service of an 
airplane subject to the rule. If the operator cannot determine the 
total number of years in service of an airplane, the FAA will rely on 
the date of manufacture of the airplane in question.

Designated Airworthiness Representatives

    Summary of Proposal/Issue: Because of the many airplanes that will 
have to be inspected over a short period of time and the anticipated 
growth of the aging fleet, the FAA proposed permitting DARs to 
accomplish the inspections and records reviews required by the rule. 
Proposed Sec.  183.33(a) expands the authority of DARs to permit them 
to make findings necessary to determine the continuing effectiveness of 
airworthiness certificates by conducting the inspections and records 
reviews required by Sec. Sec.  121.368, 129.33, 135.422, and 135.422a.
General
    Comments: Commenters generally oppose this provision. Several 
commenters, including the RAA, indicate the FAA is exceeding the intent 
of the AASA by delegating inspection authority and responsibility from 
the FAA to DARs.
    FAA Response: The FAA disagrees. The AASA requires the inspections 
and records reviews to be performed by the Administrator. There is, 
however, no statutory prohibition on the Administrator delegating the 
responsibilities specified under the AASA. A DAR is a designee of the 
FAA and a representative of the Administrator and, therefore, is 
qualified to accomplish the inspections and records reviews required by 
this final rule.
Qualifications of DARs
    Comments: Several commenters assert that delegating to DARs the 
responsibility of performing inspections and records reviews is a 
mistake, because DARs are not qualified to conduct the proposed 
inspections and records reviews. One commenter notes familiarity with 
the section of 14 CFR pertinent to records documentation and states 
that there has never been a requirement for a ``DAR certificate.''
    In addition, several commenters contend a PMI assigned to an 
operator or an operator's own quality control inspectors may be more 
qualified to conduct the proposed inspections and records reviews than 
either an ASI or a DAR not familiar with the operator. The RAA asserts 
requiring an ASI or DAR to conduct the inspections and records reviews 
is unprecedented and impractical, and would confuse the FAA's oversight 
responsibilities with that of an air carrier's responsibility for the 
airworthiness of its airplanes. Another commenter states the FAA should 
specifically and individually test and establish the capabilities of 
all DARs who are authorized to perform the inspections and reviews as 
stated in the proposal. Additionally, one commenter recommends that the 
FAA permit operator designees or Designated Engineering Representatives 
(DERs), in addition to DARs, to conduct the inspections and records 
reviews. Finally, one commenter states that under such a system, air 
carriers should make available to the FAA any and all records and 
findings necessary for the FAA to evaluate an airplane.
    FAA Response: While the AASA allows properly qualified persons to 
act on behalf of the FAA to conduct inspections and records reviews, 
the FAA acknowledges that many DARs currently may not be properly 
trained or qualified to conduct the required inspections and records 
reviews. The FAA will develop a training program and guidance material 
to enable DARs to properly accomplish the requirements of this rule. 
For this reason, initial inspections and records reviews are not 
required to be completed until a number of years after the effective 
date of the rule. After the FAA develops the training program and 
guidance material, ASIs and DARs will be trained and qualified to 
conduct the inspections and records reviews required by this rule.
    Regarding the commenter's reference to air carrier quality control 
inspectors, they are not representatives of the FAA and, therefore, 
would not be eligible to conduct the required inspections and records 
reviews under the AASA.
    However, an operator could facilitate the application of a member 
of its staff to become a DAR. There is an established procedure on how 
DARs are appointed, and the FAA does not foresee using a test to make 
this assessment. The FAA is unsure what the commenter means by the term 
``operator designees.'' However, DARs are the only designees allowed to 
conduct records reviews. Performing such reviews is not within the 
scope of a DER's delegation.
    In response to the commenter's assertion that there has never been 
a requirement for a ``DAR certificate,'' the FAA notes that a DAR is 
issued a Certificate of Authority and a Certificate of Designation in 
accordance with 14 CFR 183.13.
Lack of FAA Resources
    Comments: Many commenters question the FAA's assumptions about its 
ability to conduct inspections and records reviews. The ATA states its 
members are concerned that the ASI force, even augmented by DARs, would 
be insufficient to support the proposed inspections and reviews. 
According to ATA members, airlines currently find it difficult to hire 
qualified aircraft maintenance employees and predict a shortage in the 
near future of qualified ASIs and DARs. These members believe this 
situation would result in inexperienced ASIs and DARs conducting the 
inspections and reviews, and further delays in returning airplanes to 
service.
    FAA Response: The FAA disagrees. The FAA believes that there will 
be enough ASIs and DARs to accomplish needed inspections and records 
reviews and has therefore adopted a rule that permits the initial 
inspections and records reviews to be completed a number of years after 
the effective date of the rule. As previously stated, the FAA will 
train a group of inspectors and DARs to perform the inspections and 
records reviews required by this final rule and subsequently monitor 
the performance of those inspectors and DARs.

Supplemental Damage-Tolerance-Based Inspections and Procedures

    Summary of Proposal/Issue: Supplemental damage-tolerance-based 
inspections and procedures refer to an ``inspection program that 
specifies the procedures, thresholds, and repeat intervals that have 
been developed using damage tolerance principles.'' Damage-tolerance-
based inspections and procedures are developed by a type certificate 
holder or operator based on an engineering evaluation of likely sites 
where damage could occur, considering expected stress levels, material 
characteristics, and projected crack growth rates. The damage-
tolerance-based inspections and procedures specified in the proposal 
can be developed using one of the following methods:
    [sbull] Damage-tolerance-based inspections and procedures that 
comply with the damage tolerance provisions for metallic structure 
listed in 14 CFR 23.573, amendment 23-45, or subsequent amendments;
    [sbull] Damage-tolerance-based inspections and procedures that 
comply with 14 CFR 25.571, amendment 25-45, or subsequent amendments;

[[Page 72737]]

    [sbull] Advisory Circular (AC) 91-56, ``Supplemental Structural 
Inspection Program for Large Transport Category Airplanes,'' or AC 91-
56A, ``Continuing Structural Integrity Program for Large Transport 
Category Airplanes''; or
    [sbull] Any other method the Administrator finds complies with the 
principles of damage tolerance.
    Damage-tolerance-based inspections and procedures may be approved 
through an amended type certificate or STC process for airplanes 
certificated under a type certificate and associated amendments dated 
before those that require damage tolerance as part of airplane type 
design. Damage-tolerance-based inspections and procedures for certain 
older airplanes also may be approved by a Letter of Approval issued by 
the FAA Aircraft Certification Office (ACO) or office of the Small 
Airplane Directorate or Transport Airplane Directorate having 
cognizance over the type certificate for the affected airplane.
    Also, for some airplanes, the FAA has approved major structural 
modifications under an STC. The original type certificate holder may 
not have sufficient technical data pertinent to these modifications to 
assist the airplane operator in conducting a damage tolerance 
assessment of the modification. In these situations, the FAA expects 
the operator to work with the STC holder to develop damage-tolerance-
based inspections and procedures for that modification. If necessary, 
as an alternative, an operator may conduct its own damage tolerance 
assessments using competent engineering personnel, inspection findings 
from the current maintenance program, the airplane's design database, 
and model fleet experience.
General
    Comments: One operator asserts the proposal would result in the 
grounding of approximately 62 percent of the commuter fleet.
    FAA Response: The commenter has provided no data to substantiate 
its claim.
Alternatives to Damage Tolerance
    Comments: An Alaskan operator is not opposed to a SSIP that would 
be implemented in a cost-effective manner through incorporation into 
the operator's AAIP and developed by either the FAA or the 
``manufacturer.'' The commenter states the FAA and ``manufacturers'' 
have the competent engineering staff and access to the relevant design 
information, while the operators do not.
    The RAA notes the FAA fails to reference in the NPRM any technical 
basis for rejecting the alternative inspection program for smaller 
airplanes (submitted by the ARAC Small Transport/Commuter Airplane 
Airworthiness Assurance Working Group (SAAWG)). According to the RAA, 
damage tolerance analysis may be the most realistic analysis for 
certain principal structural elements but not necessarily all principal 
structural elements.
    FAA Response: The FAA appreciates the significant efforts of the 
SAAWG to explore alternative inspection programs for small- and 
commuter-sized aircraft. Based on the comments received, the FAA has 
changed the regulation to require damage-tolerance-based SSIPs for 
affected airplanes initially certificated with 10 or more passenger 
seats and service-history-based SSIPs for airplanes initially 
certificated with 9 or fewer passenger seats. Acceptable means of 
compliance for damage-tolerance-based SSIPs are contained in AC 91-56 
and AC 91-56A, and acceptable means of compliance for service-history-
based SSIPs are contained in AC 91-60. The FAA is requesting comments 
on draft AC 91-56B and AC 91-60A. Once these ACs become final, they too 
will be considered an acceptable means of compliance with this rule.
Nonmandated Supplemental Structural Inspection Programs
    Comments: The RAA states that proposed provisions to allow certain 
airplanes (with AD-mandated SSIPs) to operate until December 20, 2010, 
without damage tolerance programs discriminates against regional 
airplane operators with equivalent structural inspection programs not 
mandated by SSIP ADs.
    FAA Response: In this final rule, the FAA allows airplanes 
initially certificated with 9 or fewer passenger seats to have service-
history-based SSIPs that will be valid indefinitely. For those 
airplanes that were initially certificated with 10 or more passenger 
seats, the FAA expects damage-tolerance-based SSIPs for these aircraft 
to be completed within 4 years after the effective date of the rule. 
However, the FAA is delaying implementation of the requirement for 
damage-tolerance-based inspections with respect to those airplanes with 
AD-mandated non-damage-tolerance-based SSIPs until December 20, 2010.
Potentially Mandated Supplemental Structural Inspection Programs
    Comments: The RAA notes there may be airplane fleet types that are 
in the process of qualifying for an approved SSIP AD program but that 
may not be included in the final rule because the program was not 
complete at the time of publication of the NPRM. According to the RAA, 
several regional/commuter original equipment manufacturers (OEMs) 
report that they have submitted ``SIPs'' to the FAA as early as 1990, 
but the FAA has not adopted the ADs to mandate changes to the affected 
operators' maintenance programs.
    The RAA further asserts most airplanes with SSIPs are considerably 
older than the regional airplane types cited in the NPRM as having 
damage-tolerance-based ``maintenance inspection programs.'' Although 
the RAA appreciates the value of SSIPs, the RAA notes that the service 
experience for demonstrating structural integrity of the affected 
regional/commuter airplane types without SSIPs has been excellent.
    FAA Response: The commenter did not distinguish between damage-
tolerance-based SSIPs and service-history-based SSIPs. Those airplanes 
that have service-history-based SSIPs implemented through ADs will have 
until December 20, 2010, before they will have to comply with the 
damage tolerance requirements of this final rule. Those airplanes that 
do not have a service-history-based SSIP will have to comply with the 
damage tolerance requirements within 4 years after the effective date 
of this final rule.
Approval of Damage-Tolerance-Based Supplemental Structural Inspection 
Programs
    Comments: Regarding the FAA's proposal that airplane damage 
tolerance requirements may be approved through an amended or 
supplemental type certificate when necessary, one type certificate 
holder questions whether it is the FAA's intent to require type 
certificate holders to submit applications (FAA form 8110-12) for a 
type certificate amendment. If so, the type certificate holder warns 
that ACOs may become overwhelmed, which is a workload situation the FAA 
failed to consider in its cost-benefit analysis. The type certificate 
holder also questions whether it is the FAA's intent to modify the type 
certificate data sheet as a result of incremental changes to type 
design (as per the definition of an amended type certificate) or as the 
result of an STC.
    FAA Response: The FAA disagrees. The FAA understands that there are 
many ways to accomplish approved damage-tolerance-based or service-
history-based SSIPs, such as amended type certificates, STCs, letters 
of approval issued by the FAA, or service bulletins issued by the type 
certificate

[[Page 72738]]

holder and approved by the FAA. However, each operator is ultimately 
responsible for ensuring each of its airplanes has the appropriate 
inspection programs for the baseline airplane structure, which is the 
airplane structure as designed by the original type certificate holder, 
and each specific major repair, modification, and alteration to the 
baseline structure.
    Regarding the comment on FAA workload, the FAA has considered the 
effects of the rule on the FAA workload and has concluded that the 
workload will be within acceptable levels during the implementation 
period.
Letter of Approval
    Comments: The NPRM includes a provision that damage-tolerance-based 
inspections and procedures for certain older airplanes also may be 
approved by a letter of approval issued by the FAA. The type 
certificate holder questions whether this process is intended to 
address damage-tolerance-based inspections and procedures prepared by 
someone other than the type certificate holder. Also, the type 
certificate holder requests the FAA clarify whether the letter would be 
placed in the airworthiness limitations section of an airplane's 
maintenance manual, in the Airplane Flight Manual, in logbooks, or in 
another procedural manual.
    FAA Response: Inspection programs other than those developed by the 
airplane type certificate holder will be approved through a letter of 
approval by the FAA ACO or office of the Small Airplane Directorate or 
Transport Airplane Directorate responsible for that airplane's type 
certificate. The inspection programs required by this rule are for 
specific operations under part 121, 129, or 135 only and are to be 
added to the operator's maintenance or inspection program. Airplanes 
not being operated under the conditions specified in this rulemaking 
are not required to have these inspection programs. Adding such 
programs to the airworthiness limitations section of an airplane's 
maintenance manual is not appropriate because it would require that all 
operators comply with the program, not just those operators identified 
in this rulemaking.
Structural Assessment of Major Repairs, Alterations, and Modifications
    Comments: Transport Canada states the proposal is unclear about how 
an STC holder is required to support its designs as far as a structural 
assessment is concerned. Transport Canada notes major modifications/
alterations (including major repairs) may have resulted in a 
significant alteration to the design, affecting the usage spectrum 
associated with the STC. According to the commenter, this may result in 
an undue burden on the operator who may need to perform a damage-
tolerance-based assessment without assistance from the type certificate 
holder. Transport Canada states it is inappropriate to require a type 
certificate holder to provide assistance in such cases. Transport 
Canada recommends the FAA provide procedures to allow an operator to 
implement a supplemental integrity program for its airplanes when the 
type certificate holder is not able to do so because of an STC or major 
repair.
    FAA Response: This rulemaking states that no operator may operate 
an airplane after 4 years after the effective date of the rule unless 
the maintenance or inspection program for that airplane includes 
damage-tolerance-based or service-history-based SSIPs, as applicable. 
This program applies to the baseline structure of the airplane, which 
is that structure designed by the original type certificate holder, as 
well as any existing or future major repairs, major alterations, or 
modifications. The exceptions to the 4-year requirement are listed in 
Sec. Sec.  121.370a, 129.16, and 135.168.
    Modifications to the baseline structure can be accomplished by an 
STC or by the type certificate holder who has certificated a major type 
design change. The preamble to the NPRM states that the operators 
should work with STC holders and type certificate holders to accomplish 
a damage tolerance assessment of the modified structure, but in the 
event that the STC holder or type certificate holder is not able or 
willing to help the operator, then the operator will be responsible for 
accomplishing the damage tolerance assessment. As stated in the 
preamble to the NPRM, the operator may (1) accomplish the assessment if 
it has the capability or (2) contract the appropriate persons to 
accomplish the assessment. The FAA recognizes that this may be a burden 
on the operator, but the AASA requires the Administrator to ensure the 
continuing airworthiness of aging airplanes. The FAA has determined 
that damage-tolerance-based and service-history-based SSIPs are the 
best way to achieve that goal.
    The FAA also has revised AC 91-56A, which provides detailed 
guidance to type certificate holders and operators regarding the 
accomplishment of damage tolerance assessments of repaired, altered, or 
modified structures.
Compliance Alternatives
    Comments: Commenters recommend various alternatives to the proposed 
regulations on damage-tolerance-based SSIPs. The ATA states 
incorporation of mandated programs, including ``supplemental structural 
inspection document programs,'' CPCPs, repair assessment programs, and 
compliance with air carrier maintenance programs, provides the means 
necessary to comply with the proposed rule. Other commenters agree with 
the ATA's position.
    FAA Response: The FAA agrees in part and has revised the rule to 
permit the use of service-history-based SSIPS for certain aircraft. The 
programs the commenters describe only satisfy part of the requirements 
of this final rule. SSIPs only address certain portions of an 
airplane's structure while the damage-tolerance-based or service-
history-based SSIPs specified by this rule address the entire primary 
structure of an airplane, including the baseline structure, and major 
repairs, major alterations, and modifications to baseline structure.
    The ``Repair Assessment for Pressurized Fuselages'' final rule (65 
FR 24108, April 25, 2000) established new Sec. Sec.  121.370 and 
129.32. These sections require a repair assessment program for many of 
the airplanes also affected by this final rule. These include the 
Airbus A300, excluding the -600 series; Boeing 707, 720, 727, 737, and 
747; BAe BAC 1-11; Fokker F28; and Lockheed L-1011; and McDonnell 
Douglas DC-8, DC-9/MD-80, and DC-10. However, Sec. Sec.  121.370 and 
129.32 address only fuselage pressure boundary repairs (fuselage skin, 
door skin, and bulkhead webs).
    Meeting the requirements of Sec. Sec.  121.370 and 129.32 is an 
acceptable means of compliance with this final rule to the extent that 
these requirements address repairs to the fuselage pressure boundary 
for the above-noted airplanes. Operators will have to accomplish 
additional work to fully comply with this rule. They must establish 
damage-tolerance-based SSIPs or service-history-based SSIPs, as 
applicable, for major repairs, major alterations, and modifications to 
structures not affected by the repair assessment program, such as 
fuselage frames and longerons, and wing and empennage structures.
Alternatives to Damage-Tolerance-Based Supplemental Structural 
Inspection Programs
    Comments: One foreign aircraft type certificate holder states that 
the 3- to 10-year compliance thresholds in the NPRM require further 
detail regarding

[[Page 72739]]

the intended program before they can be implemented. The type 
certificate holder specifically would like the FAA to further discuss 
alternate means of complying with this proposed rule. An FAA-approved 
repair station specializing in the major repair, alteration, and heavy 
maintenance of deHavilland DHC-6 airplanes also states the required 
implementation of existing proven type certificate holder inspections 
and procedures is a more appropriate response to the airworthiness 
concerns presented by the FAA than the implementation of new, costly 
programs. Although the commenter admits damage-tolerance-based 
``inspections and procedures'' may prove useful in the successful 
maintenance of DHC-6 airplanes, the commenter states that current safe-
life-based component replacement requirements and inspections have 
proven successful for over 30 years and should be retained.
    The GAMA asserts that a regime of replacing components and parts 
when they reach their design service lives is one way to ensure 
structural integrity. Other commenters support the GAMA position, 
noting a damage-tolerance-based SSIP alone is too restrictive. 
According to the GAMA, these regimes should be appropriate for 
particular structural configurations and should employ a schedule of 
supplemental inspections, as necessary. The GAMA states reliance on 
frequent, repetitive inspection under a damage-tolerance-based approach 
would allow for greater human error. Additionally, the GAMA disagrees 
with the FAA's implied requirement that ``manufacturers'' must be 
responsible for developing or assisting operators in the development of 
damage-tolerance-based inspections and procedures. Also, the GAMA notes 
several ``manufacturers'' already have developed and made available 
appropriate structural integrity inspection programs.
    Transport Canada agrees with the GAMA position and states a 
structural integrity inspection program must include mandatory 
component replacement (safe life), as well as a mandatory inspection 
program with a CPCP to ensure the fatigue inspections and part 
replacement remains valid. According to Transport Canada, including a 
component replacement (safe life) program is important for the 
following reasons:
    [sbull] A safe life program may be required to avoid the risks 
associated with structural degradation caused by a form of widespread 
fatigue damage known as multiple site damage (MSD). According to 
Transport Canada, failure to detect MSD exposes an airframe to a risk 
of sudden crack coalescence, possibly leading to total structural 
failure without adequate warning. To ensure structural integrity, 
Transport Canada asserts a structure that is at risk for MSD must be 
replaced or repaired at the appropriate interval. According to 
Transport Canada, an inspection program may not alleviate the risk that 
there may be cracks too small to be detected reliably. Transport Canada 
lists several methodologies, including fracture mechanics (crack-
growth) techniques and tear-down techniques, that could be used to 
determine the appropriate component/part replacement (safe life) 
interval.
    [sbull] For aging airplanes, particularly in the small commuter 
class (for example, CAR 3 aircraft, 14 CFR part 23 aircraft, and SFAR 
41 aircraft), component design was not influenced by damage tolerance 
inspection principles. As such, it may be impractical, in an 
airworthiness sense, to apply the damage tolerance requirements in a 
retroactive manner. Transport Canada notes the designers of these 
airplanes may not have considered the inspectability of their designs 
and may have designed components to be replaced to ensure structural 
integrity.
    The Civil Aviation Safety Authority of Australia (CASA) supports 
damage-tolerance-based inspections and procedures and recommends 
changing the phrase `` * * * unless the maintenance program for that 
airplane includes damage-tolerance-based inspections and procedures'' 
to `` * * * unless the maintenance program for that airplane includes 
inspections or other procedures developed in accordance with Sec. Sec.  
23.571 to 23.574, or Sec.  25.571, as applicable'' for the following 
reasons:
    [sbull] Consistency with the design rules--While operational rules 
may match current design rules, they should not exceed them as proposed 
in the NPRM, because the NPRM is more restrictive. Part 23 allows three 
fatigue control options while the NPRM allows only damage-tolerance-
based inspections.
    [sbull] To allow more than one method of analysis--For light 
airplanes, this change would allow a conventional fatigue evaluation as 
well as a crack-growth analysis to determine inspection thresholds and 
life limits for all structures, not just fail-safe structures.
    [sbull] To allow more than one method of control--There are two 
ways to control fatigue: safety by inspection and safety by retirement. 
Neither method is superior and each has its place. Retirement is a 
practical alternative to inspection and Australian operators routinely 
replace wing spar lower caps on small twin-engine airplanes. This 
procedure costs less than an engine overhaul and is required less 
often. Often operators choose to replace rather than inspect. The CASA 
suggests the FAA allow and promote replacement and modification in 
accordance with its policy to avoid relying on continuing inspection 
for in-service cracking.
    [sbull] To reduce the cost of compliance--Consistency with the 
design rules would allow immediate acceptance of airplanes whose 
maintenance programs have already complied with the part 23 fatigue 
rules in Australia, the United Kingdom, and (to a lesser extent) the 
United States.
    [sbull] To avoid duplication in regulations and guidance material.
    FAA Response: The FAA notes that the method of compliance with the 
rule is currently outlined in AC 91-56A and AC 91-60. The FAA is 
requesting comments on draft AC 91-56B and AC 91-60A. Once these ACs 
become final, they too will be considered an acceptable means of 
compliance with this rule. For each airplane initially certificated 
with 10 or more passenger seats, the inspection program will be based 
on damage tolerance. Many of the new regional commuter airplanes have 
already been certificated to damage tolerance requirements.
    Operators are ultimately responsible for ensuring a damage-
tolerance-based SSIP is developed for airplanes initially certificated 
with 10 or more passenger seats. The FAA encourages airplane type 
certificate holders to participate in this development. Even if certain 
airplanes were not initially certificated to a damage tolerance 
requirement, completing a damage-tolerance-based SSIP is still possible 
on the airplanes' structures.
    In response to the CASA comments, the FAA has deliberately made 
changes to parts 121, 129, and 135 to address the continuing 
airworthiness of aging airplanes. This method of compliance is 
consistent with the AASA. The CASA's comment with reference to the 
certification requirements of part 23 are appropriately noted, but any 
changes to part 23 would only affect new designs. Procedures on how to 
develop a damage-tolerance-based SSIP are described in AC 91-56A.
    As discussed earlier in this final rule, the FAA requires a 
service-history-based SSIP for airplanes initially certificated with 9 
or fewer passenger seats, but retains the proposed requirement of 
damage-tolerance-based SSIPs for airplanes initially certificated with 
10 or more passenger seats.

[[Page 72740]]

Mandating Damage-Tolerance-Based Supplemental Structural Inspection 
Programs Through Airworthiness Directives
    Comments: Several commenters state that the implementation of 
damage-tolerance-based SSIPs on any additional airplane types should be 
addressed in ADs for those airplane types.
    FAA Response: The FAA disagrees. The inspection programs required 
by this rule are for specific operations under part 121, 129, or 135 
only and are to be added to the operator's maintenance or inspection 
program. Adding such programs through an AD would require that all 
operators comply, not just those operators identified in this 
rulemaking. The damage-tolerance-based SSIP must still be approved by 
the FAA ACO or office of the Small Airplane Directorate or Transport 
Airplane Directorate responsible for each affected airplane's type 
certificate and the final rule has been revised to reflect this 
approval requirement.
Damage-Tolerance-Based Supplemental Structural Inspection Programs for 
Small Transport Airplanes
    Comments: According to the ADOT&PF, a damage-tolerance-based 
``inspection program'' is not an appropriate inspection program for 
smaller airplanes and components that were not designed to have damage-
tolerance-based inspections. Many smaller transport category airplanes 
are not manufactured to enable applicable components to be reconfigured 
for damage-tolerance-based inspections. The commenter believes real-
world experience is a better indicator of mechanical failure; neither 
accident records nor Structural Difficulty Reports support a mandatory 
damage-tolerance-based ``program'' for smaller airplanes.
    Also, the ADOT&PF notes that developing a damage-tolerance-based 
``inspection program'' requires engineering data for the affected 
components. These data are not available for most airframes and 
components; therefore, each user of each type of airframe would be 
required to reverse engineer the components at great expense. According 
to the commenter, the only cost-effective way to establish a damage-
tolerance-based ``inspection program'' is for the FAA or the 
``manufacturer'' to develop such a program for only those airframe 
components compatible with such a retrofit program and to make the data 
available to users.
    The commenter further states retrofitting damage-tolerance-based 
``programs'' may introduce risks to continued airworthiness caused by 
inspection access issues; that is, inspecting can result in maintenance 
problems. Additionally, the commenter notes that operators of aging 
airplanes eventually phase out older airplanes because the maintenance 
costs for these airplanes increase as the airplane ages; therefore, 
focusing on aging airplane inspection may not be necessary.
    FAA Response: In this final rule, the FAA requires a service-
history-based SSIP for airplanes initially certificated with 9 or fewer 
passenger seats, but retains the proposed damage-tolerance-based SSIPs 
for airplanes initially certificated with 10 or more passenger seats.
Applicability to Large Transport Category Airplanes
    Comments: One commenter states proposed Sec.  121.370a(a) could be 
misinterpreted to apply equally to large transport category airplanes. 
To eliminate confusion, the commenter recommends the FAA alter this 
paragraph to read as follows:

    Except as otherwise provided in this section, no certificate 
holder may operate an airplane listed in appendix [N] under this 
part after [insert date 4 years after the effective date of the 
rule] unless the maintenance program for that airplane includes 
damage-tolerance-based inspections and procedures.

    FAA Response: The FAA disagrees. Except for airplanes operated by a 
certificate holder between any point in Alaska and another point in 
Alaska, Sec.  121.370a is applicable to all airplanes that operate 
under part 121, including large transport category airplanes.
Part 121 Proposed Changes
    Comments: The RAA recommends the FAA remove all part 121 provisions 
in the NPRM. The RAA asks that the FAA replace them with the 
requirement that each certificate holder incorporate into its 
maintenance program either a damage-tolerance-based inspection program 
or a structural integrity inspection program for each airplane operated 
by that certificate holder. The inspection program should require 
approval by the FAA ACO having cognizance over the type certificate for 
the affected airplane. According to the RAA, compliance should be 
required under the guidelines specified in proposed Sec.  121.368(b).
    The GAMA recommends the FAA revise Sec.  121.370a(a), (b), and (c) 
by allowing the use of an FAA-approved structural integrity inspection 
program based on fatigue analysis and fatigue tests, in addition to the 
proposed damage-tolerance-based SSIP.
    Transport Canada recommends the FAA revise Sec.  121.370a to 
include and explicitly state that component replacement (safe life) 
programs are acceptable as a means of ensuring continued structural 
integrity as an airframe ages.
    FAA Response: The FAA disagrees. All airplanes operating under part 
121 must have a maintenance program based on damage tolerance 
regardless of the passenger seating capacity. Many of those airplanes 
were designed with multiple load path fail-safe or multiple load path 
crack-arrest design features; therefore, the inspection thresholds can 
be based on a conventional fatigue analysis and tests with an 
appropriate scatter factor based on AC 25.571-1C.
Compliance Timeframe for Establishing Damage-Tolerance-Based 
Supplemental Structural Inspection Programs
    Comments: According to the ATA, the requirement in proposed Sec.  
121.370a(a) to establish a damage-tolerance-based ``inspection 
program'' within 4 years of the effective date of the rule is 
unreasonable because damage-tolerance-based ``inspections'' usually are 
imposed at a cycle threshold greater than 75 percent of the design-life 
goal. For example, an anomalous result of the proposal would be for a 
Boeing 737-800. The Boeing 737-800 is not fully damage tolerance 
designed and would be required to have a complete SSID within 4 years 
even though it has been in service only 2 years. The paragraph should 
be limited to airplanes that do not otherwise have FAA-mandated aging 
programs, or it could state that such airplanes already meet the 
paragraph's requirements. One foreign aircraft type certificate holder 
asks the FAA to reconsider the proposed compliance dates for affected 
airplanes in proposed Sec.  121.370a.
    FAA Response: The FAA disagrees. For any airplane certificated 
before the effective date of the rule, the operators must have a 
damage-tolerance-based SSIP in place within 4 years from the effective 
date of the rule. For an airplane certificated after the effective date 
of the rule by an amended type certificate that preceded Amendment 25-
45 (43 FR 46238 published in 1978), the FAA has revised Sec. Sec.  
121.370a and 129.16 to allow operators to have a damage-tolerance-based 
SSIP in place within 4 years of the date of the amended type 
certification. Although this rule specifies dates when a damage-
tolerance-based SSIP will be required, the actual inspection thresholds 
may occur much later. The FAA believes the times specified in this 
final rule are adequate.

[[Page 72741]]

Proposed Changes to Sec. Sec.  121.135 and 121.369
    Comments: One operator states that Sec.  121.135, Manual content, 
and/or Sec.  121.369, Manual requirements, can be revised to include 
the proposed Sec.  121.370a damage-tolerance-based ``inspection 
requirements.''
    FAA Response: The FAA disagrees. The requirement for a damage-
tolerance-based SSIP is independent of any requirement for inclusion in 
an operator's manual. It has been added to Sec.  121.370a to keep all 
the requirements for aging airplane supplemental inspections in part 
121 in one section.
Part 129 Proposed Changes
    Comments: The RAA recommends the FAA remove all part 129 provisions 
in the NPRM. The RAA asks that the FAA replace them with the 
requirement that each certificate holder incorporate into its 
maintenance program either a damage-tolerance-based ``inspection 
program'' or a structural integrity inspection program for each 
airplane operated by that certificate holder. The inspection program 
should require approval by the FAA ACO having cognizance over the type 
certificate for the affected airplane. According to the RAA, compliance 
should be required under the guidelines specified in proposed Sec.  
129.33(b).
    The GAMA recommends that the FAA revise Sec.  129.16(a), (b), (c), 
and (d) by allowing the use of an FAA-approved structural integrity 
inspection program based on fatigue analysis and fatigue tests, in 
addition to a proposed damage-tolerance-based ``inspection program.'' 
Additionally, the GAMA notes that the preamble to the NPRM refers to 
requiring damage-tolerance-based ``inspections and procedures'' earlier 
than December 20, 2010, for airplanes with nine or fewer passenger 
seats operated under part 129. The GAMA states that the preamble does 
not properly reflect the proposed requirement in Sec.  129.16(b).
    Transport Canada recommends the FAA revise Sec.  129.16 to include 
and explicitly state that component replacement (safe life) programs 
are acceptable as a means of ensuring continued structural integrity as 
an airframe ages.
    FAA Response: In this final rule, the FAA requires a service-
history-based SSIP for airplanes initially certificated with 9 or fewer 
passenger seats, but retains the proposed damage-tolerance-based SSIPs 
for airplanes initially certificated with 10 or more passenger seats.
    A large number of airplanes operating in part 129 were designed 
with multiple load path fail-safe or multiple load path crack-arrest 
design features; therefore, the inspection thresholds can be based on a 
conventional fatigue analysis and tests with an appropriate scatter 
factor based on AC 25.571-1C.
    Airplanes initially certificated with nine or fewer passenger seats 
will not require a service-history-based SSIP until December 20, 2010, 
unless the airplane is listed in appendix B to part 129. For those 
airplanes, a schedule based on the design-life goal is shown in Sec.  
129.16(d).
Section 129.16(a)
    Comments: One commenter states proposed Sec.  129.16(a) could be 
misinterpreted to apply equally to large transport category airplanes. 
Similar to its comment regarding Sec.  121.370a, the commenter 
recommends the FAA reference appendix B to part 129 in Sec.  129.16(a).
    FAA Response: The FAA disagrees. Section 129.16(a) is applicable to 
all U.S.-registered multiengine airplanes that operate under part 129, 
which includes large transport category airplanes.
    The FAA proposed to revise Sec.  129.1(b) to specify the 
applicability of the aging airplane requirements to some operations 
conducted under part 129. In this regard, the FAA inadvertently failed 
to cite Sec.  129.32 and proposed Sec.  129.33 in proposed Sec.  
129.1(b). This final rule corrects that omission.
    In addition, the FAA has revised the rest of Sec.  129.1 to make it 
easier to read. The paragraph (a) reference to the ``exception'' in 
paragraph (b) was not accurate, because the requirements referenced in 
paragraph (b) add to those in paragraph (a), as opposed to conflicting 
with them. Thus, the FAA has deleted from paragraph (a) ``except as 
provided in paragraph (b) of this section.'' The FAA has added headings 
to paragraphs (a) and (b), and has placed the definition of ``foreign 
person'' and ``years in service'' in a new paragraph (c). Paragraph (b) 
now specifically includes the applicability of Sec. Sec.  129.14, 
129.16, 129.20, 129.32, and 129.33 to operations of U.S.-registered 
aircraft operated solely outside the United States in common carriage 
by a foreign person or foreign air carrier.
    The FAA has not made any substantive changes to part 129, other 
than adding the aging airplane requirements and specifying that the 
requirements would only apply to U.S. multiengine airplanes operated 
under the part.
Part 135 Proposed Changes
    Comments: The RAA recommends the FAA remove all part 135 provisions 
in the NPRM. The RAA asks that the FAA replace them with the 
requirement that each certificate holder incorporate into its 
maintenance program either a damage-tolerance-based ``inspection 
program'' or a structural integrity inspection program for each 
airplane operated by that certificate holder. The inspection program 
should require approval by the FAA ACO having cognizance over the type 
certificate for the affected airplane. According to the RAA, compliance 
should be required under the guidelines specified in proposed Sec.  
135.422(b).
    The GAMA recommends the FAA revise Sec.  135.168(a), (b), (c), and 
(d) by allowing for use of an FAA-approved structural integrity 
inspection program based on fatigue analysis and fatigue tests, in 
addition to a proposed damage-tolerance-based ``inspection program.'' 
Additionally, the GAMA notes the preamble to the NPRM refers to 
requiring damage-tolerance-based ``inspections and procedures'' sooner 
than December 20, 2010, for airplanes with nine or fewer passenger 
seats operated under part 135. The GAMA states the preamble does not 
properly reflect the proposed requirement in Sec.  135.168(b).
    Transport Canada recommends the FAA revise Sec.  135.168 to include 
and explicitly state that component replacement (safe life) programs 
are acceptable as a means of ensuring continued structural integrity as 
an airframe ages.
    Although generally supportive of the proposal, the CASA is 
concerned about the practicalities and details of the proposed rule, 
particularly for light airplanes operating under part 135.
    The U.K. CAA notes that the NPRM states that it ``does not propose 
requirements for on-demand passenger or cargo carrying operations under 
part 135.'' However, the NPRM does introduce a new Sec.  135.168. The 
CAA questions how the distinction would be made so that on-demand 
operations are exempt from the rule.
    FAA Response: The FAA disagrees. In response to the U.K. CAA's 
comment, this rule is applicable to operators conducting scheduled 
operations as defined in Sec.  119.3. The three requirements for 
scheduled operations include: five round trips per week, one route 
between two or more points, and the publication of a schedule. On-
demand or cargo-only operations conducted under part 135 are not 
affected by this rule.

[[Page 72742]]

    In this final rule, the FAA requires a service-history-based SSIP 
for airplanes initially certificated with 9 or fewer passenger seats, 
but retains the proposed damage-tolerance-based SSIPs for airplanes 
initially certificated with 10 or more passenger seats.

Proposed Appendixes

    Summary of Proposal/Issue: To assist in implementing the proposed 
rule, the FAA included appendixes that list the FAA-established design-
life goals of several airplane types commonly used in scheduled 
service. Proposed appendix N to part 121 lists the airplanes and 
design-life goals referenced in proposed Sec.  121.370a. Proposed 
appendix B to part 129 lists the airplanes and design-life goals 
referenced in proposed Sec.  129.16. Proposed appendix G to part 135 
lists the airplanes and design-life goals referenced in proposed Sec.  
135.168.
General
    Comments: The RAA states the proposed appendixes would conflict 
with other FAA-approved certification documents unless they are updated 
continually. The RAA notes several of the design-life goals provided 
are inaccurate and, once adopted, would require constant revision. 
According to the RAA, several foreign-based airframe OEMs contend that 
the proposed fatigue lives for their fleet types are inaccurate and 
that extensions have been approved by foreign regulatory authorities. 
Also, the RAA states the design-life goals do not account for the 
differences in design-life goals that exist between the various 
airplane structures (for example, wings, fuselage, and vertical and 
horizontal stabilizers).
    FAA Response: This rulemaking action is intended to ensure the 
continued airworthiness of the affected airplanes by requiring SSIPs 
based on damage tolerance or service history. In response to the RAA's 
comment, the FAA has published the design-life goals of certain 
airplanes in the appendixes of the final rule to provide a quick 
reference to operators. The FAA has not imposed any new requirements 
through these appendixes. However, as a result of comments received, 
the FAA has corrected the appendixes to reflect current FAA-approved 
design-life goals. The FAA has no intention to further delay 
implementation of the damage-tolerance-based SSIPs.
    For airplanes initially certificated with nine or fewer passenger 
seats, the FAA originally proposed an inspection program that includes 
damage-tolerance-based SSIPs. In response to the comments received, 
this final rule adds an exception for multiengine airplanes initially 
certificated with nine or fewer passenger seats and conducting 
scheduled operations under part 129 or part 135. Those airplanes can 
have a service-history-based SSIP instead of a damage-tolerance-based 
SSIP.
    Airplanes operating under part 121 must have damage-tolerance-based 
SSIPs 4 years after the effective date of the rule. For those airplanes 
listed in the appendix, from 4 years after the effective date of the 
rule, the certificate holder may operate that airplane until the date 
the airplane's time in service reaches the design-life goal or until 
December 20, 2010, whichever occurs sooner. As noted in the preamble to 
the proposal, the design-life goals listed are a result of information 
from the type certificate holder, the airworthiness authorities of 
other countries, or the FAA.
Appendix N to Part 121
    Comments: Commenters provide specific comments regarding proposed 
appendix N to part 121. The RAA states that the information provided in 
appendix N to part 121 can be obtained from other sources and is 
therefore redundant. Another commenter believes the FAA should include 
in appendix N any airplane that has design-life goals established for 
flight cycles and afford them the same opportunities to develop 
``SIPs'' based on these goals. According to the commenter, the FAA also 
should consider providing another appendix to part 121 listing those 
airplanes that have existing FAA-approved ``SIPs'' that meet the 
proposed requirements.
    FAA Response: The FAA disagrees. Appendix N is necessary to 
determine when damage-tolerance-based SSIPs are required for airplanes 
with design-life goals; appendix N lists those design-life goals. The 
rest of the airplanes operating under part 121 must comply within 4 
years after the effective date of the rule.
    The FAA did not want to provide another appendix to part 121 
because a list of SSIPs mandated through specific ADs may have to be 
revised. If these ADs were listed in such an appendix, the FAA would 
have to revise the appendix through rulemaking action each time a SSIP 
was changed.
Appendix B to Part 129
    Comments: Regarding proposed appendix B to part 129, the RAA states 
the information provided in the appendix can be obtained from other 
sources and is therefore redundant.
    FAA Response: Appendix B is necessary to determine when damage-
tolerance-based SSIPs are required for airplanes with design-life 
goals.
Appendix G to Part 135
    Comments: Regarding proposed appendix G to part 135, the RAA states 
the information provided in appendix G can be obtained from other 
sources and is therefore redundant.
    Another commenter operating in Alaska states there is no technical 
basis for including some airplanes in appendix G and not others. The 
commenter cites the example of the Piper Seneca, which could operate 
until 2010 without a ``SIP'' even though it may be older and have 
``higher time'' than a Piper PA31-350 that would have to comply 6 years 
earlier. This results in arbitrary and capricious rules. Operators who 
are fortunate, whose airplanes were the subject of ``non-damage-
tolerance-based ADs'' before the rule change, also could operate until 
2010.
    According to the commenter, the FAA should consider allowing all 
nonpressurized airplanes of nine or fewer passenger seats to operate 
without a ``SIP'' until 2010 and reevaluate these airplanes based on 
the experience with larger pressurized airplanes. The NPRM is not clear 
about whether compliance would be delayed for airplanes with nine or 
fewer passenger seats. Such a change would dramatically reduce the 
burden to small businesses and would be a negligible change to the 
rule.
    FAA Response: The FAA agrees in part. Appendix G is necessary to 
determine when damage-tolerance-based or service-history-based SSIPs 
are required for airplanes with design-life goals.
    In response to the commenter's suggestion that the FAA delay 
compliance with this final rule for airplanes initially certificated 
with nine or fewer passenger seats, the FAA agrees and has amended 
proposed Sec.  135.168 to reflect this change.
BAe Jetstream Model 3101 or 3201
    Comments: British Aerospace (Operations) Limited states that the 
design-life goals listed in this proposal for the Jetstream 3101 and 
3201 do not represent current figures published in approved aircraft 
maintenance documentation. The commenter indicates that the U.K. CAA 
approved revised figures in 1997. According to the commenter, the 
revised Jetstream 3101 lives of the components of the airframe are as 
follows: (1) 45,750 landings for the wing, (2) 46,200 landings for the 
fuselage, (3) 60,360 landings for the vertical stabilizer, and (4) 
45,000 landings for the horizontal stabilizer. The revised Jetstream 
3201 lives of the components of the airframe are as follows: (1) 30,000 
landings for the

[[Page 72743]]

wing, (2) 46,200 landings for the fuselage, (3) 55,500 landings for the 
vertical stabilizer, and (4) 40,000 landings for the horizontal 
stabilizer.
    FAA Response: The FAA agrees. Using correlation between flight 
hours and landings specified in notice no. 99-02, the FAA has revised 
appendix N to part 121, appendix B to part 129, and appendix G to part 
135 to reflect the new design-life goals for the Jetstream 3101. The 
Jetstream 3201's design-life goal remains at 30,000 hours.
Beech 1900 (Any Model)
    Comments: The Raytheon Aircraft Company (Raytheon) states the wings 
on Beech 1900 aircraft use a damage tolerance approach based on test 
data to define an inspection program. The fuselage uses a fail-safe 
approach based on test data to define an inspection program. Also, the 
empennage currently is a safe-life item based on analysis only. 
Raytheon recommends the FAA include this information in the proposal.
    FAA Response: The FAA recognizes that Beechcraft uses a damage 
tolerance approach based on test data to define an inspection program 
for the Beech 1900 wings. The FAA also recognizes that the fuselage 
uses test data to define an inspection program, and the empennage is a 
safe-life item based on analysis only.
    The FAA finds that an inspection program based solely on test data 
is not consistent with the requirements of the final rule. A damage-
tolerance-based SSIP still needs to be developed for the Beech 1900 
within the timeframes listed in this rulemaking.
Beech 300, 300LW, B300, or B300C
    Comments: Raytheon states the wings on these airplanes use a damage 
tolerance approach based on test data to define an inspection program.
    The fuselage uses a fail-safe approach based on test data to define 
an inspection program. Also, the empennage currently is a safe life 
item based on analysis only. Raytheon recommends the FAA include this 
information in the final rule.
    FAA Response: The FAA recognizes that Raytheon uses a damage 
tolerance approach based on test data to define an inspection program 
for the Beech 300 empennage. The FAA also recognizes that the fuselage 
uses test data to define an inspection program.
    The FAA finds that a SSIP based solely on test data is not 
consistent with the requirements of the final rule. A damage-tolerance-
based SSIP still needs to be developed for the Beech 300 within the 
timeframes listed in this rulemaking.
Beech 99 (Any Model)
    Comments: Raytheon recommends the FAA note in the proposal that 
currently there is a Continued Airworthiness Program in place for Beech 
99 models, based on full-scale tests and field experience. According to 
Raytheon, this program details inspections of all major components: 
wing, fuselage, and empennage. Raytheon states the current 46,000-hour 
life limit is based on analysis supported by test data.
    FAA Response: The FAA acknowledges that Raytheon has a continued 
airworthiness program in place for the Beech 99 models based on full-
scale tests and field experience. The FAA also acknowledges that the 
current 46,000 hour limit is based on analysis supported by test data.
    The FAA finds that an inspection program based solely on test data 
is not consistent with the requirements of the final rule. A damage-
tolerance-based SSIP still needs to be developed for all Beech 99 
models within the timeframes listed in this rulemaking.
Cessna 402
    Comments: One operator states that DOT/FAA/AR-98/66 
(Supplementation Inspection Document Development Program for the Cessna 
Model 402) and Cessna Aircraft Company Structures Report No. S-402-76-2 
(Model No. 402) do not support design-life goals for the Cessna 402C 
(7,700 hours for the wing structure was cited in the proposal). The 
commenter notes all tests were conducted in accordance with fail-safe 
requirements in Sec.  23.572, Metallic wing, empennage, and associated 
structures.
    An Alaskan operator states that AD 79-10-15, ``Cracks in Wing 
Structure,'' on the Cessna 402 has been very successful in addressing 
aging airplane concerns. However, while the NPRM proposes inspections 
every 5,000 hours, the AD requires inspections every 400 hours. This 
demonstrates that the ``one-size-fits-all'' approach does not address 
the safety needs of aging airplanes. According to the commenter, 
inspection of such a critical primary structure can and should be 
undertaken much more frequently than every 5,000 hours, especially for 
airplanes with fewer than 10 seats. For example, the commenter's fleet 
of Chieftains operates under an approved airworthiness inspection 
program that ensures all critical structures are inspected every 360 
hours.
    FAA Response: The FAA is requiring service-history-based SSIPs for 
each multiengine airplane initially certificated with nine or fewer 
passenger seats. However, Cessna has developed a damage-tolerance-based 
SSIP, and the FAA strongly encourages operators to incorporate this 
program into their existing inspection programs.
    The Cessna-developed damage-tolerance-based SSIP provides 
sufficient continuing airworthiness information to meet the intent of a 
service-history-based SSIP and can be used to comply with that 
requirement.
    The FAA has corrected the design-life goal for the Cessna 402 in 
appendix B to part 129 to 7,700 hours, which is based on the design-
life goals established by U.K. and Australian airworthiness 
authorities. With respect to the commenter's reference to a 5,000-hour 
repetitive inspection interval number, it is unclear where the 
commenter obtained this number, which is not applicable to the Cessna 
402 SID program.
    This final rule includes the requirement for service-history-based 
SSIPs for airplanes initially certificated with nine or fewer passenger 
seats. Guidance for complying with a service-history-based SSIP will be 
provided in an AC. The FAA is requesting comments on draft AC 91-56B 
and AC 91-60A. Once these ACs become final, they too will be considered 
an acceptable means of compliance with this rule. Based on service 
experience, different inspection thresholds and intervals may be 
required for different aircraft models.
deHavilland DHC-6 (Any Model)
    Comments: Bombardier Aerospace (Bombardier) notes that the 
deHavilland DHC-6 Series 300 originally was certificated with a 66,000-
hour safe life with a one-time wing replacement mandated at 33,000 
hours. However, Bombardier and Transport Canada concluded in 1996 that 
continued operation of this airplane type under the originally 
certificated safe-life provisions (augmented by damage-tolerance-based 
inspection of those parts of the structure where this was practicable) 
was the most appropriate course of action for ensuring the 
(certification) level of safety of these airplanes is preserved. The 
commenter also notes that Transport Canada issued AD CF-96-15 on 
September 17, 1996, for all models of the DHC-6 Twin Otter airplanes 
requiring these additional actions to ensure continued structural 
integrity. The commenter notes the FAA has not mandated this program 
and requests that the FAA do so as part of its aging airplane safety 
initiative. Additionally, according to Bombardier, the retirement time 
for the DHC-6 (100,

[[Page 72744]]

200, or 300 series) is 66,000 hours or 132,000 flights, whichever 
occurs first. According to Bombardier, the design-life goal for the 
DHC-6 is identified incorrectly in the proposed appendixes as 33,000 
hours.
    One FAA-approved repair station specializing in the major repair, 
alteration, and heavy maintenance of DHC-6 airplanes notes DHC-6 
component life limits are provided in deHavilland PSM 1-6-11, 
``Structural Components Service Life Limits.'' The structural 
components addressed in this document include the wing box, strut, and 
FS 219 fuselage lower frame. According to the commenter, these 
``manufacturers'' limits have been validated successfully through 
decades of field experience. The use of damage tolerance analysis to 
further assess airplane structure is redundant. According to the 
commenter, although certain remaining components might be subject to 
further structural fatigue evaluation, several of these components are 
either replaceable, already inspected at continuous intervals, or not 
considered fatigue-critical. The commenter states a more appropriate 
fatigue analysis approach would be to establish safe-life criteria for 
these additional components.
    Transport Canada states that the NPRM statement ``This Canadian AD, 
issued in September of 1996, mandates the retirement of the airplane at 
66,000 hours'' is incomplete. Airplane retirement at 66,000 hours is 
dependent on the completion of the mandatory supplemental integrity 
requirements in Canadian AD CF-96-15. To achieve the 66,000-hour 
design-life goal, a program of inspections and parts replacements is 
required. Transport Canada recommends that the statement be amended to 
say, `` * * * the retirement of the airplane at 66,000 hours is 
required as a result of AD CF-96-15, providing all the requirements of 
the AD are accomplished.''
    Transport Canada also states that the DHC-6 meets the requirements 
of Sec.  511.34 of the Canadian Aviation Regulations, Supplemental 
Integrity Instructions, per Transport Canada AD CF-96-15, which 
requires additional actions to ensure continued structural integrity as 
an airframe ages. Transport Canada was unaware of a similar FAA-
mandated AD.
    Twin Otter International, Ltd. (TOIL), states that the DHC-6 should 
not have to comply with damage-tolerance-based inspection techniques 
for the following reasons:
    [sbull] deHavilland designed the Twin Otter (DHC-6-300) with the 
intention that fatigue-critical components (that is, fuselage 
mainframe, wing struts, and wing boxes) must be replaced upon reaching 
either a flight hour or a cycle limit, whichever occurs first. Although 
the life limit of the wing struts and fuselage mainframe originally 
were established at 30,000 hours/60,000 cycles, Transport Canada, in 
revision 4 to the life limits manual (Structural Components Service 
Life Limits Manual, PSM-1-6-11), raised the wing strut life to 36,000 
hours/72,000 cycles and the mainframe life to 39,000 hours/78,000 
cycles. These components are inspected frequently using strict damage 
criteria. The commenter notes that the life of wing boxes (30,000 
hours/60,000 cycles) can be raised to 33,000 hours/66,000 cycles with 
incorporation of a service bulletin that adds structural reinforcement. 
The commenter adds that each of these components is inspected 
frequently in accordance with strict damage criteria. Also, upon 
reaching their life limits, the components must be replaced completely 
or, in the case of wing boxes, re-lifed (which may be done only once). 
Because of re-lifing, Transport Canada established a safe life for DHC-
6 wing boxes of 66,000 hours/132,000 cycles. TOIL also notes that two 
STCs have been approved to extend the life of DHC-6-300 wing boxes.
    [sbull] TOIL maintains its DHC-6 airplanes in accordance with the 
factory inspection and maintenance program Equalized Maintenance for 
Maximum Availability (EMMA), which requires certain scheduled 
inspections every 100 hours. If EMMA is followed, TOIL states that 
there is no additional benefit to implementing damage-tolerance-based 
inspection procedures.
    [sbull] TOIL believes corrosion, not structural fatigue, is the 
cause of structural damage in the DHC-6. TOIL reminds the FAA that on 
August 24, 1994, Transport Canada issued an AD requiring all DHC-6 
airplanes to be subject to exhaustive and repetitive corrosion 
inspections.
    [sbull] In 1994, the Aviation Rulemaking Advisory Committee (ARAC) 
Technical Oversight of Aging Airplanes working group generally accepted 
the ``manufacturer's'' method of ensuring continued structural 
integrity based on structural fatigue analysis, fatigue tests, and 
field experience correlation. Additionally, TOIL notes that the AASA 
does not mandate damage-tolerance-based analysis and inspection 
techniques. However, the AASA recognizes that the continued 
airworthiness of airplanes could be ensured through other means, 
particularly those airplane designs not based on damage tolerance 
guidelines.
    FAA Response: The FAA believes that the commenter's reference to 
the ARAC Technical Oversight of Aging Airplanes group actually refers 
to the Technical Oversight Group Aging Aircraft (TOGAA) that works with 
the FAA, but that group does not directly participate in ARAC group 
activities. The FAA assumes that the commenter is referring to the 
TOGAA in its comment.
    In November 1996, the Commuter Assessment Review Team (CART), which 
included members from the TOGAA, visited deHavilland to determine what 
difficulties were associated with conducting a damage tolerance 
assessment of the DHC-6. The CART found that deHavilland had the 
capability to perform a damage tolerance assessment of the DHC-6 if 
they chose to do so. At that meeting, the members of the TOGAA on the 
CART recommended that deHavilland perform a damage tolerance assessment 
of the DHC-6.
    Congress, through the AASA, instructed the Administrator to 
``prescribe regulations that ensure the continuing airworthiness of 
aging aircraft.'' The AASA also stated that air carriers must 
``demonstrate to the Administrator, as part of the inspection, that the 
maintenance of the aircraft's age-sensitive parts and components has 
been adequate and timely enough to ensure the highest degree of 
safety.''
    The FAA has determined that to ensure the continuing airworthiness 
of these aging aircraft, each airplane operated under part 121, each 
U.S.-registered multiengine airplane that was initially certificated 
with 10 or more passenger seats operated under part 129, and each 
multiengine airplane that was initially certificated with 10 or more 
passenger seats operated in scheduled operations under part 135 should 
be required to have a damage-tolerance-based SSIP included in its 
maintenance or inspection program.
    For the DHC-6, if the aircraft is used in any of the affected 
operations, then the operator must have a damage-tolerance-based SSIP 
included in each aircraft's maintenance or inspection program, in 
accordance with the schedule in this rulemaking.
    Regarding the commenter's discussion of component life limits, the 
FAA used these limits to establish the design-life goal for many of the 
airplanes identified in the appendixes. The design-life goal for the 
DHC-6 was chosen based on the wing life-limit of 33,000 hours. Also, 
the FAA has determined that a damage-tolerance-based SSIP must be 
accomplished for all airplanes initially certificated with 10 or more 
passenger seats. In addition, for DHC-6 airplanes

[[Page 72745]]

that are in service 4 years after the effective date of the rule and 
have not yet reached the design-life goal, the FAA has determined that 
a damage-tolerance-based SSIP must be in place by 33,000 hours or by 
December 20, 2010, whichever occurs sooner. As a result, the FAA has 
not issued an AD similar to Canadian AD CF-96-15.
    Comments: One Alaskan commenter argues that no replacement 
airplanes are being manufactured that can match the rugged and 
unpressurized DHC-6 Twin Otter. The commenter uses the airplanes to 
provide essential service to many communities in Alaska that have no 
other source of air transportation. The commenter claims that 
relegating the airplanes to part 135 cargo operations as a result of 
the rule change would be a great disservice to the Alaskan people and 
would degrade safety because the airplanes would be replaced by single-
engine, single-pilot airplanes with nine or fewer passenger seats.
    FAA Response: Regarding the Alaskan commenter's contention that the 
DHC-6 provides essential service to many communities in Alaska, the FAA 
has decided to permit relief from all requirements of this rule for 
those airplanes operating between any point within the State of Alaska 
and any other point within the State of Alaska. This change is 
reflected in Sec. Sec.  121.368(a), 121.370a(a), 135.168(a), 
135.422(a), and 135.422a(a).
Embraer EMB-110
    Comments: Empresa Brasileira de Aeronautica S.A. (Embraer) states 
that the expected fleet in operation by December 2010 would have a 
substantial residual life (based on original certification criteria). 
The proposed rule would significantly impact operators and 
``manufacturers'' and would put a sizeable portion of the EMB-110 fleet 
in an economically impracticable situation unless the FAA makes some 
simplified methodology available.
    Embraer understands that the particular characteristics of each 
airplane's design would be taken into consideration to allow 
alternative courses of action. In the case of the EMB-110, two facts 
must be taken into account: (1) Contrary to the proposal, the EMB-110 
is not a pressurized airplane, and (2) a service bulletin permitting 
the extension of the ``design service goal'' from 30,000 to 45,000 
flight hours is available.
    FAA Response: The FAA acknowledges the comment; however, the 
commenter did not provide any evidence that the 45,000 flight hour 
design-life goal in the service bulletin has been approved by the 
Brazilian regulatory authority. Therefore, the FAA is not changing the 
design-life goal of the EMB-110 from 30,000 to 45,000 flight hours. 
These airplanes will be required to have a damage-tolerance-based SSIP 
within the timeframes mandated in this rulemaking. The FAA encourages 
Embraer to support development of the damage-tolerance-based SSIP for 
the EMB-110.
Piper Navajo and PA-31 Series
    Comments: One operator indicates it has spoken with a 
representative from New Piper, Inc., regarding the impacts of this 
proposal. The commenter notes that the Piper Aircraft Corporation that 
originally produced the PA-31 series went bankrupt. New Piper, Inc., 
supports out-of-production airplanes only on any issues affecting the 
airworthiness of those airplanes. The commenter fears that because 
Australia and the United Kingdom already have established an arbitrary 
maximum airframe limit, New Piper simply might endorse that limit. The 
commenter opposes such acceptance. The commenter notes that the Piper 
Chieftain series of airplanes have relatively few stresses placed on 
them compared to pressurized airframes.
    One Alaskan operator states that the design lives set for the PA-
31-350 airplanes (excluding the pressurized version) appear to have no 
basis and are unrealistically low. The average fleet service life 
already exceeds the design life set by the proposal. The commenter 
knows of no failures of primary structure on these airplanes that would 
justify attributing such a limit to aging. According to the operator, 
neither the FAA nor the ``manufacturer'' has set a design-life goal on 
the airplanes, and it is unreasonable to rely on a design life set by a 
foreign country that did not certificate the airplanes. The commenter 
also states that there is no evidence that the foreign country 
conducted any analysis to develop the design life for the airplanes. 
The commenter's company has operated several PA-31-350 airplanes in 
excess of 20,000 hours total time without any indication that the 
airplanes have reached their design life.
    FAA Response: The FAA has revised the rule so that operators of 
airplanes initially certificated with nine or fewer passenger seats may 
develop a service-history-based SSIP instead of a damage-tolerance-
based SSIP.
Short Brothers SD3-30
    Comments: The European Aging Aircraft Working Group (EAAWG) states 
that the SD3-30 meets the requirements of AC 91-56 and the FAA should 
consult the ``manufacturer'' to clarify this issue.
    FAA Response: Through informal discussions with the U.K. CAA, the 
FAA has learned that the Short Brothers 3-30 and 3-60 airplanes meet 
the intent of AC 91-56, but the U.K. CAA is unable to present 
documentation to confirm that the FAA has previously accepted the U.K. 
CAA finding. This final rule requires that the operators of these 
airplanes include damage-tolerance-based SSIPs in the maintenance 
program for each airplane within the timeframes in this rulemaking. If 
the type certificate holder can demonstrate that the existing 
maintenance program for each airplane meets the intent of AC 91-56, 
then compliance with this rule will be made considerably easier for 
each operator. Operators can use the type certificate holder's program 
as the basis for their damage-tolerance-based SSIPs, altering each one 
as necessary to account for any modifications and repairs incorporated 
into specific airplanes in an operator's fleet.
    Because documentation from the U.K. CAA is not available at the 
time this final rule is being published, the economic analysis portion 
of this rule reflects costs associated with development of damage-
tolerance-based SSIPs of the Short Brothers 3-30 and 3-60 airplanes 
assuming none currently exist.
Short Brothers SD3-60
    Comments: Bombardier Aerospace Short Brothers (USA), Inc., states 
that the proposal lists a design-life limit of 28,800 hours for the 
SD3-60. However, the commenter states that type certificate data sheet 
A41EU, note 3, states the life limit is as listed in chapter 5 of the 
approved Maintenance Manual Document Ref. 360/MM. According to the 
commenter, this manual states the airplane has an economic structural 
limit of 57,600 flight hours or 100,000 flights (whichever occurs 
first). The commenter notes that the manual requires a structural half-
life audit at 28,800 flight hours or 50,000 flights.
    The EAAWG states that the SD3-60 meets the requirements of AC 91-56 
and the FAA should consult the ``manufacturer'' to clarify this issue.
    FAA Response: Through informal discussions with the U.K. CAA, the 
FAA has learned that the Short Brothers 3-30 and 3-60 airplanes meet 
the intent of AC 91-56, but the U.K. CAA is unable to present 
documentation to confirm that the FAA has previously accepted the U.K. 
CAA finding. This final rule requires that the operators of

[[Page 72746]]

these airplanes include damage-tolerance-based SSIPs in the maintenance 
program for each airplane within the timeframes in this rulemaking. If 
the type certificate holder can demonstrate that the existing 
maintenance program for each airplane meets the intent of AC 91-56, 
then compliance with this rule will be made considerably easier for 
each operator. Operators can use the type certificate holder's program 
as the basis for their damage-tolerance-based SSIPs, altering each one 
as necessary to account for any modifications and repairs incorporated 
into specific airplanes in an operator's fleet.
    Because documentation from the U.K. CAA is not available at the 
time this final rule is being published, the economic analysis portion 
of this rule reflects costs associated with development of damage-
tolerance-based SSIPs of the Short Brothers 3-30 and 3-60 airplanes 
assuming none currently exist.
Short Brothers SD3-Sherpa
    Comments: Short Brothers PLC proposes that the FAA amend the 
proposal so that (1) the reference to SD3-30 in line 4 of the proposed 
appendixes section of the preamble for the Short Brothers SD3-Sherpa 
(64 FR 16304) correctly reads ``SD-3 Sherpa''; (2) 40,000 hours in line 
10 reads ``35,000 flights''; and (3) the SD3-60 Sherpa airplanes and 
the following descriptive text be included:

    The Short Brothers SD3-60 Sherpa is a 32-seat airplane 
configured for 30 passenger seats and 2 pilot seats. The SD3-60 
Sherpa was certificated in the United States in 1996 under U.K. 
certification basis and to the additional validation requirements of 
part 25, Amendment No. 35. The ``manufacturer'' has limited the 
maintenance program to 12,000 flights as defined in the airplane 
maintenance manual.

    FAA Response: The FAA recognizes that some of the references made 
to the SD3-60 and SD-3 Sherpa as stated in the NPRM (64 FR 16304) were 
incorrect. All of the appendices in the final rule have been revised to 
reflect the correct information.

Non-Damage-Tolerance-Based Structural Supplemental Inspection Programs

    Summary of Proposal/Issue: The FAA notes that non-damage-tolerance-
based SSIPs based on AC 91-60, ``The Continued Airworthiness of Older 
Airplanes,'' have been mandated by ADs on the following airplanes: 
Convair 340, 440, 580, and 600 series; Douglas DC-3 and DC-6; Fokker F-
27; and Lockheed Electra. Although inspections and procedures based on 
AC 91-60 address known service difficulties, they do not anticipate the 
possibility of future fatigue cracks that could be predicted through 
the use of damage tolerance principles. The FAA has determined that 
some inspection programs developed in accordance with AC 91-60 do not 
qualify as damage-tolerance-based inspections and procedures because 
they are either based solely on service experience or combine partial 
damage-tolerance-based assessments with service experience. For these 
reasons, the proposed rule would not allow continued use of inspection 
programs based on AC 91-60 alone. Instead, the FAA proposes to require 
damage-tolerance-based inspections and procedures to supplement or 
replace existing inspection programs based on AC 91-60 no later than 
December 20, 2010.
Inspection Programs in Accordance With AC 91-60
    Comments: The GAMA notes, contrary to the FAA's statements, that 
some AC 91-60 inspections and procedures programs have been designed to 
anticipate the possibility of future cracking in the structure and have 
specified appropriate inspections and procedures to find such 
occurrences. The FAA should revise its incorrect and broad 
generalization.
    FAA Response: The FAA agrees. The existing AC 91-60 inspection 
programs were accomplished by different type certificate holders that 
made different assumptions to create their individual programs. The FAA 
understands that differences exist between these programs. The minimum 
standard for a service-history-based SSIP was provided in AC 91-60.
Fokker F-27
    Comments: Several commenters question the FAA's assertion that the 
Fokker F-27 ``SIP'' is not based on damage tolerance principles. 
According to these commenters, the Fokker F-27 ``SIP,'' Document No. 
27438, part 1, has been declared by the FAA as having been prepared in 
accordance with AC 91-56, ``Supplemental Structural Inspection Program 
for Large Transport Category Airplanes,'' which qualifies the program 
as an acceptable damage-tolerance-based inspection program. One 
operator notes Fokker performed full-scale and detailed tests as well 
as fatigue analysis (calculations) of the Fokker F-27 primary structure 
during the original certification process of the airplane. These tests 
were performed to ultimate loads. The fatigue inspection requirements 
and structural life limits resulting from those tests were included in 
the ``SIP.'' Additionally, the operator notes Fokker continues to add 
service experience, including stress corrosion, to the program. Also, 
Fokker continues to evaluate the areas of concern, new designs and 
developments, and service experience using damage tolerance 
assessments.
    FAA Response: The FAA agrees. Based on a review of our records, the 
FAA has determined that the Fokker F-27 SSIP mandated by AD was 
approved by the FAA as a damage-tolerance-based inspection program in 
compliance with AC 91-56.
Convair 580
    Comments: One operator states the Convair 580 has had excellent 
engineering and product support for over 45 years and has a well-proven 
structural integrity inspection document and corrosion inspection 
programs. The operator also asserts that it has implemented AD 88-22-06 
(revised to AD 92-06-06), ``Boeing: Amendment 39-6490,'' and AD 92-25-
13, ``General Dynamics, Convair Division: Amendment 39-8427.'' 
According to the operator, implementation of these ADs added 132 new 
inspection tasks relating to the AASA. Additionally, the operator has 
implemented AD 90-13-13, ``General Dynamics (Convair): Amendment 39-
6638,'' and AD 74-16-01, ``General Dynamics: Amendment 39-1904, as 
amended by Amendment 39-3206.'' Another commenter states the type 
certificate data sheet holder for the Convair 580 indicated it would 
cost approximately $2.5 million for an operator of this airplane to 
develop a damage-tolerance-based ``SIP,'' because the historical data 
required for development do not exist.
    FAA Response: The FAA has determined that Convair 340/440/580 
aircraft can operate until December 20, 2010. At that time, a damage-
tolerance-based SSIP will be required. The FAA encourages the current 
type certificate holder to develop a damage-tolerance-based SSIP to 
support this airplane in service.
Lockheed L-188 Electra
    Comments: According to one operator, the Lockheed L-188 Electra SID 
program was developed using damage-tolerance-based principles and was 
not based solely on empirical service data. In a separate comment, 
Lockheed Martin Aeronautical Systems (Lockheed) indicates to operators 
of the Lockheed L-188 Electra that the cost to develop an aging 
airplane program and perform its inspections and modifications would 
need to be

[[Page 72747]]

addressed by each operator. According to Lockheed, operators should 
consider the following options:
    [sbull] Individually or as a group, develop an Electra aging 
airplane program;
    [sbull] Fund a third party to develop an Electra aging airplanes 
program, which Lockheed would be willing to do if funded by operators; 
or
    [sbull] Petition the FAA for relief using the AC 90-60 non-damage-
tolerance-based ``SIP'' issue to defer action until 2010.
    FAA Response: The FAA agrees. Based on a review of our records, the 
FAA has determined that the Lockheed L-188 SSIP mandated by AD was 
approved by the FAA as a damage-tolerance-based SSIP in accordance with 
AC 91-56.
DC-6 and C-46
    Comments: One commenter who currently operates Douglas DC-6 and 
Curtiss C-46 airplanes notes it may continue to operate either or both 
types of airplanes beyond 2010. The commenter further states that if it 
does upgrade to newer airplanes, the newer airplanes probably will not 
have damage-tolerance-based inspections in their maintenance programs. 
Additionally, the commenter notes the lack of ``manufacturer'' support 
in developing adequate damage-tolerance-based ``inspection programs.'' 
According to the commenter, the Curtiss company no longer supports its 
airplanes. Also according to the commenter, Boeing (which acquired 
Douglas) has indicated to the commenter that it is not considering 
supporting the DC-6 (and probably nothing older than the DC-10) in this 
area.
    FAA Response: The FAA has established that a damage-tolerance-based 
SSIP must be developed for the DC-6 by December 2010 and for the C-46 
within 4 years after the effective date of the rule, or those airplanes 
will not be eligible for operations in part 121, or part 129, or in 
scheduled operations in part 135. In the future, operators of these 
airplanes will have to make decisions on how best to support the 
operation of these airplanes.
Other FAA Initiatives
    Comments: One commenter singled out the Fokker F-28 jet, noting 
there was significant activity a few years ago on a repair assessment 
program for elements of damage tolerance. According to the commenter, 
because there has been no regulatory activity (that is, establishment 
of repair requirements) on repairs for the Fokker F-28, it would be 
inappropriate to review repairs for damage-tolerance-based inspections.
    FAA Response: The final rule titled ``Repair Assessment for 
Pressurized Fuselages'' (65 FR 24108, April 25, 2000) that became 
effective May 25, 2000, is applicable to the Fokker F-28. Therefore, 
operators must make a damage tolerance assessment of the repairs to the 
Fokker F-28 fuselage pressure boundary.

Discussion of Economic or Cost Comments

    Summary of Proposal/Issue: In accordance with Executive Order 
12866, the FAA prepared an economic analysis of the proposed changes to 
the Code of Federal Regulations. The FAA assessed the costs associated 
with the following items:
    [sbull] Implementation of damage-tolerance-based inspections and 
procedures for those scheduled operators of multiengine airplanes not 
currently subject to these inspections and procedures.
    [sbull] Operator development of these procedures for the affected 
airplane models.
    [sbull] Additional FAA inspections and records reviews mandated by 
Congress.
    The FAA noted in its analysis that the attributed costs of this 
proposal do not include the expense of making repairs that may be found 
necessary during either an operator's damage-tolerance-based 
inspections or the FAA's oversight inspections. The FAA does not 
attribute these repair costs in the proposal because current 
regulations require that repairs be made as necessary to ensure the 
airworthiness of an airplane. Also, the FAA noted that its analysis did 
not address directly the costs the proposal eventually would impose on 
airplanes produced after the effective date of the rule.
    The FAA identified two benefits in the proposed rule: (1) Age-
related accidents would be prevented and (2) the FAA and the industry 
would be able to monitor the airworthiness of the affected airplanes as 
they age and either take timely corrective action to maintain their 
continued airworthiness or retire them from service before they become 
unairworthy; consequently, the airplanes would be able to stay in 
service longer because their continued airworthiness would be 
monitored, rather than the airplanes being retired at an arbitrary age.
    Comments: Commenters generally believe the FAA underestimated the 
costs associated with this proposal. One commenter provided the 
following comments regarding the Initial Regulatory Flexibility 
Determination completed by the FAA: In the ``Compliance Assistance'' 
section, the NPRM indicates the FAA has undertaken a research program 
to develop a simplified damage-tolerance-based methodology directly 
applicable to commuter-sized airplanes. The company states that if this 
document has not yet been issued, the FAA should consider withholding 
issuance of the final rule until such adequate guidance material is 
available.
    FAA Response: In its efforts to assist small entities and other 
affected parties in complying with the rule, the FAA will publish two 
ACs for comment with this final rule. One of these is AC 91-56B, 
``Continuing Structural Integrity Program for Airplanes,'' and it will 
provide guidance for implementing a damage-tolerance-based SSIP. The 
other document is AC 91-60A, ``The Continued Airworthiness of Older 
Airplanes,'' which will provide guidance for implementing a service-
history-based SSIP. Notices of availability for these two ACs are 
published concurrently with this rule, with a request for public 
comments. The research referred to by the commenter has not yet been 
published. The document is in final review and will be published in the 
near future.
    Comment: Additionally, the GAMA and other commenters contend the 
following statement is incorrect for ``SIPs'' developed using 
comprehensive fatigue analysis, fatigue tests, and the correlation of 
field service data, as applicable: ``* * * non-damage-tolerance-based 
program would induce lower costs but with a concomitant reduction in 
safety assurance'' (64 FR 16314). Also, GAMA states this statement 
contradicts the FAA's assertion that the proposed rule does not 
increase the intended level of safety but maintains the level of safety 
established at type design (64 FR 16311).
    FAA Response: The FAA maintains that damage-tolerance-based SSIPs 
provide the highest level of safety and that service-history-based 
SSIPs provide something less than that. In the NPRM, the FAA proposed 
that full damage-tolerance-based SSIPs be imposed on all affected 
airplanes after 2010. After reviewing the comments, the FAA had to 
consider the cost, the exceptional difficulty in obtaining the 
necessary data for airplanes with fewer than nine seats, and the 
capability of the airlines operating these smaller airplanes to 
effectively accomplish these requirements. As a result of the review 
and based on the comments received, the FAA is revising the proposal to 
allow airplanes initially certificated

[[Page 72748]]

with nine or fewer passenger seats to have service-history-based SSIPs.
    Comment: The ATA estimates aligning HMCs with the inspections at 5-
year intervals alone would cost more than $1.3 billion. According to 
ATA, one member states this alignment would add $21 million annually to 
its costs. Another ATA member asserts the proposal would require each 
airplane to be kept in heavy maintenance a minimum of 2 days longer 
than scheduled (compared with the FAA's estimate of 0.7 to 1.6 days). 
According to that operator, this additional time would result in 
$80,000 in lost revenue (compared with the FAA's estimate of 7 percent 
of the value of capital, or $2,700 per inspection). Another ATA member 
with 230 airplanes estimates the proposed rule would cost that operator 
as much as $150 million during each 5-year cycle and recommends the FAA 
consider a separate rule for part 121 operators of large transport 
category airplanes. Six ATA members representing more than 50 percent 
of the total domestic ATA fleet estimate the proposed rule would cost 
the group of part 121 operators of large transport category airplanes 
more than $236 million per year.
    FAA Response: Based on the comments received, the FAA has changed 
the repeat inspection and records review interval from 5 years to 7 
years to allow an operator to align the inspection and records review 
interval more closely with the scheduled HMC interval. This does not 
require the operator to have its HMC at the initial or repetitive 
limits set by this rule. The scheduled HMC can occur at any time within 
those intervals, and the FAA inspection and records review can be held 
concurrently with the HMC. The intervals shown in the rule are maximum 
intervals. In addition, it is not the FAA's intent to disrupt 
operators' scheduled maintenance in such a way that it would 
significantly impact their schedules. However, each airplane subject to 
the final rule cannot be returned to service after the specified 
interval until the Administrator or a designee has completed its 
inspection and records review and notifies the operator accordingly.
    With regard to cost estimation, a time estimate of 2 days per 
airplane inspection, as suggested by the commenter, was used in the 
final regulatory evaluation for the oversight inspection of an airplane 
by an ASI or DAR. This time estimate was used for the large transport 
airplanes that have damage-tolerance-based SSIPs (the great majority of 
the affected airplanes).
    With regard to downtime costs, the FAA maintains that a reasonable 
approximation of the cost for the oversight inspection of an airplane 
by ASIs/DARs is the rate of return applied to the value of the 
productive capital asset used by the business enterprise (rather than 
revenue lost per day). Seven percent is the rate of interest that OMB 
directs agencies to use in present-value calculations. Moreover, such 
an approach has the advantage of being applied uniformly over the 
entire air carrier industry. By comparison, ``revenue lost per day'' 
varies considerably across companies in the industry and is affected by 
different accounting procedures. In addition, utilization rates vary 
across equipment. The FAA estimates the total cost to the industry 
where revenue lost by one firm is gained by another.
    Calculations were made that resulted in estimates of intervals 
between C-checks and D-checks, in terms of years, for some large 
transport airplanes (including Boeing models). These calculations 
showed that the C-checks take place, on the average, every 1 to 2 years 
depending on the airplane model type. D-checks are estimated to take 
place, on the average, every 5 to 12 years depending on the airplane 
model type. Thus, the initial inspection and records review (4 or 5 
years after the effective date of the rule) could likely take place at 
a C-check; while the repeat inspection and records review, at 7-year 
intervals, could take place at a D-check or a C-check. In addition, 
those operators that use a segmented D-check schedule will have more 
opportunity to accommodate the initial and repeat inspections and 
records reviews. The increasing use of non-destructive inspection 
techniques should facilitate inspections at C- or D-checks.
    Comment: One operator states the FAA assumption that only 50 
percent of all fleets affected by the proposal would require 
modification is too conservative. The operator contends almost 100 
percent of the fleets mentioned in the proposal would have to be 
modified to some extent. The operator further states the high costs of 
this modification would cause many operators to go out of business.
    FAA Response: In the NPRM, the FAA's cost estimates for 
modifications included airplanes initially certificated with nine or 
fewer passenger seats (part 135), because they also were supposed to 
implement damage-tolerance-based SSIPs. This group of airplanes will 
now be required to implement service-history-based SSIPs. Consequently, 
the number of airplanes needing modifications is reduced. However, 
there has been an increase in the number of part 121 airplanes needing 
damage-tolerance-based SSIPs since the publication of the NPRM.
    Therefore, in the absence of substantiation to support the 
contention of the comment, the economic analysis keeps the 50 percent 
as a reasonable estimate.
    Comment: Based on its own economic analysis of the effects of a 5-
year fixed interval ``on airplane'' inspection with extensive 
additional access, one part 121 air carrier states the proposal would 
result in an increased maintenance expense of $404 million for that 
carrier's fleet alone. The carrier asserts this expense would affect 
future travel costs but provide no increase in passenger safety for 
part 121 operations.
    FAA Response: Based on the comments received, the FAA has changed 
the repeat inspection and records review interval from 5 years to 7 
years to allow the operator to align the inspection and records review 
interval more closely with the scheduled HMC interval (C-check or D-
check).
    Comment: One commenter states the FAA's cost impact analysis on air 
carrier records preparation does not account for the time carrier 
employees spend during the inspections and records reviews. The 
commenter notes that a carrier's employees would have to prepare the 
airplane records as well as provide a support role during the 
inspections and records reviews.
    Another commenter states the FAA failed to consider adequately the 
costs of reviewing each repair on each airplane, updating airplane 
structural repair manuals for damage tolerance repairs, and training 
professional engineering personnel in damage tolerance repair design.
    FAA Response: In the NPRM and the final regulatory evaluation, 
there is cost estimation for personnel of the operator to prepare the 
airplane and its records for the inspection and records review by ASIs 
or DARs.
    The FAA estimated the cost of damage-tolerance-based SSIPs per 
affected airplane, including repairs.
    With regard to updating airplane structural repair manuals (SRMs), 
that cost should be minimal and it is included in the development and 
review cost. Several type certificate holders of large transport 
category airplanes have already updated their SRMs to include the 
results of damage tolerance assessments of repairs.
    With regard to training professional engineering personnel, the 
commenter does not provide information as to the purpose of the 
training for professional engineers in damage tolerance repair

[[Page 72749]]

design. The cost of engineering time to develop damage-tolerance-based 
SSIPs has been estimated using a fully burdened engineering rate of $95 
per hour. This rate can be applied for engineering services (to develop 
the SSIP) provided by the type certificate holder, a consulting firm, 
or the operator's own engineering personnel.
    Comment: One part 135 Alaskan operator provided the following 
comments regarding costs of the proposed rule:
    [sbull] The FAA expects operators to work with STC holders and the 
original airplane ``manufacturer'' to develop damage-tolerance-based 
supplemental inspection programs, which would require that each unique 
combination of type design and STC require a separate inspection 
program. The commenter therefore asserts the cost analysis is off by a 
factor equal to the number of unique type design and STC combinations 
for each type design.
    [sbull] The FAA's estimate that 209 part 135 multiengine airplanes 
would be affected by this rule seems low. (ADOT&PF agrees, estimating 
that approximately 727 of the 3,198 airplanes in commercial service in 
Alaska would be affected (the airplanes not counted are single-engine 
airplanes). According to the ADOT&PF, almost all of these airplanes are 
more than 14 years old and none have a current damage-tolerance-based 
inspection program.)
    [sbull] The commenter does not disagree with the FAA's reasons for 
excluding the costs of repairs that may result from an operator's 
damage-tolerance-based inspections or the FAA's oversight inspections; 
however, because air carriers should maintain their airplanes in an 
airworthy condition, the new regulations are redundant.
    [sbull] The enormous costs associated with the proposal would 
deplete the pool of funds available to maintain airplanes and limit the 
use and development of other more efficient initiatives that could 
improve aging airplane safety at a lower cost. The commenter cites two 
examples: (1) Requiring replacement of all avionics and autopilot 
wiring after 25 years of service, and (2) requiring all commuter 
carriers to operate only under instrument flight rules.
    [sbull] The proposed rule places the economic burden on operators, 
not ``manufacturers'' as stated in the NPRM. The operator notes the 
redundant expenses operators would incur in developing ``SIPs.''
    [sbull] The operator questions the FAA's assumption that developing 
``SIPs'' for related models would produce efficiencies. The commenter 
indicates operators would be unwilling to develop ``SIPs'' for models 
related to their own models. Furthermore, if an operator did develop a 
``SIP'' that might be useful to other operators, the developing 
operator would be hesitant to transfer development information without 
charging a fee.
    [sbull] The proposal underestimates the costs associated with 
developing damage-tolerance-based inspection techniques. According to 
the operator developing such techniques may (1) take more than 80 hours 
and (2) require extensive training for mechanics responsible for 
implementing the programs.
    [sbull] The FAA's estimated 20-year annualized cost stream figure 
is misleading and inaccurate because operators would face costs sooner 
than 20 years. Furthermore, the economic analysis fails to consider 
costs beyond 2018.
    [sbull] The economic analysis fails to consider that financing 
costs are particularly high for commuter operators.
    FAA Response: The final rule excepts part 135 multiengine airplanes 
initially certificated with nine or fewer passenger seats from the 
requirement to incorporate damage-tolerance-based SSIPs. These 
operators are to implement service-history-based SSIPs in 2010. Also, 
the rule provides an exception for those airplanes operated between any 
point within the State of Alaska and any other point within the State 
of Alaska.
    The final rule covers part 135 multiengine airplanes in scheduled 
service and the NPRM used a count of these airplanes. The commenter 
refers to a count of 727 airplanes as being in ``commercial'' service 
rather than in ``scheduled'' service. A count of airplanes in 
``commercial'' service includes scheduled and unscheduled operations.
    The rule places the responsibility for developing the SSIP on the 
operators. However, the FAA anticipates that a number of type 
certificate holders will choose to support the development of the SSIP 
because it affects the future marketability of their airplanes. For 
those cases where a type certificate holder does not develop a damage-
tolerance-based SSIP, the FAA anticipates that operators of a 
particular model will recognize the advantages of cooperating and 
jointly financing the development of a SSIP for that model. This can be 
done through the airplane type certificate holder or through an 
aviation engineering/consulting firm. Moreover, the final rule excepts 
part 135 multiengine airplanes initially certificated with nine or 
fewer passenger seats from implementing damage-tolerance-based SSIPs.
    With regard to efficiencies in developing SSIPs, that factor was 
removed from the cost-estimating methodology in the final regulatory 
evaluation. With regard to charging a fee, such a fee can be charged. 
Then, the cost of developing a damage-tolerance-based SSIP can be 
shared by all the affected operators.
    The development of a damage-tolerance-based SSIP was estimated in 
the NPRM to take between 10,000 to 25,000 hours. The 80 hours was an 
estimate of the time needed for an operator to incorporate the damage-
tolerance-based SSIP into its maintenance program.
    With respect to training mechanics, it is not expected that airline 
mechanics will need additional training to do damage-tolerance-based 
inspections. Airline mechanics, through their training and work 
experience, already have the necessary skills to do such inspections. 
Most airlines have nondestructive testing capability already and it is 
only a matter of including those inspections in their maintenance or 
inspections programs.
    The 20-year annualized cost does not mean that operators would not 
face costs sooner than 20 years. They will face costs sooner, and those 
costs have been incorporated in the economic assessment.
    The period used to analyze the costs of the rule is a 20-year 
period. In the NPRM, the time period was 1999-2018. In the final 
regulatory evaluation, it is 2001-2020. If the period becomes longer 
than this (e.g., 2001-2025), the estimated (undiscounted) costs of the 
rule will increase.
    The final rule contains relieving actions. Airplanes initially 
certificated with nine or fewer passenger seats have been excepted from 
damage-tolerance-based SSIPs and, instead, need to implement service-
history-based SSIPs in 2010. The repeat inspections interval has been 
increased from 5 to 7 years. Finally, the FAA will make available 
advisory material through AC 91-56B and AC 91-60A. This material will 
be useful to small and commuter operators.
    Comments: Commenters also note the FAA is unable to quantify the 
benefits associated with the proposed rule, thus the proposal seems 
unjustified. However, according to the GAMA, some reliable information 
on potential benefits associated with the proposed rule is available in 
the form of results compiled from the AATF program and other 
``manufacturer'' programs where results have been shared with the FAA.

[[Page 72750]]

    FAA Response: Based on the comments received, the FAA has revised 
the final rule to allow airplanes initially certificated with nine or 
fewer passenger seats to have service-history-based SSIPs. In addition, 
the FAA has decided to permit relief from the damage tolerance and SSIP 
requirements of this rule airplanes operating between any point within 
the State of Alaska and any other point within the State of Alaska. 
This change is reflected in Sec. Sec.  121.368(a), 121.370a(a), 
135.168(a), and 135.422(a).
    The FAA economic analysis provides a reasoned determination that 
the benefits of the rule justify the costs. The FAA and Congress 
believe that the risk of accidents does exist. This rule is expected to 
prevent aging aircraft accidents. The FAA and industry will be better 
able to monitor the aircraft airworthiness and thus comply with the 
AASA. This rule is expected to prevent potential aging-related 
accidents and to extend the airworthy life of affected aircraft.
    Comment: One commenter asserts the FAA must provide for alternative 
inspection methods other than those based on damage tolerance criteria. 
According to the commenter, maintaining a damage-tolerance-based 
inspection and records program is administratively cost prohibitive, 
especially for smaller carriers. Also, the FAA has failed to 
demonstrate that such alternative approaches are less safe than damage-
tolerance-based programs.
    FAA Response: The FAA maintains that damage-tolerance-based SSIPs 
provide the highest level of safety and that service-history-based 
SSIPs provide something less. In the NPRM, the FAA proposed that full 
damage tolerance inspections be imposed on all airplanes after 2010. 
After reviewing the comments, the FAA had to consider the cost, the 
exceptional difficulty in obtaining the necessary data for fewer than 9 
seats, and the capability of the airlines operating these smaller 
airplanes to effectively accomplish these requirements. As a result, 
based on the comments received, the FAA is revising the proposal to 
allow airplanes that were initially certificated with nine or fewer 
passenger seats to have service-history-based SSIPs.
    Comment: This commenter, who operates deHavilland DH-6 Twin Otter 
airplanes, presumes that deHavilland would not fund a damage-tolerance-
based program for the Twin Otter because the airplane has been out of 
production since 1988. The commenter also presumes that for liability 
reasons, deHavilland would not provide the necessary engineering and 
test data upon which a damage-tolerance-based program would be 
developed by operators of that airplane. Therefore, the commenter 
asserts it would have to retain a company such as Structural Integrity 
Engineering to develop its damage-tolerance-based ``inspection 
program.'' According to the commenter, Structural Integrity Engineering 
reports that the commenter should expect to spend between $500,000 and 
$600,000 on the analysis and an additional $250,000 in flight testing 
to validate flight loads and other criteria.
    Because of these liability concerns, the commenter would not sell 
its damage-tolerance-based ``inspection program'' to other DHC-6 
operators as a means of defraying the initial investment of at least 
$750,000. In addition, because more of its customers cannot afford to 
maintain personnel trained and certified in ultrasonic inspection 
techniques, the commenter would have to add additional personnel and 
keep them qualified to support its customers. According to the 
commenter, its ``lease rents'' would decline in proportion to increased 
maintenance costs. The commenter states it cannot place a cost on a 
reduction in rents or in how that income loss could reduce DHC-6 hull 
values. However, the commenter estimates it would cost at least 
$100,000 per year in additional personnel costs for the commenter and 
potentially reduce the DHC-6 hull values by between $400,000 and 
$500,000 (a total of $15.6 to $19.5 million for the commenter's fleet 
of 39 DHC-6s).
    FAA Response: The FAA recognizes that operators are responsible for 
the development of their inspection programs. However, the FAA expects 
type certificate holders to support the operators in the development of 
those programs. This should be particularly likely when the type 
certificate holder is still producing a particular airplane model, 
which is the case for the great majority of the affected airplane 
models. Operators of an airplane model also may engage and fund the 
type certificate holder of the airplane to develop a damage-tolerance-
based SSIP. In the event that a type certificate holder chooses not to 
support the airplane, and if the operator is unable to economically 
justify the development of the damage-tolerance-based inspections, 
along with other operators of the same model, the airplane will be 
ineligible for operation in scheduled service in the United States.
    Comment: An Alaskan operator obtained an estimate to develop a 
``SIP'' for PA-31-350 airplanes and was advised that without the 
original design data from the ``manufacturer,'' the cost would 
approximately double. For an airplane no longer in production, there is 
no incentive for ``manufacturers'' to voluntarily provide such data to 
the operator; it only extends their liability. The commenter alleges 
that ``manufacturers'' have strong incentives to impede the development 
of cost-effective ``SIPs'' for out-of-production models because 
withholding data would force airplane retirements and generate demand 
for new airplanes.
    FAA Response: Based on the comments received, the FAA is revising 
the proposal to allow airplanes initially certified with nine or fewer 
passenger seats to have service-history-based SSIPs, which includes the 
PA-31-350. However, for airplanes initially certificated with 10 or 
more passenger seats, a damage-tolerance-based SSIP is required to 
ensure the continuing airworthiness of these aircraft.
    Fairchild has developed a damage-tolerance-based SSIP for its Metro 
aircraft. However, the FAA realizes that other type certificate holders 
may choose not to support the development of SSIPs and that this may 
lead to the retirement of certain airplanes. The FAA notes that each 
operator, not the type certificate holder, is responsible for ensuring 
the continuing airworthiness of its aging aircraft.
International Trade Considerations
    One international operator submitted a comment on the International 
Trade Impact Analysis completed by the FAA. The operator states--
    [sbull] In encouraging foreign governments to adopt this proposal, 
the FAA must accept the inspection and review findings of those 
governments without further FAA-approved review or inspection. The 
operator indicates the CASA probably will adopt this NPRM; therefore, 
incurring costs for non-U.S.-registered fleets.
    [sbull] The international trade impact analysis is underestimated. 
The NPRM could affect international trade if restrictions apply to the 
importation of second-hand airplanes into the United States.
    Another international operator noted that the proposal will have an 
effect on foreign trade by increasing operating costs for foreign 
operators of U.S.-registered aircraft due to the additional costs 
associated with compliance with this rule.
    FAA Response: The commenter's assertion that the FAA must accept 
the inspection and review findings of foreign governments without 
further FAA-approved inspection and review is erroneous. The FAA agrees 
that if

[[Page 72751]]

another country adopts this rule, it will impact airplanes registered 
in that country; however, that cost is not a direct cost of this rule.
    The rule applies to all affected U.S.-registered airplanes. It does 
not apply to non-U.S.-registered airplanes. The FAA notes, however, 
that anyU.S.-registered airplane will be subject to the requirements of 
this rule whether it is purchased from a seller in a U.S location or 
from a seller in a foreign location. Owners of foreign-registered 
airplanes seekingU.S. registration and prospective owners of such 
airplanes are aware of the need to comply with applicable U.S. 
regulations and should take these requirements into account before 
attempting to transfer a foreign-registered aircraft to the U.S. 
registry. It is their responsibility to ensure that an aircraft 
imported into the United States complies with current U.S. regulatory 
requirements.

Editorial Comments

    Summary of Proposal/Issue: Several commenters addressed editorial 
items related to the proposed rule.
    Comments: Commenters recommend that the FAA--
    [sbull] Correct the appendix references in Sec.  135.168 to read 
``appendix G.''
    [sbull] Correct the appendix references in Sec.  121.370a to read 
``appendix N.''
    [sbull] Better define what is meant by the term ``age-related 
fatigue damage.'' The EAAWG asks whether the term means corrosion 
fatigue or refers to the more conventional understanding of damage 
resulting from repeated cyclic loading.
    [sbull] Better describe what is meant by ``fatigue.'' According to 
the EAAWG, the description of this term in the Description of Benefits 
section of the preamble to the proposal implies fatigue may be 
something other than cracking, although cracking is the specific 
concern of the proposal.
    [sbull] Reconsider the use of the term ``supplemental'' to refer to 
inspections in Sec. Sec.  121.370a, 129.16, and 135.168. According to 
the CASA, whether inspections are supplemental or integral to the basic 
maintenance program is irrelevant. Also, the CASA states these 
inspections increasingly would become integral rather than 
supplemental.
    FAA Response: The term ``age-related fatigue damage'' is damage 
resulting from repeated cyclic loading, not from corrosion. ``Fatigue'' 
is related to cracking only. The FAA disagrees with the comment on the 
use of the word ``supplemental.'' Such inspections are supplements to 
the normal maintenance program, and the use of the term 
``supplemental'' is accepted by the industry and is used in FAA 
advisory material.
    The FAA also has corrected the appendix references in Sec. Sec.  
121.370a and 135.16.

Other Issues

Part 23 Airplanes
    Comments: The NATA recommends that the FAA suspend the proposed 
rules for scheduled part 135 air carriers operating part 23 airplanes 
initially certificated with nine or fewer passenger seats. According to 
the NATA, currently there are no systemic structural problems in these 
airplanes that require implementing damage-tolerance-based inspections. 
The NATA proposes to assist the FAA in conducting evaluations of 
current inspection and maintenance requirements for these airplanes to 
determine whether an unsafe condition exists.
    The NATA proposes a different method of addressing aging concerns 
for part 23 airplanes initially certificated with nine or fewer 
passenger seats certificated before 1993:
    [sbull] The FAA should identify airplanes for which damage-
tolerance-based inspections have been developed and approved by the 
FAA.
    [sbull] The FAA should identify airplanes for which the 
``manufacturer'' has developed a SSIP or a supplemental corrosion 
inspection program.
    [sbull] For any airplane not covered by the above provisions, the 
FAA should develop a special inspection to enhance the scheduled 
periodic/annual inspection currently required. The inspections should 
be developed through the use of structural difficulty reports and other 
such reports available to the FAA.
    [sbull] The owner/operator of any affected airplanes in air carrier 
service should be required to implement, no later than 14 years after 
the date of manufacture, a SSIP designated by the ``manufacturer.'' If 
the ``manufacturer'' has not designated such a program, the operator 
should be required to implement the FAA's SSIP.
    FAA Response: The FAA disagrees with the suggested changes to the 
rule. However, based on the comments received, the FAA has amended the 
final rule to specify that airplanes initially certificated with nine 
or fewer passenger seats can accomplish service-history-based SSIPs 
instead of damage-tolerance-based SSIPs as proposed in the NPRM.
New Rulemaking Mandating CPCP and Other Programs
    Comments: One commenter proposes that the FAA initiate a new 
rulemaking to mandate structural integrity programs and CPCPs instead 
of AD action supplemented with structural and corrosion reliability 
programs for airplanes with non-damage-tolerance-based ``inspection 
programs.''
    FAA Response: The FAA agrees and is considering rulemaking to 
impose CPCPs for the same fleet of airplanes as is covered by this 
rule.
Operations Specifications
    Comments: One operator proposes an aging airplane program that 
would function through amendments to operations specifications. Under 
this program, an operator's quality department would have 
responsibility for records reviews, airplane inspections, and reporting 
of results. Also, the FAA could focus on providing oversight through 
sampling or unannounced inspections and records reviews.
    FAA Response: The FAA disagrees. The inspection programs must be 
approved by the FAA ACO or office of the Small Airplane Directorate or 
Transport Airplane Directorate responsible for each airplane's type 
certificate. The final rule has been revised to reflect this approval 
requirement. Once approved, each air carrier's operations 
specifications can be revised to include these inspections in each 
airplane's maintenance or inspection program.
DAR Services
    Comments: A number of commenters state that the FAA underestimated 
the cost for DAR services. One commenter states that the increased 
inspection and DAR costs would add significantly to the costs per 
flight hour for low utilization operators.
    Another commenter indicates he has been a DAR since 1983 and 
generally charges $125 per hour for services performed (based on 
appendix A to part 187, Methodology for Computation of Fees for 
Certification Services Performed Outside the United States, and AC 187-
1, Flight Standards Service Schedule of Charges Outside the United 
States). The ATA estimates the costs of hiring a DAR would be no less 
than $100 per hour, compared with the FAA's estimate of $55 per hour.
    Other commenters worry that the operator would have to bear the 
costs of the DAR inspections and records reviews. One operator states 
that some FAA offices routinely direct operators to

[[Page 72752]]

seek the services of a DAR whenever the task can be accomplished by a 
DAR, indicating the FAA office is too busy.
    FAA Response: The FAA has established that the benefit of doing the 
inspections and records reviews outweighs the associated costs of using 
DARs to accomplish these tasks. However, the FAA will establish policy 
on how DARs will be used, and the FAA has revised the regulatory 
evaluation to reflect the cost of DAR services.
    In the NPRM cost calculations, the FAA used $95 per hour for the 
burdened hourly wage of DARs. The FAA used $55 per hour for other types 
of skills. In the cost calculations of the final regulatory evaluation, 
the FAA used $100 per hour for the burdened wage rate of DARs. With 
regard to the availability of FAA inspectors, the cost-estimation 
methodology recognizes the possible obstacles with the supply and 
availability of FAA inspectors, and has consequently assumed that 60 
percent of this cost will be for the use of DAR services and 40 percent 
will be for the use of FAA inspector services. The total cost of the 
rule remains the same.

Regulatory Evaluation Summary

    Changes to federal regulations must undergo several economic 
analyses. First, Executive Order 12866 directs that each Federal agency 
shall propose or adopt a regulation only upon a reasoned determination 
that the benefits of the intended regulation justify its costs. Second, 
the Regulatory Flexibility Act of 1980 requires agencies to analyze the 
economic impact of regulatory changes on small entities. Third, the 
Trade Agreement (19 U.S.C. section 2531-2533) prohibits agencies from 
setting standards that create unnecessary obstacles to the foreign 
commerce of the United States. In developing U.S. standards, this Trade 
Act requires agencies to consider international standards and, where 
appropriate, that they be the basis of U.S. standards. And fourth, the 
Unfunded Mandates Reform Act of 1995 requires agencies to prepare a 
written assessment of the costs, benefits and other effects of proposed 
or final rules that include a Federal mandate likely to result in the 
expenditure by state, local or tribal government, in the aggregate, or 
by the private sector, of $100 million or more in any one year 
(adjusted for inflation).
    In conducting these analyses, the FAA has determined that this 
rule: (1) Has benefits which do justify its costs, is a ``significant 
regulatory action'' as defined in the Executive Order, and is 
``significant'' as defined in DOT's Regulatory Policies and Procedures; 
(2) will have a significant impact on a substantial number of small 
entities; (3) will have a neutral impact on international trade; and 
(4) does not impose an unfunded mandate on State, local, or tribal 
governments, or on the private sector. These analyses, available in the 
docket, are summarized below.

Introduction

    This rule represents a critical step toward compliance with the 
Aging Aircraft Safety Act of 1991. Section 44717 of title 49 instructs 
the Administrator to ``prescribe regulations that ensure the continuing 
airworthiness of aging aircraft'' and to ``make inspections, and review 
the maintenance and other records, of each aircraft an air carrier uses 
to provide air transportation.''
    Consistent with section 44717 of title 49, the purpose of the rule 
is to ensure the continuing airworthiness of aging airplanes operating 
in commercial air transportation. The implementation of this rule 
ensures that: (1) Modern damage-tolerance analysis and inspection 
techniques will be applied to older airplane structures that were 
certificated before such techniques were available, and (2) the FAA 
will conduct mandatory aging-aircraft inspections and records reviews.
    Since the publication of the NPRM, the FAA made changes to the 
final rule consistent with the enabling legislation to ensure the 
airworthiness of aging aircraft, while factoring in public comments 
about the economic consequences. The net effect is that all operators 
have more time to be in compliance with this rule and that operators of 
smaller aircraft implement less rigorous inspections. Despite these 
cost-reduction factors, the estimated total cost of the rule is higher 
than that initial regulatory evaluation, due to cost adjustments 
resulting from information provided by the industry.

Differences Between the Current Rules and the Aging Rule

    There is strong evidence that the current system of maintenance 
inspections is not working effectively in the detection, and repairing, 
cracks on airplanes during regular maintenance inspections, while these 
cracks are still small. This section discusses the differences between 
the current rules and the aging rule in order to show the focused 
emphasis of the aging rule toward the early detection of cracks.
    There are significant differences between the requirements under 
current rules for aircraft inspection/maintenance and the new 
requirements of the ``Aging Airplane Safety'' rule. Under current 
operation rules--with an exception \1\--there are no requirements for 
operators to accomplish a damage-tolerance based inspection program for 
any airplane; however, the FAA has mandated DT-SSIPs for large 
transport airplanes by the use of ADs. These ADs are applicable to the 
operators. The manufacturers agreed to provide DT-SSIPs to the 
operators. However, there is no rule mandating this, and it has been 
taking a long time for the manufacturers to develop the DT-SSIPs. 
Consequently, for some airplane models, there are various degrees of 
implementation of damage-tolerance-based standards, while for other 
airplane models, there is still no such implementation. For example, 
for the Boeing 757 and 767 models, it took 18 years for DT-based SSIPs 
to be implemented. The MD-80 model still does not have an implemented 
DT-based SSIP--after 18 years.
---------------------------------------------------------------------------

    \1\ '' That exception is the recently implemented rule on 
``Repair Assessment for Pressurized Fuselages,'' which requires 
damage-tolerance assessment of repairs to the fuselage pressure 
boundary of eleven aging, large transport airplane models.
---------------------------------------------------------------------------

    Currently, the inspection programs of small transport airplanes 
(such as DeHavilland/DHC-6) are not damage-tolerance based. Parts of 
these airplanes were certificated to either safe-life or fail-safe 
requirements. Under existing programs, that use these requirements, 
there are no provisions for inspections specifically focused on cracks. 
These inspection programs (which are provided by the original equipment 
manufacturer) involve a general visual inspection, but the mechanics 
may never look in areas that are hard to inspect visually--such as the 
horizontal stabilizer.
    In contrast to the current situation/rules, this final rule will 
require DT-based SSIPs within a reasonable length of time (4 years) 
after the effective date of the rule--so that all (part 121) transport 
airplanes will have DT-based SSIPs applicable for each model. Damage-
tolerance standards emphasize inspections and procedures to detect 
cracks at an early stage. These cracks can then be repaired. By 
contrast, the current inspection and maintenance programs of airplanes 
do not place special emphasis on cracks. Under the current system, the 
finding of cracks depends more on the quality of the particular 
mechanic doing the inspection, and on the particular inspection 
programs adopted by different airlines (or repair stations). 
Consequently, there is considerable variability in the detection of 
these cracks, across the U.S. commercial airplane fleet.

[[Page 72753]]

    The damage-tolerance-based program uses both non-invasive and 
invasive techniques to detect cracks on airplanes. By contrast, the 
current non-DT-based programs use simpler and fewer non-invasive 
techniques, and they do not use invasive techniques at all. The damage-
tolerance-based program uses (new) non-invasive technology--such as 
eddy current, ultrasonic waves, and magnetic particle inspections--to 
detect cracks, particularly small cracks. The existing non-DT-based 
maintenance programs do not require the use of these techniques; eddy 
current is used only if it is mandated by an AD for a previous cracking 
problem.
    Also, DT-based SSIPs implement inspections for fatigue ``hot 
spots''--that is, areas on the aircraft where cracks may develop. In 
this way, it will be possible for an airline to detect and follow the 
progress of these spots, or potential cracks, and repair them promptly.
    With regard to invasive techniques, the damage-tolerance-based 
inspections and procedures will mandate that operators of the affected 
airplanes inspect--by invasive techniques--in areas where that they 
probably would not have inspected before, such as the horizontal 
stabilizer. To get access to the stabilizer, operators may have to 
install access doors. Inside the horizontal stabilizer, there are ribs 
and spar caps that are covered by airplane skin. These components can 
crack without being detected by an inspection from the outside. A crack 
in a horizontal stabilizer can result in the loss of control of the 
aircraft--and lead to an accident.
    The comprehensive status of the U.S. airplane fleet with regard to 
cracking is fairly unknown. It is known that the fleet is aging and the 
metal of airplanes' structures is accumulating more flight cycles, 
resulting in an increasing risk of fatigue cracks and a catastrophic 
airplane accident. The current ad hoc approach relies heavily on 
airplane mechanics reporting cracks from visual inspections (leading to 
repairs). These inspections have resulted in the discovery of large 
cracks. If/when the discovery of cracks is deemed to be a serious 
problem, the FAA issues an AD for a particular model (and part of the 
airplane). In contrast to the current ad hoc approach, this rule will 
require all commercial airplanes to have damage-tolerance based SSIPs 
which include directed inspections for cracks.

Benefits

    The purpose of this rule is to play a key-role in assuring the 
continued structural airworthiness of air carrier airplanes as they 
continue in service. The rule puts into place one integral part of the 
FAA's ``Aging Aircraft Program'', initiated in 1988, to address the 
unique problems associated with older airplanes. This initiative was 
undertaken because significant numbers of air-carrier airplanes were, 
and are, continuing to operate beyond their original design service 
goals. The Aging Airplane Program was launched with participation by 
airplane operators and manufacturers, and with the specific goal of 
identifying maintenance procedures that are necessary beyond current 
requirements to deal with the phenomena of aging materials.
    After an extended period of working with industry's Airworthiness 
Assurance Task Force and the Airworthiness Assurance Working Group 
within the Aviation Regulatory Advisory Committee (ARAC), the FAA has 
concluded that four distinct areas of airplane aging need to be 
individually addressed. These areas are (1) fatigue cracking, (2) 
corrosion, (3) damage tolerance of structural repairs, and (4) 
widespread fatigue damage. Protection from fatigue cracking is the most 
generalized of these four areas, and was the first area of focus by the 
FAA. The agency issued a notice of proposed rulemaking on fatigue 
cracking on April 2, 1999, entitled ``Aging Airplane Safety''.
    Structural properties of materials change as a result of prolonged 
and/or repeated application of stress cycles on those materials. After 
some duration of cyclic stress, the material will fail under the 
applied load because of fatigue. One manifestation of fatigue in 
materials is cracking. In principal-structural elements of the 
airplane, cracking due to fatigue can result in a catastrophic failure 
of the aircraft. Left unchecked, it is not a question of whether the 
repeated loadings on aircraft will produce a major structural failure 
but, rather, when that failure will occur. At the time when the NPRM 
for this final rule was published, more than 29 percent of the 
airplanes affected by that proposal were already 20 years old or older; 
14 percent were over 30 years old; and 7 percent of the airplanes were 
over 40 years old. The average age of the U.S. airplane fleet has 
increased, in recent times, from 13.3 years in 1995 to 14.2 years in 
1999 (even with retirement of older airplanes).
    There is growing evidence of significant occurrence of fatigue 
cracks on airplanes and the potentially dire consequences of such 
cracks. This evidence includes: (1) The accident of the Aloha Boeing 
737-200, on April 28, 1988, when 18 feet of upper fuselage separated 
from the airplane in flight; and (2) the substantial, accumulated data 
showing the development of significant numbers of cracks on airplanes. 
In the Aloha accident, the National Transportation Safety Board 
determined the probable cause of the accident to be metal fatigue and 
corrosion. In addition, many cracks have been found over time on 
airplanes, including some that are quite long--thus, increasing the 
risk of accidents. These cracks are typically the result of fatigue 
from aging. The evidence of significant risk of airplane accidents as a 
result of cracks is described below, and includes: (1) A relative risk 
assessment, followed by (2) the record of Service Difficulty Reports, 
and ending with (3) a discussion of the Airworthiness Directives issued 
on fatigue and cracking for the U.S. commercial fleet.

Relative Risk Assessment

    This benefit analysis provides an estimate of the increasing 
relative risk of accidents over time, based upon existing data and some 
conservative assumptions. The FAA believes that the analysis results in 
a reasonable estimate of how much the accident risk, due to fatigue 
cracking, increases over time with aging aircraft, in the absence of 
the rule. The analysis is not an estimate of actual future accidents.
    To date, the airplane fleets affected by this rule have not 
experienced a fatigue-related accident, resulting in loss of life or 
serious injury, although the Aloha accident (mentioned previously) was 
partly attributed to the age of the airplane involved. The Aloha 
accident was followed by a series of ADs, on operators, whose 
successful implementation depended on the voluntary development of DT-
SSIPs by manufacturers. The development of these DT-SSIPs has been 
taking a relatively long time, and is still not completed. Moreover, 
numerous instances of serious cracking have been discovered among the 
fleet even during currently-required inspections that do not 
systematically investigate for fatigue cracking, as is required by this 
rule. This suggests that a fatigue problem does exist. An attempt is 
made here to provide an estimate of the magnitude of that problem--now 
and in the future.
    Based upon extensive testing, it is common engineering practice to 
assume that materials fail from fatigue according to a normal 
probability curve. The ``mean'' or highest point of the bell-shaped 
normal curve denotes the point at which half of the test samples have 
failed; or, stated another way, that is the point where the probability 
that any one

[[Page 72754]]

sample will have failed is one-half. Engineers often define ``Safe 
life'' as outside three standard deviations of the curve, to the left 
of the mean.
    An airplane is made up of a great many different and independent 
elements, each with its own failure characteristics. Consideration of 
the probabilities of time-to-failure resulting from fatigue for an 
entire airplane can be analyzed in terms of a normal distribution. The 
Central Limit Theorem allows the useful assumption that a plot of the 
means, of the various times-to-failure of a sufficient number of 
samples of individual parts of an airplane, will approximate a normal 
distribution, without regard to the actual underlying distribution of 
various times-to-failure of the parts. Using this approach, it can 
reasonably be assumed that in the absence of some preventive action, 
the fleet of aircraft affected by this rule would experience fatigue 
failure according to an approximately normal distribution curve. This 
analysis makes such as assumption. A normal curve is defined by its 
mean and standard deviation, and unfortunately neither of those numbers 
is known for the fleet of affected airplanes. As a result, a reasonably 
accurate failure curve cannot be constructed.
    However, by making some conservative assumptions, a curve of 
relative failure risk may be developed that could yield some useful 
indications. The relative risk curve would be identical to the actual 
failure curve if the failure curve could be identified. Therefore, the 
relative risk curve is also assumed to be approximately a normal 
distribution. The mean and standard deviation of this curve are also 
unknown. However, for the purpose of discussing relative risk, it is 
assumed that the mean of the relative risk curve is 50 years of age. 
That is to say, the probability of fatigue failure risk reaches 50 
percent at age 50, if no preventive action is taken. If the curve under 
discussion were an actual failure curve, it would mean that one-half of 
the fleet would have experienced fatigue failure by age 50 if no 
preventive actions were taken.
    For the purpose of discussing relative failure risk--not actual 
failure risk--it is assumed that the point of three standard deviations 
on the risk curve (to the left of the mean) occurs at the age of 14 
years. This matches the statutory requirement and the requirements of 
this rule that additional preventive actions be initiated at that time. 
Three standard deviations matches the often-used engineering convention 
that a component is ``safe'' outside that point (to the left of the 
mean).
    The curve is defined with a mean of 50 years and a standard 
deviation of 12 years ((50-14)/3). Interpolating from a standard normal 
probability table, the probabilities associated with such a curve by 
aircraft age are shown in Table 1. As previously stated, available data 
are not sufficient to claim that this table shows the fraction of the 
fleet that would experience fatigue failure with age, in the absence of 
this rule, but it may be a reasonable indicator of relative risks of 
failure for individual aircraft.
    A very small risk of failure occurs by age 14 years (0.001), as 
shown in Table 1. By age 22, however, the relative risk is ten times 
greater--one order of magnitude (at 0.01). By age 35, the risk of 
failure is one-hundred times greater, than that at age 14--two orders 
of magnitude (at 0.1). If the maximum, acceptable ``safe life'' risk 
occurs when an airplane reaches the point of three standard deviation 
from the mean, at 14 years of age, then this analysis indicates that 
this maximum acceptable risk is exceeded by one order of magnitude by 
age 22, and two orders of magnitude by age 35.
    A similar tabulation was done for relative probabilities of fatigue 
failure if the mean is assumed to be 62 years, instead of 50 years. (62 
years, instead of 60 or 65 years, was selected simply for ease of 
interpolation from the standard normal curve table.) In this case, the 
relative risk increases by one order of magnitude when an airplane 
reaches age 25 and two orders of magnitude by age 42.
    Although the above brief risk analysis is not precise and depends 
upon assumptions that could be varied, it does provide an idea of how 
the risk to aging aircraft increases over time. From this analysis, 
there is no question that over the years, the risk of fatigue failure 
for an airplane's structural parts increases. When the above analysis 
is applied to the fleet of airplanes affected by the rule, there is a 
strong indication that the level of safety from fatigue crack accidents 
has significantly declined. The analysis suggests that in the absence 
of the action proposed by this rule, the accident risk has increased 
beyond ``safe life'' by one order of magnitude when an aircraft reaches 
around 22 to 25 years of age. Over 25 percent of the fleet has reached 
or exceeded that age range. Further, the analysis suggests that the 
accident risk has increased to two orders of magnitude, beyond ``safe 
life'', in the 35 to 40 years of age range. Over 10 percent of the 
fleet has reached or exceeded that range.

     Table 1.--Relative Risk of Fatigue-Cracking Accident, With Age
                            [Mean = 50 years]
------------------------------------------------------------------------
                                           Relative     Age     Relative
               Age (years)                   risk     (years)     risk
------------------------------------------------------------------------
14......................................     0.0013        33     0.0793
15......................................     0.0018        34     0.0918
16......................................     0.0023        35     0.1056
17......................................     0.003         36     0.123
18......................................     0.0039        37     0.1401
19......................................     0.0049        38     0.1587
20......................................     0.0062        39     0.1814
21......................................     0.008         40     0.2033
22......................................     0.0099        41     0.2266
23......................................     0.0122        42     0.2546
24......................................     0.0154        43     0.281
25......................................     0.0188        44     0.3085
26......................................     0.0228        45     0.3409
27......................................     0.0281        46     0.3707
28......................................     0.0336        47     0.4013
29......................................     0.0401        48     0.4364
30......................................     0.0485        49     0.4681
31......................................     0.0571        50     0.5
32......................................     0.0668
------------------------------------------------------------------------

Service Difficulty Reports

    A review of Service Difficulty Reports (SDRs) shows that a 
significant problem exists with cracks on airplanes in the U.S. 
commercial fleet. SDRs are reports that provide information on the 
incidents (as opposed to accidents) of airplanes related to maintenance 
problems. The reports are typically completed by airline (or repair 
station) mechanics, and are then sent to, and collected by, the FAA. An 
objective of the submission and collection of SDRs is to track problems 
with aircraft parts and components. The findings of SDRs can lead to 
the issuing of airworthiness directives (ADs), when conditions observed 
are deemed to create a significant, adverse effect on air-transport 
safety.
    The FAA searched the National Aviation Safety Data Analysis Center 
(NASDAC) for service difficulty reports since 1990--for part 121 
airplanes--using three keywords: ``crack'', ``aging'', or ``fatigue''. 
The search resulted in over 94,000 records or SDRs. Of these, about 93 
percent, or 88,000 SDRs, were on ``cracks'' (while the remaining were 
on ``corrosion''). Eighty-eight thousand records are a significant 
number of problems involving aircraft cracks. These cracks were found 
on all the main parts of the airplane structure: fuselage, wings, and 
doors (of both passenger and cargo airplanes). Therefore, this 
assessment of SDRs shows a wide prevalence of cracks on U.S. commercial 
airplanes.

[[Page 72755]]

Airworthiness Directives

    Airworthiness Directives (ADs) are issued when serious problems 
with airplanes are discovered that--if not repaired--have a high 
likelihood of resulting in an accident. So, ADs are issued quickly in 
order to maintain the airworthiness of the affected airplanes and thus 
prevent accidents. Given the threat of an accident, when an AD is 
issued, operators have a limited time to resolve the problem and often 
require unscheduled maintenance.
    A tabulation was made of ADs issued by the FAA for problems with 
airframe ``fatigue'' and ``cracking''--for a recent period of less than 
one year: January 1 through September 2000. The results show that 56 
such ADs were issued by the FAA over that time period. These ADs apply 
to various parts of the airplane structure and these parts include: 
Fuselage, wings, door frames, deck floor beams, etc. A count of the 
affected parts indicates that:
    (1) Ten ADs were issued for cracks found on the fuselage skin;
    (2) Nine ADs were issued for cracks on wings;
    (3) Eight ADs were issued for cracks found on, and around, doors.
    (4) Eight ADs were issued for cracks found on (and around) 
bulkheads.
    (5) Two ADs were issued for cracks found on the tail assembly 
(which includes the horizontal and vertical stabilizers, and rudder).
    These Airworthiness Directives on cracks, also, affect all of the 
well-known airplane models. They include: Aerospatiale, Airbus, Boeing, 
Bombardier, British Aerospace, Dornier, Fairchild, Fokker, Lockheed, 
and McDonnell Douglas. Also, some of these ADs affect an entire 
airplane series. For example, an AD applies to the Airbus A-300 Series, 
while another AD refers to the Boeing 727 Series. Still another AD 
applies to the Boeing 737-200C Series, the Boeing 747 Series, and the 
Boeing 777 Series.
    If cracks are left undetected--and, thus, untreated--they grow. 
Subsequently, they can result in accidents. With regard to crack sizes 
and growth of cracks, one can refer--as an example--to the 
``Airworthiness Directive; Boeing Model 747 Series Airplanes'', Final 
rule; request for comments (Docket No. 2000-NM-206-AD). In the text of 
this AD, it is pointed out that ``The FAA has received reports that, 
during regular maintenance of certain Boeing Model 747 series 
airplanes, operators detected cracking of certain areas of the fuselage 
skin adjacent to the drag splice fitting. One operator reported finding 
four skin cracks, which ranged in length from 0.19 to 1.37 inches, 
under the drag splice fitting of the right side underwing. On another 
airplane, there was detection of a 8.5-inch long crack under the drag 
splice fitting of the left side. Moreover, another operator found a 25-
inch long diagonal crack between station (BS) 982 and BS 990 at 
stringers 37L through 38L.'' These data show the existence of 
different-size cracks found on different airplanes (of the same 
airplane model). The cracks (in this particular case) range in size 
from 0.19 inches to 25 inches. Therefore, these data indicate that 
under current inspection/maintenance procedures, which are not based on 
damage-tolerance standards, cracks have gone unnoticed and have become 
quite large.
    The text in the same AD goes on to emphasize the serious, potential 
consequences of cracks. It states that ``Such conditions, if not 
corrected, could result in reduced structural integrity of the 
fuselage, and consequent rapid depressurization of the airplane.'' 
Depressurization means that the fuselage of the aircraft is breached 
and that can result in an accident. When a fuselage is under pressure, 
if a crack gets long enough, it will fast fracture.\2\ When a crack 
fast fractures and is not arrested, the fuselage will experience a 
rapid depressurization event. Rapid depressurization can result in a 
number of serious adverse effects on the airplane and passengers. At 
best, after the airplane has suffered depressurization, the passengers 
ride in an unheated aircraft, breathe through oxygen masks, and hope 
for a safe landing. Another possible result, however, is an airplane 
accident. There are examples of catastrophic accidents occurring as a 
result of rapid depressurization; these accidents were not caused by 
cracks but they show the dire consequences of rapid depressurization. 
In one accident, in 1974, a DC-10 operated by Turkish Airlines, lost a 
door and had rapid depressurization. This caused the floor of the 
airplane to move and sever control cables--with catastrophic results. 
The accident killed 246 people. In another accident, in 1985, a B-747 
operated by Japan Airlines experienced a failure in the aft pressure 
bulkhead (from a bad repair). This affected the control system and the 
airplane crashed in a mountain--killing 524 people. It was very 
fortunate that the Aloha accident resulted in only one fatality.
---------------------------------------------------------------------------

    \2\ When a crack fractures at a rapid rate. A cleavage fracture 
may run as fast as 1 mile/second (1600 meters/second), a dimple 
fracture as fast as 1500 feet/second (500 meters/second), although 
it may be slower.
---------------------------------------------------------------------------

    Therefore, cracks are a serious airworthiness problem, as evidenced 
by the necessity to issue numerous ADs. These cracks have affected 
critical parts of the entire airplane structure across all the airplane 
types used in commercial aviation. The use of ADs is meant to address a 
specific problem during a specific time period. It is not an effective 
way to address a widespread problem that affects the entire U.S. 
commercial airline fleet--such as cracks. The ``Aging Airplane Safety'' 
rule provides a comprehensive and effective way to address that 
problem.
    In sum, it is accepted that after some duration of cyclic stress, 
metal will fail under applied load because of fatigue. From the 
relative risk assessment discussed above, it is clear that risk of 
metal fatigue increases by orders of magnitude as the airplanes age. 
Since 1990, there are over 88,000 airplane service difficulty reports 
that identify cracks found on all the main parts of airplane structure. 
There is not only abundant evidence of pervasive cracking in airplanes, 
but also many of these cracks have led to airworthiness problems. These 
risks are not acceptable. The FAA concludes that action must be taken 
to avoid this unacceptable risk. The inspections and records reviews 
required by this rule are expected to achieve the goal of maintaining 
an acceptable risk from fatigue cracking accidents.

Costs

Differences Between Costs of the NPRM and Final Rule

    There are several differences between preliminary regulatory 
evaluation of the NPRM and the final regulatory evaluation of the rule. 
Some of these differences reduce the costs of the rule, while others 
increase these costs. The net effect is for the estimated costs in the 
final regulatory evaluation to exceed substantially the costs estimated 
in the NPRM. These changes are explained in more detail below.
    The following changes from the NPRM to the final rule, based on 
information from public comments, reduced the cost of some requirements 
of the rule:
    (1) The time between repeat intervals was increased from 5 years to 
7 years--in order for the required inspections to be better 
accommodated by the schedule for heavy maintenance checks.
    (2) For airplanes that will be 25 years or more on the rule 
effective date, the time interval for the initial inspection was 
increased from 3 to 4 years.
    (3) In the final rule, operators of part 135 airplanes are exempt 
from damage-

[[Page 72756]]

tolerance inspections. Instead, they only need to implement a service-
history based SSIP--and that by 2010.
    (4) In the final rule, operations within Alaska are exempt from the 
rule's requirements.
    Despite the above factors that reduced costs, the estimated total 
cost of the rule in the final regulatory evaluation is significantly 
greater than the total cost of the rule estimated in the NPRM. This 
increased cost was affected by the following factors:
    (1) The number of affected airplanes was higher in the final 
regulatory evaluation. The number of part 121 airplanes that need DT 
SSIPs increased from 925 in the NPRM to 1,596 in the final regulatory 
evaluation.
    (2) For part 121 airplanes that have DT SSIPs, the cost estimation 
in the final rule increased the downtime for FAA/DAR inspections and 
records review to 2 days.
    (3) In the final regulatory evaluation, efficiency factors were not 
applied in the writing/development of damage-tolerance-based SSIPs.
    (4) The average airplane values used in the final regulatory 
evaluation were higher than those used in the preliminary regulatory 
evaluation. This results in increased downtime costs.
    As a result of the above changes, the total estimated cost of the 
rule increased from $99.6 million in the NPRM to $173.5 million in the 
final rule--in present value. The cost of the part 135 operators 
declined from $8.5 million to $1.7 million, in present value.
    Also, with respect to the distribution of the cost for inspections/
records review by FAA inspectors/DARs, in the final regulatory 
evaluation it was assumed that 60% of this activity will be conducted 
by DARs, while 40% will be conducted by FAA inspectors. In the NPRM, 
the cost methodology assumed that the cost of this activity would be 
shared 50%-50% between FAA inspectors and DARs. Consequently, the 
methodology of the final regulatory evaluation increased the cost of 
this activity for the operators.
    The rule will affect the operators of airplanes under part 121 that 
currently have (or are expected to have by 2004) damage-tolerance-based 
SSIPs incorporated into their maintenance program. In addition, those 
operators of airplanes under part 121 that are not currently required 
to incorporate a damage-tolerance-based SSIP into their maintenance 
program will need to develop such a program. The rule will also 
generate costs for operators of multi-engine airplanes that are 
operated in scheduled service under part 135 and initially certificated 
with 10 or more passenger seats. These operators are required to 
develop and implement damage-tolerance-based SSIPs by the year 2010. 
Many of the airplanes in this group have moved over time into part 121; 
consequently, their costs are measured through the part 121 airplane 
list.
    The rule will also generate costs for operators of multi-engine 
airplanes that are operated in scheduled service under part 135 and 
initially certificated with nine or fewer passenger seats. These 
operators are required, by the final rule, to develop and implement 
service-history-based SSIPs by the year 2010. Service-history-based 
SSIPs have considerably lower costs than damage-tolerance-based SSIPs. 
In the NPRM, the proposed rule required that the operators of these 
airplanes also implement damage-tolerance-based SSIPs. However, as a 
result of public comments and additional consideration, this final rule 
exempts those airplanes from damage-tolerance-based SSIPs and, instead, 
requires the lower-cost service-history-based SSIPs.
    The estimated costs of this rule do not include the expenses of 
making repairs to airplanes that may be found necessary during either 
the SSIP-directed inspections, conducted by the airplane mechanics, or 
the oversight inspections conducted by the FAA inspectors or DARs. 
While the FAA recognizes that such repairs can sometimes constitute a 
considerable expense, the costs of these repairs are not attributable 
to this rule because existing FAA regulations require that repairs be 
made to assure the continued airworthiness of the airplane.
    Also, the economic evaluation focuses on existing airplanes and 
does not address the costs that the rule will eventually impose on 
newly-produced airplanes. The requirements of this rule on newly-
produced airplanes are beyond (or nearly so) the 20-year time period of 
this study. Consequently, these costs, particularly their present 
value, are expected to constitute a relatively small proportion of the 
costs calculated in this study.

Costs for Part 121 Airplanes That Have Damage-Tolerance-Based SSIPs

    For those part 121 operators that have (or will have by 2004) a 
damage-tolerance-based SSIP, the rule will not impose costs for damage-
tolerance-based inspections conducted by their mechanics or for 
downtime of airplanes caused by these inspections. The rule will 
require that these airplanes implement inspections and records reviews 
by FAA inspectors or Designated Airworthiness Representatives (DARs), 
at designated time intervals. This requirement will result in 
additional costs for the affected operators. These inspections/records 
review are expected to result in additional time that an airplane is 
out-of-service. While this downtime cost estimates in the NPRM were 
based on loss-of-service estimates that ranged from 0.7 to 1.6 days per 
airplane inspection, in these cost calculations, the downtime has been 
increased to 2.0 days. This increase in downtime reflects the input of 
public comments.
    The estimated cost of airplane downtime is based on a rate of 
return to capital approach, in which the operational airplane is the 
productive capital and there is a return associated with its use. 
Consequently, out-of-service cost can be estimated through the loss of 
capital services of the aircraft. The value of this loss is measured by 
the rate of return to capital (aircraft). This analysis uses 7 percent 
per annum as the average rate of return to capital; this rate is also 
preferred by the Office of Management and Budget for present-value 
calculations. Consequently, downtime costs were calculated as the 
product of the 2 downtime days, divided by 365 days (per year), 
multiplied by the rate-of-return to capital, at 7 percent. The 
resulting estimate is a downtime cost per airplane (in a model group), 
per inspection. To obtain the cost of downtime for a model group, the 
downtime cost per airplane is multiplied by the number of airplanes in 
that model group. The total downtime cost of the rule is the summation 
across model groups and over time. Thus, the estimate for downtime 
costs, for part 121 airplanes with damage-tolerance-based SSIPs over 
the period of analysis, is $98.4 million, undiscounted. Assuming an 
average of two inspections per airplane over the 20-year period of 
analysis, and using 7,620 airplanes and 2 days per inspection, one 
estimates downtime costs at $3,228 per day per airplane (undiscounted).
    This figure (of $3,228 per day) is significantly different/lower 
than figures provided by some public comments of $80,000 in lost 
revenue per inspection which--given a two-day downtime period--would 
result in $40,000 lost revenue per day. On should note that the 
relevant variable to measure for downtime cost is lost net income--that 
is, ``revenue minus costs'' of operating the airplane. And lost net 
income would be substantially lower than lost revenue per day for an 
airplane. When an airplane is out-of-service, there is loss of revenue 
but costs of operation are also

[[Page 72757]]

not incurred (pilot salaries, fuel, maintenance, etc.).
    There were also adjustments to these cost estimates. The estimated 
total cost of the rule, for this group of airplanes, was computed under 
the hypothesis that all of the affected airplanes that exist today will 
continue to be operating through the end of the study period--year 
2020. In actuality, however, over time there will be normal replacement 
and retirement, by operators of these airplanes. Consequently, a 
substantial portion of these costs will not be incurred. The evaluation 
assumes that at least one-third of the potential $245.0 million costs 
will not be incurred due to normal replacement and retirement of 
aircraft. This assumption is the same as that used in the initial 
regulatory evaluation.

Cost of the Rule for Part 121 Airplanes That Need To Incorporate 
Damage-Tolerance-Based SSIPs Into Their Maintenance Program

Steps in Cost Estimation
    The relevant tasks and associated costs of the rule for these 
airplanes include:
    (1) Development of the damage-tolerance-based SSIP.
    (2) Incorporation of damage-tolerance-based SSIPs into operators' 
maintenance programs.
    (3) Review/approval by FAA of operators' damage-tolerance-based 
SSIP and of their incorporation into the operators' maintenance 
programs.
    (4) Modification costs.
    (5) Inspections--conducted by airline mechanics.
    (6) Downtime costs for airplanes for inspections--by airline 
mechanics.
    (7) Cost for operator personnel to prepare the airplane and its 
records for the FAA inspector or DAR, to conduct their inspection and 
records review.
    (8) Direct costs for FAA inspectors/DARs, to conduct inspections 
and records reviews of the affected airplanes.
    (9) Downtime cost of airplane for the above inspection and records 
review by FAA/DARs.
    With regard to the downtime costs of airplanes for inspections by 
mechanics, the evaluation assumes that each 40 hours of inspection 
work, caused by this rule, will require one additional day of airplane 
downtime. The methodology again uses the rate of return to capital 
approach, with 7 per cent per year. Consequently, the cost of aircraft 
downtime, for mechanic inspections, for the affected airplanes over the 
period of analysis is estimated at $3.1 million, undiscounted.
    With regard to the downtime costs of these airplanes for 
inspection/records review by FAA/DARs, the additional downtime is 
estimated to range between 0.7 and 1.6 days per airplane inspection --
depending on airplane value. Subsequently, the cost of downtime is 
calculated by the rate of return to capital approach (using 7 percent). 
The result is an estimate of $702,000 undiscounted, for downtime costs 
of the affected airplanes.

Adjustments to Cost Estimates

    For some models, the potential cost of complying with the 
requirements of the rule could constitute a significant proportion of 
(or may actually exceed) the economic values of the airplanes involved. 
Consequently, for each airplane model group, the estimated potential 
cost of compliance was compared with the estimated economic value of 
the airplanes in that model group. In cases where the potential 
compliance cost exceeds 50 percent of the group value, the methodology 
assumes that an SSIP will not be developed and implemented. 
Consequently, the related compliance costs for the rule will not be 
incurred. Instead, it is expected that the affected models will be 
retired or transferred out of scheduled service. The estimated forced 
out-of-service costs for these models are estimated to be 50 percent 
reduction in their economic value.
    However, this (apparent) reduction in the cost of the rule is 
accompanied by an increase in another type of cost. This includes the 
hardship and economic dislocation that will result from the reduction 
in operations, or by possibly going out of business, by some operators. 
This hardship can include the loss of jobs by employees of the affected 
operators, and the subsequent negative effects of this on themselves 
(their households) and their communities. These costs are recognized 
although not quantified.

Other Adjustments to the Cost Estimates

    The estimated cost of the rule for this group of airplanes was 
computed under the scenario whereby all of the affected airplanes that 
exist today will continue to fly through the end of the study period 
(year 2020). In actuality, however, there will be normal replacement 
and retirement of these airplanes (by operators) and, consequently, a 
substantial portion of these costs will not be incurred. The 
replacement cycle for this group of airplanes can vary widely. For some 
mainstream scheduled commuter carriers, it is common practice for 
airplanes to be routinely replaced. In a number of cases, few if any of 
the costs of this rule will be incurred. Conversely, the economics of 
some smaller, or niche carriers, are such that airplanes may continue 
to fly for 40 years or more. Given available information, the 
evaluation assumes that at least one-third of the potential $163.8 
million costs will not be incurred, as a result of normal replacement/
retirement of airplanes--leaving an estimated cost of $104.4 million.

Part 135 Airplanes

    This final rule exempts certain part 135 airplanes from 
implementing DT-based SSIPs. These are multi-engine airplanes, operated 
in scheduled service, initially certificated with nine or fewer 
passengers. Instead of a DT SSIP, the operators of these airplanes will 
have to implement a service-history-based SSIP--by the year 2010. A 
service-history-based SSIP is estimated to cost significantly less than 
a damage-tolerance-based SSIP--in general, 0.20 of the cost of a DT-
based SSIP. The cost of the rule for this group of airplanes is 
estimated at $1.7 million, discounted ($2.9 million, undiscounted).

Costs to the FAA

    The rule is also estimated to have costs of $91.0 million 
undiscounted to the FAA. Virtually, the entire amount of these costs is 
for FAA inspectors to conduct inspections and records review. This cost 
estimate is based on the assumption that 40 percent of the inspections/
records review will be conducted by the FAA inspectors while 60 percent 
will be conducted by DARs.
    Table 2 presents the total costs of the rule, over the period of 
analysis--for the operators (and manufacturers) of the affected 
airplanes and the FAA. Total costs are estimated at $362.9 million, 
undiscounted, with a present value of $173.5 million.

[[Page 72758]]



                                        Table 2.--Total Cost of the Rule
                                        [Dollars in millions, 2001-2020]
----------------------------------------------------------------------------------------------------------------
                                                                                  Undiscounted      Discounted
                                                                                     costs            costs
----------------------------------------------------------------------------------------------------------------
Operators of airplanes that have damage-tolerance-based SSIPs.................           $164.1            $72.2
Operators of airplanes that need damage-tolerance-based SSIPs.................            104.9             59.6
Operators of airplanes that need service-history-based SSIPs..................              2.9              1.7
FAA costs.....................................................................             91.0             40.0
                                                                               ------------------
      Total Costs.............................................................            362.9            173.5
----------------------------------------------------------------------------------------------------------------

Comparison of Costs and Benefits

    The changes required by the rule are necessary to ensure the 
continuing airworthiness of aging airplanes. The FAA finds that the 
expected benefits of the rule justify its costs. The total estimated 
costs of the rule are $173.5 million, discounted ($362.9 million, 
undiscounted). The benefits have been assessed through several 
perspectives as explained below.
    There is growing evidence of significant occurrence of fatigue 
cracks on airplanes and the potentially dire consequences of such 
cracks. The evidence of significant risk of airplane accidents, as a 
result of cracks, include: (1) The Aloha accident; (2) the results of 
the relative risk assessment; (3) the number of Service Difficult 
Reports on cracks; and (4) the Airworthiness Directives issued for 
fatigue and cracking on the U.S. commercial aviation fleet.
    The relative risk assessment showed that while a small risk of 
failure--due to fatigue cracks--exists by year 14 of an airplane's 
service life, by age 22, that risk is 10 times greater (one order of 
magnitude). Furthermore, by age 35, the risk is 100 times greater than 
at age 14 (two orders of magnitude). Over 25 percent of the fleet has 
reached or exceeded the range of 22 to 25 years of age. Over 10 percent 
of the fleet has reached or exceeded 35 years of age.
    In addition, a search resulted in 88,000 Service Difficulty Reports 
on cracks, since 1990. This number of records indicates a prevalent and 
significant problem with cracks in the aircraft fleet. Furthermore, the 
significant number of ADs on cracks on airplanes--issued during a 
recent period (of less than a year) also indicates the existence of a 
serious problem with cracks on the U.S. commercial fleet. ADs are 
issued quickly to remedy problems that have a high likelihood of 
resulting in accidents. Each AD, by itself, is proof that a significant 
accident risk exists.
    Therefore, based on the above evidence, the FAA finds that the 
expected benefits of this rule justify its expected costs.

Regulatory Flexibility Analysis

    The Regulatory Flexibility Act of 1980 (RFA) establishes ``as a 
principle of regulatory issuance that agencies shall endeavor, 
consistent with the objective of the rule and of applicable statutes, 
to fit regulatory and informational requirements to the scale of the 
business, organizations, and governmental jurisdictions subject to 
regulation.'' To achieve that principle, the Act requires agencies to 
solicit and consider flexible regulatory proposals, and to consider the 
rationale for their actions. The Act covers a wide range of small 
entities, including small businesses, not-for-profit organizations and 
small governmental jurisdictions.
    Agencies must perform a review to determine whether a proposed or 
final rule will have a significant economic impact on a substantial 
number of small entities. If the determination is that it will have 
such an impact, the agency must prepare a regulatory flexibility 
analysis as described in the Act. However, if an agency determines that 
a proposed, or final, rule is not expected to have a significant 
economic impact on a substantial number of small entities, section 
605(b) of the 1980 act provides that the head of the agency may so 
certify and a regulatory flexibility analysis is not required. The 
certification must include a statement providing the factual basis for 
this determination, and the reasoning should be clear.
    For the NPRM, the FAA conducted a complete initial regulatory 
flexibility analysis to assess the impact on small entities. This rule 
will affect commercial operators of airplanes, in the specified part of 
the CFR. For these operators, a small entity is defined as one with 
1,500 or fewer employees. As there are operators that met that criteria 
for a small business, calculations were carried out to assess whether 
the rule will have a significant impact on a substantial number of 
these operators.

Issues Addressed in the Final Regulatory Flexibility Analysis (FRFA)

    The central focus of the FRFA, like the Initial Regulatory 
Flexibility Analysis (IRFA), is the requirement that agencies evaluate 
the impact of a rule on small entities and analyze regulatory 
alternatives that minimize the impact when there will be a significant 
economic impact on a substantial number of small entities.
    The requirements, outlined in section 604(a)(1-5), are listed and 
discussed below:
    (1) A succinct statement of the need for, and objectives of, the 
rule.--This rule represents a critical step toward compliance with the 
Aging Aircraft Safety Act of 1991. Section 44717 of title 49 instructs 
the Administrator to ``prescribe regulations that ensure the continuing 
airworthiness of aging aircraft.'' The law also requires the 
Administrator to make inspections, and review the maintenance and other 
records, of each aircraft an air carrier uses to provide air 
transportation. The objectives of the rule is to ensure the continuing 
airworthiness of aging airplanes operating in air transportation.
    (2) A summary of the significant issues raised by the public 
comments in response to the IRFA, a summary of the agency's assessment 
of such issues, and a statement of any changes made in the proposed 
rule as a result of such comments.--There were very few public comments 
explicitly on the Initial Regulatory Flexibility Analysis. There were a 
substantial number of comments from part 135 operators that complained 
about the financial burden that the proposed rule would place on them. 
Small commercial operators (less than 1,500 employees) come from this 
group, as well as from part 121 operators.
    In response to public comments, the FAA made several changes to the 
final rule:
    (i) The primary change is that part 135 airplanes operating in 
scheduled operations, initially certificated with nine passenger seats 
or less, are exempted from implementing damage-tolerance-based SSIPs. 
Instead, they are

[[Page 72759]]

to implement service-history-based SSIPs--and those by 2010. The SH 
SSIPs are estimated to cost 20 percent of the cost of a DT SSIP (to 
develop and implement).
    (ii) The interval between repeat inspections was extended in the 
final rule to seven years, from five years in the NPRM.
    (iii) For the initial inspection, the interval from the effective 
date of the rule was extended from 3 to 4 years for airplanes greater 
than 25 years old.
    (3) A description of, and an estimate of, the number of small 
entities to which the rule will apply or an explanation of why no such 
estimate is available.--The FAA estimated the number and input of small 
entities as follows. First, small operators in part 121 were selected, 
by using a database that listed part 121 operators, with their number 
of employees and annual revenue. This database came from a study on 
small business done for the FAA by a consulting firm (GRA, 
Incorporated). The search identified 58 operators with 1500 or fewer 
employees, and with known annual revenue. Then, airplanes of these 
operators were identified--by using data from the BACK database. This 
search identified small entities operating under part 121, with 
affected airplanes (those in part 121 that had DT SSIPs and those that 
need DT SSIPs).
    Next, the net present value of the cost of the rule was calculated 
for each operator. As these cost calculations are based on airplane 
model groups, the resulting net present value (NPV) for one airplane is 
obtained by dividing the cost of the group by the total number of 
airplanes in that group. The result is an ``average'' net present value 
per airplane. The NPV per airplane is then multiplied by the number of 
airplanes of that operator, in that model group. If there is more than 
one model group, per operator, the NPVs of the model groups are summed 
to derive the net present value of the cost of this rule for the 
affected operators. Subsequently, these discounted costs are used to 
derive annualized costs, for each affected small operator.
    With respect to part 135 operators, a search was made in the GRA 
database that listed part 135 operators, along with the number of 
employees and annual revenues per firm. The identified small operators 
were then checked against a database of the FAA which listed the names 
of part 135 operators and their airplanes. This search identified 26 
small entities operating under part 135, including two operators that 
operate under parts 135 and 121. For part 135 operators, the net 
present value of the rule's cost and annualized cost were derived in 
the same manner as for part 121 operators.
    Annualized costs for the affected operators were then divided by 
annual revenues of the operators. The results show that for all--except 
two--of the listed 58 small operators, under part 121, the ratio of 
annualized cost to revenues is substantially less than one percent. For 
one operator, the ratio is 5.9 percent, while for another operator, it 
is 1.1 percent. With regard to part 135 operators, of the 24 identified 
operators, all but two show a ratio of annualized cost to annual 
revenue that is less than one percent. Thus, of the 82 identified small 
operators--under part 121 and/or part 135--all except four have a ratio 
of annualized cost to annual revenue that is substantially less than 
one percent.
    (4) A description of the projected reporting, record-keeping, and 
other compliance requirements of the rule, including an estimate of the 
classes of small entities which will be subject to the requirement and 
the type of professional skills necessary for preparation of the report 
or record.--In order for the FAA to fulfill its obligation under 49 
U.S.C. 44717, this rule will require that certain records be made 
available by the operator. Most of the records that will be required 
under this rule for part 121 airplanes are currently required by other 
regulations. Consequently, there is expected to be a minimal additional 
paperwork, for these airplanes, as a result of the rule. Concerning 
part 135 airplanes, their exemption from DT SIPPs is expected not to 
result in additional paperwork for their operators.
    (5) A description of the steps the agency has taken to minimize the 
significant economic impact on small entities consistent with the 
stated objectives of applicable statutes, including a statement of the 
factual, policy, and legal reasons for selecting the alternative 
adopted in the final rule and why each one of the other significant 
alternatives to the rule considered by the agency which affect the 
impact on small entities was rejected.--In order to decrease the cost 
burden for the final rule, the FAA will exempt operators of part 135 
airplanes from implementing damage-tolerance-based (DT) SSIPs. These 
operators are nearly all small entities. Instead of the DT-based SSIP 
requirement, these operators' aircraft will be subject to a Service-
History (SH)-based supplemental inspection program to be implemented by 
the year 2010. The SH-based SSIP is estimated to be 20 percent of the 
cost of a DT-based SSIP.
    Furthermore, in its efforts to assist small entities and other 
affected parties operating part 135 airplanes, the FAA will publish 
(with the final rule) an advisory circular, AC 91-60A ``The Continued 
Airworthiness of Older Airplanes''.

Description of Alternatives

    The FAA has considered several alternative approaches to this 
rulemaking and has attempted to minimize the potential economic impact 
of the rule, especially the impact on the operation of aircraft most 
likely to be used by small entities. At the same time, the agency needs 
to meet its primary responsibility for aviation safety and its 
particular obligation under 49 U.S.C. 44717 to ensure the continuing 
airworthiness of aging aircraft.
    The FAA made two changes to the requirements of the final rule that 
significantly lower compliance costs of operators. First, the FAA chose 
to lengthen the time period between inspections from 5 to 7 years. This 
longer period lowers the compliance cost of the affected operators as 
the inspections can occur at a heavy maintenance check. Second, the FAA 
exempted part 135 operators from the most expensive requirement of the 
rule. Part 135 operators are nearly all small entities.

Compliance Assistance

    In its efforts to assist small entities and other affected parties 
in complying with the rule, the FAA will be publishing two advisory 
circulars (for comment) with the final rule. One is AC 91-56B 
``Continuing Structural Integrity Program for Airplanes'' and it will 
provide guidance for complying with a DT SSIP. The other document is AC 
91-60A ``The Continued Airworthiness of Older Airplanes'', which will 
provide guidance for complying with a service-history based SSIP. These 
circulars will be published concurrently with this rule, with a request 
for comments.

International Trade Impact Analysis

    The Trade Agreement Act of 1979 prohibits Federal agencies from 
engaging in any standards or related activities that create unnecessary 
obstacles to the foreign commerce of the United States. Legitimate 
domestic objectives, such as safety, are not considered unnecessary 
obstacles. The statute also requires consideration of international 
standards and where appropriate, that they be the basis for U.S. 
standards.
    In accordance with the above statute, the FAA has assessed the 
potential affect of this final rule and has determined that it will 
impose the same costs on domestic and international

[[Page 72760]]

entities and thus will have a neutral trade impact.

Unfunded Mandates Analysis

    Title II of the Unfunded Mandates Reform Act of 1995 (the Act), 
enacted as Pub. L. 104-4 on March 22, 1995, requires each Federal 
agency, to the extent permitted by law, to prepare a written assessment 
of the effects of any Federal mandate, in a proposed or final agency 
rule, that may result in an expenditure by State, local, and tribal 
governments, in the aggregate, or by the private sector, of $100 
million or more (adjusted annually for inflation) in any one year. 
Section 204(a) of the Act, 2 U.S.C. 1534(a), requires the Federal 
agency to develop an effective process to permit timely input by 
elected officers (or their designees) of State, local, and tribal 
governments on a proposed ``significant intergovernmental mandate.'' A 
``significant intergovernmental mandate'' under the Act is any 
provision in a Federal agency regulation that will impose an 
enforceable duty upon State, local, and tribal governments, in the 
aggregate, of $100 million (adjusted annually for inflation) in any one 
year. Section 203 of the Act, 2 U.S.C. 1533, which supplements section 
204(a), provides that before establishing any regulatory requirements 
that might significantly or uniquely affect small governments, the 
agency shall have developed a plan that, among other things, provides 
for notice to potentially affected small governments, if any, and for a 
meaningful and timely opportunity to provide input in the development 
of regulatory proposals.
    This rule does not contain a Federal intergovernmental or private 
sector mandate that exceeds $100 million in any one year.

Paperwork Reduction Act

    Information collection requirements in the final rule have been 
previously approved by the Office of Management and Budget (OMB) under 
the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 
3507(d)) and have been assigned OMB Control Numbers: 2120-0020-, 2120-
0008, and 2120-0039. Part 129 record requirements can be found in 
International Civil Aviation Organization Annexes.

International Compatibility

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to comply with 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. The FAA 
determined that there are no ICAO Standards and Recommended Practices 
that correspond to these regulations.

International Trade Impact Analysis

    The Trade Agreement Act of 1979 prohibits Federal agencies from 
engaging in any standards or related activities that create unnecessary 
obstacles to the foreign commerce of the United States. Legitimate 
domestic objectives, such as safety, are not considered unnecessary 
obstacles. The statute also requires consideration of international 
standards and, where appropriate, that they be the basis for U.S. 
standards. In addition, consistent with the Administration's belief in 
the general superiority and desirability of free trade, it is the 
policy of the Administration to remove or diminish, to the extent 
feasible, barriers to international trade. This includes both barriers 
affecting the export of American goods and services to foreign 
countries, and barriers affecting the import of foreign goods and 
services into the United States.
    In accordance with the above statute and policy, the FAA has 
assessed the potential effect of this final rule and has determined 
that it will impose the same costs on domestic and international 
entities, and thus will have a neutral trade impact.

Unfunded Mandates Analysis

    Title II of the Unfunded Mandates Reform Act of 1995 (the Act), 
enacted as Public Law 104-4 on March 22, 1995, requires each Federal 
agency, to the extent permitted by law, to prepare a written assessment 
of the effects of any Federal mandate, in a proposed or final agency 
rule, that may result in an expenditure by State, local, and tribal 
governments, in the aggregate, or by the private sector, of $100 
million or more (adjusted annually for inflation) in any one year. 
Section 204(a) of the Act, 2 U.S.C. 1534(a), requires the Federal 
agency to develop an effective process to permit timely input by 
elected officers (or their designees) of State, local, and tribal 
governments on a proposed ``significant intergovernmental mandate.'' A 
``significant intergovernmental mandate'' under the Act is any 
provision in a Federal agency regulation that will impose an 
enforceable duty upon State, local, and tribal governments, in the 
aggregate, of $100 million (adjusted annually for inflation) in any one 
year. Section 203 of the Act, 2 U.S.C. 1533, which supplements section 
204(a), provides that before establishing any regulatory requirements 
that might significantly or uniquely affect small governments, the 
agency shall have developed a plan that, among other things, provides 
for notice to potentially affected small governments, if any, and for a 
meaningful and timely opportunity to provide input in the development 
of regulatory proposals.
    This rule does not contain a Federal intergovernmental or private 
sector mandate that exceeds $100 million in any one year.

Executive Order 13132, Federalism

    The FAA has analyzed this final rule under the principles and 
criteria of Executive Order 13132, Federalism. We determined that this 
action will not have a substantial direct effect on the States, or the 
relationship between the national Government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government. Therefore, we determined that this final rule does not have 
federalism implications.

Environmental Analysis

    FAA Order 1050.1D defines FAA actions that may be categorically 
excluded from preparation of a National Environmental Policy Act (NEPA) 
environmental impact statement. In accordance with FAA Order 1050.1D, 
appendix 4, paragraph 4(j), this rulemaking action qualifies for a 
categorical exclusion.

Energy Impact

    The energy impact of the notice has been assessed in accordance 
with the Energy Policy and Conservation Act (EPCA) Public Law 94-163, 
as amended (42 U.S.C. 6362), and FAA Order 1053.1. It has been 
determined that the final rule is not a major regulatory action under 
the provisions of the EPCA.

List of Subjects

14 CFR Part 119

    Air carriers, Air transportation, Aircraft, Aviation safety, 
Commuter operations, Reporting and recordkeeping requirements.

14 CFR Part 121

    Air carriers, Aircraft, Aviation safety, Reporting and 
recordkeeping requirements, Safety, Transportation.

14 CFR Part 129

    Air carriers, Aircraft, Aviation safety, Reporting and 
recordkeeping requirements.

14 CFR Part 135

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

[[Page 72761]]

14 CFR Part 183

    Aircraft, Authority delegations (Government agencies), Reporting 
and recordkeeping requirements.

The Amendment

    In consideration of the foregoing, the Federal Aviation 
Administration amends parts 119, 121, 129, 135, and 183 of title 14, 
Code of Federal Regulations as follows:

PART 119--CERTIFICATION: AIR CARRIERS AND COMMERCIAL OPERATORS

    1. The authority citation for part 119 continues to read as 
follows:

    Authority: 49 U.S.C. 106(g), 1153, 40101, 40102, 40103, 40113, 
44105, 44106, 44111, 44701-44717, 44722, 44901, 44903, 44904, 44906, 
44912, 44914, 44936, 44938, 46103, 46105.


    2. Amend Sec.  119.3 by adding the definition of ``years in 
service'' after the definition of ``When common carriage is not 
involved or operations not involving common carriage'' to read as 
follows:


Sec.  119.3  Definitions.

* * * * *
    Years in service means the calendar time elapsed since an aircraft 
was issued its first U.S. or first foreign airworthiness certificate.

PART 121--OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL 
OPERATIONS

    3. The authority citation for part 121 continues to read as 
follows:

    Authority: 49 U.S.C. 106(g), 40113, 40119, 44101, 44701-44702, 
44705, 44709-44711, 44713, 44716-44717, 44722, 44901, 44903-44904, 
44912, 46105.


    4. Add Sec.  121.368 to read as follows:


Sec.  121.368  Aging airplane inspections and records reviews.

    (a) Applicability. This section applies to all airplanes operated 
by a certificate holder under this part, except for those airplanes 
operated between any point within the State of Alaska and any other 
point within the State of Alaska.
    (b) Operation after inspection and records review. After the dates 
specified in this paragraph, a certificate holder may not operate an 
airplane under this part unless the Administrator has notified the 
certificate holder that the Administrator has completed the aging 
airplane inspection and records review required by this section. During 
the inspection and records review, the certificate holder must 
demonstrate to the Administrator that the maintenance of age-sensitive 
parts and components of the airplane has been adequate and timely 
enough to ensure the highest degree of safety.
    (1) Airplanes exceeding 24 years in service on December 8, 2003; 
initial and repetitive inspections and records reviews. For an airplane 
that has exceeded 24 years in service on December 8, 2003, no later 
than December 5, 2007, and thereafter at intervals not to exceed 7 
years.
    (2) Airplanes exceeding 14 years in service but not 24 years in 
service on December 8, 2003; initial and repetitive inspections and 
records reviews. For an airplane that has exceeded 14 years in service 
but not 24 years in service on December 8, 2003, no later than December 
4, 2008, and thereafter at intervals not to exceed 7 years.
    (3) Airplanes not exceeding 14 years in service on December 8, 
2003; initial and repetitive inspections and records reviews. For an 
airplane that has not exceeded 14 years in service on December 8, 2003, 
no later than 5 years after the start of the airplane's 15th year in 
service and thereafter at intervals not to exceed 7 years.
    (c) Unforeseen schedule conflict. In the event of an unforeseen 
scheduling conflict for a specific airplane, the Administrator may 
approve an extension of up to 90 days beyond an interval specified in 
paragraph (b) of this section.
    (d) Airplane and records availability. The certificate holder must 
make available to the Administrator each airplane for which an 
inspection and records review is required under this section, in a 
condition for inspection specified by the Administrator, together with 
records containing the following information:
    (1) Total years in service of the airplane;
    (2) Total flight hours of the airframe;
    (3) Total flight cycles of the airframe;
    (4) Date of the last inspection and records review required by this 
section;
    (5) Current status of life-limited parts of the airframe;
    (6) Time since the last overhaul of all structural components 
required to be overhauled on a specific time basis;
    (7) Current inspection status of the airplane, including the time 
since the last inspection required by the inspection program under 
which the airplane is maintained;
    (8) Current status of the following, including the method of 
compliance:
    (i) Airworthiness directives;
    (ii) Corrosion Prevention and Control Programs; and
    (iii) Inspections and procedures required by Sec.  121.370a of this 
part;
    (9) A list of major structural alterations; and
    (10) A report of major structural repairs and the current 
inspection status for those repairs.
    (e) Notification to Administrator. Each certificate holder must 
notify the Administrator at least 60 days before the date on which the 
airplane and airplane records will be made available for the inspection 
and records review.

    5. Add Sec.  121.370a to read as follows:


Sec.  121.370a  Supplemental inspections.

    (a) Applicability and general requirements. After December 5, 2007, 
a certificate holder may not operate an airplane under this part unless 
the maintenance program for that airplane includes damage-tolerance-
based inspections and procedures. Paragraphs (b), (c), and (d) of this 
section list the exceptions to this requirement. This section does not 
apply to an airplane operated by a certificate holder under this part 
between any point within the State of Alaska and any other point within 
the State of Alaska.
    (b) New model added through type certificate amendment. This 
paragraph applies to each airplane added to a type certificate after 
December 8, 2003, that has a certification basis that does not include 
a requirement for damage-tolerance-based inspections and procedures. A 
certificate holder may not operate that airplane more than 4 years 
after the date of the type certificate amendment unless the maintenance 
program for that airplane includes damage-tolerance-based inspections 
and procedures.
    (c) Design-life goal airplanes. If on or after December 5, 2007, 
the time in service of an airplane reaches the design-life goal listed 
in appendix N to this part, the certificate holder may operate that 
airplane until the date the airplane's time in service reaches the 
design-life goal or until December 20, 2010, whichever occurs sooner. 
After that date, the certificate holder may not operate the airplane 
unless the maintenance program for that airplane includes damage-
tolerance-based inspections and procedures.
    (d) Airworthiness directive-mandated service-history-based 
inspections. Until December 20, 2010, a certificate holder may operate 
an airplane for which an airworthiness directive requires the 
maintenance program to include service-history-based inspections and 
procedures. After that date, the certificate holder may not operate the 
airplane unless the maintenance program for that airplane includes 
damage-tolerance-based inspections and procedures.
    (e) Approvals. The inspections and procedures required by this 
section to

[[Page 72762]]

be included in the certificate holder's maintenance program for an 
airplane must be approved by the FAA Aircraft Certification Office or 
office of the Small Airplane Directorate or Transport Airplane 
Directorate having cognizance over the type certificate for the 
affected airplane.

    6. Add appendix N to part 121 to read as follows:

                                   Appendix N to Part 121.--Design-Life Goals
----------------------------------------------------------------------------------------------------------------
                                                 Number of                                          Design-life
                Airplane type                      seats          Type certificate data sheet      goal (hours)
----------------------------------------------------------------------------------------------------------------
Raytheon (Beech) Aircraft Co.:
    --Beech 99 (all models).................            15+2  A14CE.............................          46,000
    --Beech 1900 and 1900C..................            19+2  A24CE.............................          45,000
    --Beech 300 and 300LW...................            13+2  A24CE.............................          30,000
    --Beech B300 and B300C..................            15+2  A24CE.............................          30,000
    --Beech 1900D...........................            19+2  A24CE.............................          45,000
British Aerospace Ltd.:
    --BAe Jetstream 3101....................            19+2  A21EU.............................          45,000
    --BAe Jetstream 3201....................            19+2  A56EU.............................          30,000
deHavilland Aircraft Co.: DHC-6.............            22+2  A9EA..............................          33,000
Dornier Luftfahrt GmbH:
    --Dornier 228-100 and -200..............            19+2  A16EU.............................          42,800
    --Dornier 228-101 and -201..............            19+2  A16EU.............................          32,800
    --Dornier 228-202.......................            19+2  A16EU.............................          29,600
    --Dornier 228-212 (Except SN 155 & 191              19+2  A16EU.............................          26,400
     and up).
    --Dornier 228-212 (SN 155 and 191 and               19+2  A16EU.............................          42,800
     up).
Empresa Brasileira de Aeronautica (Embraer):            19+2  A21SO.............................          30,000
 Embraer EMB-110.
Fairchild Aircraft Corporation:
    --SA226-TC..............................            20+2  A8SW..............................          35,000
    --SA227-AT..............................            14+2  A5SW..............................          35,000
    --SA227-TT..............................             9+2  A5SW..............................          35,000
    --SA227-AC..............................            20+2  A8SW..............................          35,000
    --SA227-PC..............................            20+2  A8SW..............................          35,000
    --SA227-BC..............................            20+2  A8SW..............................          35,000
    --SA227-CC..............................            19+2  A18SW.............................          35,000
    --SA227-DC..............................            19+2  A18SW.............................          35,000
Pilatus Britten-Norman: PBN BN-2 Mk III (all            16+2  A29EU.............................          20,480
 models).
Short Brothers PLC:
    --SD3-30................................            39+2  A41EU.............................          57,600
    --SD3-60................................            39+2  A41EU.............................          28,800
    --SD3-Sherpa............................            39+2  A41EU.............................          40,000
----------------------------------------------------------------------------------------------------------------

PART 129--OPERATIONS: FOREIGN AIR CARRIERS AND FOREIGN OPERATORS OF 
U.S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE

    7. The authority citation for part 129 continues to read as 
follows:

    Authority: 49 U.S.C. 106(g), 40104-40105, 40113, 40119, 44701-
44702, 44712, 44716-44717, 44722, 44901-44904, 44906.
    8. Revise Sec.  129.1 to read as follows:


Sec.  129.1  Applicability and definitions.

    (a) Foreign air carrier operations in the United States. This part 
prescribes rules governing the operation within the United States of 
each foreign air carrier holding the following:
    (1) A permit issued by the Civil Aeronautics Board or the U.S. 
Department of Transportation under 49 U.S.C. 41301 through 41306 
(formerly section 402 of the Federal Aviation Act of 1958, as amended), 
or
    (2) Other appropriate economic or exemption authority issued by the 
Civil Aeronautics Board or the U.S. Department of Transportation.
    (b) Operations of U.S.-registered aircraft solely outside the 
United States. In addition to the operations specified under paragraph 
(a) of this section, Sec. Sec.  129.14, 129.16, 129.20, 129.32, and 
129.33 also apply to U.S.-registered aircraft operated solely outside 
the United States in common carriage by a foreign person or foreign air 
carrier.
    (c) Definitions. For the purpose of this part--
    (1) Foreign person means any person who is not a citizen of the 
United States and who operates a U.S.-registered aircraft in common 
carriage solely outside the United States.
    (2) Years in service means the calendar time elapsed since an 
aircraft was issued its first U.S. or first foreign airworthiness 
certificate.

    9. Add Sec.  129.16 to read as follows:


Sec.  129.16  Supplemental inspections for U.S.-registered aircraft.

    (a) Multiengine airplanes with 10 or more passenger seats. After 
December 5, 2007, a foreign air carrier or foreign person may not 
operate a U.S.-registered multiengine airplane initially type 
certificated with 10 or more passenger seats under this part unless the 
maintenance program for that airplane includes damage-tolerance-based 
inspections and procedures. Paragraphs (c), (d), and (e) of this 
section list the exceptions to this requirement.
    (b) Multiengine airplanes with nine or fewer passenger seats. After 
December 20, 2010, a foreign air carrier or foreign person may not 
operate a U.S.-registered multiengine airplane initially type 
certificated with nine or fewer passenger seats under this part unless 
the inspection program for that airplane includes service-history-based 
inspections and procedures. Paragraphs (d) and (e) of this section list 
the exceptions to this requirement.
    (c) New model added through type certificate amendment. This 
paragraph applies to each U.S.-registered multiengine airplane 
initially type certificated with 10 or more passenger seats that is 
added to a type certificate

[[Page 72763]]

after December 8, 2003, that has a certification basis that does not 
include a requirement for damage-tolerance-based inspections and 
procedures. A foreign air carrier or foreign person may not operate 
that airplane more than 4 years after the date of the type certificate 
amendment unless the maintenance program for that airplane includes 
damage-tolerance-based inspections and procedures.
    (d) Design-life goal airplanes. If on or after December 5, 2007, 
the time in service of the airplane reaches the design-life goal listed 
in appendix B to this part, the foreign air carrier or foreign person 
may operate the airplane until the airplane's time in service reaches 
the design-life goal or until December 20, 2010, whichever occurs 
sooner. After that date, the foreign air carrier or foreign person may 
not operate the airplane unless it complies with paragraph (a) or 
paragraph (b) of this section.
    (e) Airworthiness directive-mandated service-history-based 
inspections. Until December 20, 2010, a foreign air carrier or foreign 
person may operate a U.S.-registered multiengine airplane initially 
type certificated with 10 or more passenger seats and for which an 
airworthiness directive requires the maintenance program to include 
service-history-based inspections and procedures. After that date, the 
foreign air carrier or foreign person may not operate the airplane 
unless the maintenance program for that airplane includes damage-
tolerance-based inspections and procedures.
    (f) Approvals. The inspections and procedures required by this 
section to be included in the certificate holder's maintenance program 
for an airplane must be approved by the FAA Aircraft Certification 
Office or office of the Small Aircraft Directorate or Transport 
Airplane Directorate having cognizance over the type certificate for 
the affected airplane.

    10. Add Sec.  129.33 to read as follows:


Sec.  129.33  Aging airplane inspections and records reviews for U.S.-
registered multiengine aircraft.

    (a) Operation after inspection and records review. After the dates 
specified in this paragraph, a foreign air carrier or foreign person 
may not operate a U.S.-registered multiengine airplane under this part 
unless the Administrator has notified the foreign air carrier or 
foreign person that the Administrator has completed the aging airplane 
inspection and records review required by this section. During the 
inspection and records review, the foreign air carrier or foreign 
person must demonstrate to the Administrator that the maintenance of 
age sensitive parts and components of the airplane has been adequate 
and timely enough to ensure the highest degree of safety.
    (1) Airplanes exceeding 24 years in service on December 8, 2003; 
initial and repetitive inspections and records reviews. For an airplane 
that has exceeded 24 years in service on December 8, 2003, no later 
than December 5, 2007, and thereafter at intervals not to exceed 7 
years.
    (2) Airplanes exceeding 14 years in service but not 24 years in 
service on December 8, 2003; initial and repetitive inspections and 
records reviews. For an airplane that has exceeded 14 years in service, 
but not 24 years in service, on December 8, 2003, no later than 
December 4, 2008, and thereafter at intervals not to exceed 7 years.
    (3) Airplanes not exceeding 14 years in service on December 8, 
2003; initial and repetitive inspections and records reviews. For an 
airplane that has not exceeded 14 years in service on December 8, 2003, 
no later than 5 years after the start of the airplane's 15th year in 
service and thereafter at intervals not to exceed 7 years.
    (b) Unforeseen schedule conflict. In the event of an unforeseen 
scheduling conflict for a specific airplane, the Administrator may 
approve an extension of up to 90 days beyond an interval specified in 
paragraph (b) of this section.
    (c) Airplane and records availability. The foreign air carrier or 
foreign person must make available to the Administrator each U.S.-
registered multiengine airplane for which an inspection and records 
review is required under this section, in a condition for inspection 
specified by the Administrator, together with the records containing 
the following information:
    (1) Total years in service of the airplane;
    (2) Total flight hours of the airframe;
    (3) Total flight cycles of the airframe;
    (4) Date of the last inspection and records review required by this 
section;
    (5) Current status of life-limited parts of the airframe;
    (6) Time since the last overhaul of all structural components 
required to be overhauled on a specific time basis;
    (7) Current inspection status of the airplane, including the time 
since the last inspection required by the inspection program under 
which the airplane is maintained;
    (8) Current status of the following, including the method of 
compliance:
    (i) Airworthiness directives;
    (ii) Corrosion Prevention and Control Programs; and
    (iii) Inspections and procedures required by Sec.  129.16 of this 
part;
    (9) A list of major structural alterations; and
    (10) A report of major structural repairs and the current 
inspection status for those repairs.
    (d) Notification to Administrator. Each foreign air carrier or 
foreign person must notify the Administrator at least 60 days before 
the date on which the airplane and airplane records will be made 
available for the inspection and records review.

    11. Add appendix B to part 129 to read as follows:

                                   Appendix B to Part 129.--Design-Life Goals
----------------------------------------------------------------------------------------------------------------
                                                 Number of                                          Design-life
                Airplane type                      seats          Type certificate data sheet      goal (hours)
----------------------------------------------------------------------------------------------------------------
Raytheon (Beech) Aircraft Co.:
    --Beech 99 (all models).................            19+2  A14CE.............................          46,000
    --Beech 1900 and 1900C..................            13+2  A24CE.............................          45,000
    --Beech 300 and 300LW...................            15+2  A24CE.............................          30,000
    --Beech B300 and B300C..................            19+2  A24CE.............................          30,000
    --Beech 1900D...........................            15+2  A24CE.............................          45,000
British Aerospace Ltd.:
    --BAe Jetstream 3101....................            19+2  A21EU.............................          45,000
    --BAe Jetstream 3201....................            19+2  A56EU.............................          30,000
Cessna Aircraft Co.:
    --Cessna 402 Series (all models except               8+2  A7CE..............................          12,000
     402C).
    --Cessna 402C...........................             8+2  A7CE..............................           7,700

[[Page 72764]]

 
deHavilland Aircraft Co.: DHC-6.............            22+2  A9EA..............................          33,000
Dornier-Luftfahrt GmbH:
    --Dornier 228-100 and -200..............            19+2  A16EU.............................          42,800
    --Dornier 228-101 and -201..............            19+2  A16EU.............................          32,800
    --Dornier 228-202.......................            19+2  A16EU.............................          29,600
    --Dornier 228-212 (Except SN 155 & 191              19+2  A16EU.............................          26,400
     and up).
    --Dornier 228-212 (SN 155 and 191 and               19+2  A16EU.............................          42,800
     up).
Empresa Brasileira de Aeronautica (Embraer):            19+2  A21SO.............................          30,000
 Embraer EMB-110
Fairchild Aircraft Corporation:
    --SA226-TC..............................            20+2  A8SW..............................          35,000
    --SA227-AT..............................            14+2  A5SW..............................          35,000
    --SA227-TT..............................             9+2  A5SW..............................          35,000
    --SA227-AC..............................            20+2  A8SW..............................          35,000
    --SA227-PC..............................            20+2  A8SW..............................          35,000
    --SA227-BC..............................            20+2  A8SW..............................          35,000
    --SA227-CC..............................            19+2  A18SW.............................          35,000
    --SA227-DC..............................            19+2  A18SW.............................          35,000
Pilatus Britten-Norman: PBN BN-2 Mk III (all            16+2  A29EU.............................          20,480
 models).
Piper Aircraft Inc., The New:
    --PA 31 Navajo..........................             6+2  A20SO.............................          11,000
    --PA 31-300 Navajo......................             6+2  A20SO.............................          15,500
    --PA 31P Pressurized Navajo.............             6+2  A8EA..............................          14,000
    --PA 31T Cheyenne and Cheyenne II.......             7+2  A8EA..............................          12,000
    --PA 31-350 Chieftain and (T-1020)......             9+2  A20SO.............................          13,000
    --PA 31-325 Navajo CR...................             9+2  A20SO.............................          11,000
    --PA 31T2 Cheyenne II XL................             5+2  A8EA..............................          11,400
    --PA 31T3 (T-1040) without tip tanks....             9+2  A8EA..............................          17,400
    --PA 31T3 (T-1040) with tip tanks.......             9+2  A8EA..............................          13,800
Short Brothers PLC:
    --SD3-30................................            39+2  A41EU.............................          57,600
    --SD3-60................................            39+2  A41EU.............................          28,800
    --SD3-Sherpa............................            39+2  A41EU.............................          40,000
----------------------------------------------------------------------------------------------------------------

PART 135--OPERATING REQUIREMENTS: COMMUTER AND ON-DEMAND OPERATIONS 
AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT

    12. The authority citation for part 135 continues to read as 
follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44705, 44709, 
44711-44713, 44715-44717, 44722.


    13. Add Sec.  135.168 to read as follows:


Sec.  135.168  Supplemental inspections.

    (a) Applicability. This section applies to each multiengine 
airplane operated by a certificate holder in scheduled operations under 
this part, except for those operations conducted between any point 
within the State of Alaska and any other point within the State of 
Alaska.
    (b) Multiengine airplanes with 10 or more passenger seats. After 
December 5, 2007, a certificate holder may not operate, in scheduled 
operations under this part, a multiengine airplane initially type 
certificated with 10 or more passenger seats unless the maintenance 
program for that airplane includes damage-tolerance-based inspections 
and procedures. Paragraphs (d), (e), and (f) of this section list the 
exceptions to this requirement.
    (c) Multiengine airplanes with nine or fewer passenger seats. After 
December 20, 2010, a certificate holder may not operate, in scheduled 
operations under this part, a multiengine airplane initially type 
certificated with nine or fewer passenger seats unless the inspection 
program for that airplane includes service-history-based inspections 
and procedures. Paragraph (e) of this section lists the exception to 
this requirement.
    (d) New model added through type certificate amendment. This 
paragraph applies to each U.S.-registered multiengine airplane 
initially type certificated with 10 or more passenger seats added to a 
type certificate after December 8, 2003, that has a certification basis 
that does not include a requirement for damage-tolerance-based 
inspections and procedures. A certificate holder may not operate that 
airplane, in scheduled operations, more than 4 years after the date of 
the type certificate amendment unless the maintenance program for that 
airplane includes damage-tolerance-based inspections and procedures.
    (e) Design-life goal airplanes. If on or after December 5, 2007, 
the time in service of the airplane reaches the design-life goal listed 
in appendix G to this part the certificate holder may operate that 
airplane in scheduled operations until the date the airplane's time in 
service reaches the design-life goal or until December 20, 2010, 
whichever occurs sooner. After that date, the certificate holder may 
not operate the airplane in scheduled operations unless it complies 
with paragraph (b) or paragraph (c) of this section.
    (f) Airworthiness directive-mandated service-history-based 
inspections. Until December 20, 2010, a certificate holder may operate 
an airplane for which an airworthiness directive requires the 
maintenance program to include service-history-based inspections and 
procedures. After that date, the certificate holder may not operate the 
airplane unless the maintenance program for that airplane includes 
damage-tolerance-based inspections and procedures.
    (g) Approvals. The inspections and procedures required by this 
section to be included in the certificate holder's maintenance program 
for an airplane

[[Page 72765]]

must be approved by the FAA Aircraft Certification Office or office of 
the Small Aircraft Directorate or Transport Airplane Directorate having 
cognizance over the type certificate for the affected airplane.

    14. Add Sec.  135.422 to read as follows:


Sec.  135.422  Aging airplane inspections and records reviews for 
multiengine airplanes certificated with 10 or more passenger seats.

    (a) Applicability. This section applies to multiengine airplanes 
with 10 or more passenger seats operated by a certificate holder in 
scheduled operations under this part, except for those airplanes 
operated by a certificate holder between any point within the State of 
Alaska and any other point within the State of Alaska.
    (b) Operation after inspections and records review. After the dates 
specified in this paragraph, a certificate holder may not operate a 
multiengine airplane in scheduled operations under this part unless the 
Administrator has notified the certificate holder that the 
Administrator has completed the aging airplane inspection and records 
review required by this section. During the inspection and records 
review, the certificate holder must demonstrate to the Administrator 
that the maintenance of age-sensitive parts and components of the 
airplane has been adequate and timely enough to ensure the highest 
degree of safety.
    (1) Airplanes exceeding 24 years in service on December 8, 2003; 
initial and repetitive inspections and records reviews. For an airplane 
that has exceeded 24 years in service on December 8, 2003, no later 
than December 5, 2007, and thereafter at intervals not to exceed 7 
years.
    (2) Airplanes exceeding 14 years in service but not 24 years in 
service on December 8, 2003; initial and repetitive inspections and 
records reviews. For an airplane that has exceeded 14 years in service, 
but not 24 years in service, on December 8, 2003, no later than 
December 4, 2008, and thereafter at intervals not to exceed 7 years.
    (3) Airplanes not exceeding 14 years in service on December 8, 
2003; initial and repetitive inspections and records reviews. For an 
airplane that has not exceeded 14 years in service on December 8, 2003, 
no later than 5 years after the start of the airplane's 15th year in 
service and thereafter at intervals not to exceed 7 years.
    (c) Unforeseen schedule conflict. In the event of an unforeseen 
scheduling conflict for a specific airplane, the Administrator may 
approve an extension of up to 90 days beyond an interval specified in 
paragraph (c) of this section.
    (d) Airplane and records availability. The certificate holder must 
make available to the Administrator each airplane for which a 
inspection and records review is required under this section, in a 
condition for inspection specified by the Administrator, together with 
the records containing the following information:
    (1) Total years in service of the airplane;
    (2) Total flight hours of the airframe;
    (3) Total flight cycles of the airframe;
    (4) Date of the last inspection and records review required by this 
section;
    (5) Current status of life-limited parts of the airframe;
    (6) Time since the last overhaul of all structural components 
required to be overhauled on a specific time basis;
    (7) Current inspection status of the airplane, including the time 
since the last inspection required by the inspection program under 
which the airplane is maintained;
    (8) Current status of the following, including the method of 
compliance:
    (i) Airworthiness directives;
    (ii) Corrosion Prevention and Control Programs; and
    (iii) Inspections and procedures required by Sec.  135.168 of this 
part;
    (9) A list of major structural alterations; and
    (10) A report of major structural repairs and the current 
inspection status for those repairs.
    (e) Notification to Administrator. Each certificate holder must 
notify the Administrator at least 60 days before the date on which the 
airplane and airplane records will be made available for the inspection 
and records review.

    15. Redesignate existing Sec.  135.423 as Sec.  135.424.
    16. Add new Sec.  135.423 to read as follows:


Sec.  135.423  Aging airplane inspections and records reviews for 
multiengine airplanes certificated with nine or fewer passenger seats.

    (a) Applicability. This section applies to multiengine airplanes 
certificated with nine or fewer passenger seats operated by a 
certificate holder in scheduled operations under this part, except for 
those airplanes operated by a certificate holder between any point 
within the State of Alaska and any other point within the State of 
Alaska.
    (b) Operation after inspections and records review. After the dates 
specified in this paragraph, a certificate holder may not operate a 
multiengine airplane in scheduled operations under this part unless the 
Administrator has notified the certificate holder that the 
Administrator has completed the aging airplane inspection and records 
review required by this section. During the inspection and records 
review, the certificate holder must demonstrate to the Administrator 
that the maintenance of age-sensitive parts and components of the 
airplane has been adequate and timely enough to ensure the highest 
degree of safety.
    (1) Airplanes exceeding 24 years of service in service on December 
8, 2003; initial and repetitive inspections and records reviews. For an 
airplane that has exceeded 24 years in service on December 8, 2003, no 
later than December 5, 2007, and thereafter at intervals not to exceed 
7 years.
    (2) Airplanes not exceeding 14 years in service but not 24 years in 
service on December 8, 2003; initial and repetitive inspections and 
records reviews. For an airplane that has exceeded 14 years in service, 
but not 24 years in service, on December 8, 2003, no later than 
December 4, 2008, and thereafter at intervals not to exceed 7 years.
    (3) Airplanes not exceeding 14 years in service on December 8, 
2003; initial and repetitive inspections and records reviews. For an 
airplane that has not exceeded 14 years in service on December 8, 2003, 
no later than 5 years after the start of the airplane's 15th year in 
service and thereafter at intervals not to exceed 7 years.
    (c) Unforeseen schedule conflict. In the event of an unforeseen 
scheduling conflict for a specific airplane, the Administrator may 
approve an extension of up to 90 days beyond an interval specified in 
paragraph (c) of this section.
    (d) Airplane and records availability. The certificate holder must 
make available to the Administrator each airplane for which an 
inspection and records review is required under this section, in a 
condition for inspection specified by the Administrator, together with 
the records containing the following information:
    (1) Total years in service of the airplane;
    (2) Total flight hours of the airframe;
    (3) Date of the last inspection and records review required by this 
section;
    (4) Current status of life-limited parts of the airframe;
    (5) Time since the last overhaul of all structural components 
required to be overhauled on a specific time basis;
    (6) Current inspection status of the airplane, including the time 
since the last inspection required by the inspection program under 
which the airplane is maintained;

[[Page 72766]]

    (7) Current status of the following, including the method of 
compliance:
    (i) Airworthiness directives;
    (ii) Corrosion Prevention and Control Programs; and
    (iii) Inspections and procedures required by Sec.  135.168 of this 
part;
    (8) A list of major structural alterations; and
    (9) A report of major structural repairs and the current inspection 
status for these repairs.
    (e) Notification to Administrator. Each certificate holder must 
notify the Administrator at least 60 days before the date on which the 
airplane and airplane records will be made available for the inspection 
and records review.

    17. Add appendix G to part 135 to read as follows:

                                   Appendix G to Part 135.--Design-Life Goals
----------------------------------------------------------------------------------------------------------------
                                                 Number of                                          Design-life
                Airplane type                      seats          Type certificate data sheet      goal (hours)
----------------------------------------------------------------------------------------------------------------
Raytheon (Beech) Aircraft Co.:
    --Beech 99 (all models).................            15+2  A14CE.............................          46,000
    --Beech 1900 and 1900C..................            19+2  A24CE.............................          45,000
    --Beech 300 and 300LW...................            13+2  A24CE.............................          30,000
    --Beech B300 and B300C..................            15+2  A24CE.............................          30,000
    --Beech 1900D...........................            19+2  A24CE.............................          45,000
British Aerospace Ltd.:
    --BAe Jetstream 3101....................            19+2  A21EU.............................          45,000
    --BAe Jetstream 3201....................            19+2  A56EU.............................          30,000
Cessna Aircraft Co.:
    --Cessna 402 Series (all models except               8+2  A7CE..............................          12,000
     402C).
    --Cessna 402C...........................             8+2  A7CE..............................           7,700
deHavilland Aircraft Co.:...................
    --DHC-6.................................            22+2  A9EA..............................          33,000
Dornier-Luftfahrt GmbH:
    --Dornier 228-100 and -200..............            19+2  A16EU.............................          42,800
    --Dornier 228-101 and -201..............            19+2  A16EU.............................          32,800
    --Dornier 228-202.......................            19+2  A16EU.............................          29,600
    --Dornier 228-212 (Except SN 155 & 191              19+2  A16EU.............................          26,400
     and up).
    --Dornier 228-212 (SN 155 and 191 and               19+2  A16EU.............................          42,800
     up).
Empresa Brasileira de Aeronautica (Embraer):            19+2  A21SO.............................          30,000
 Embraer EMB-110.
Fairchild Aircraft Corporation:
    --SA226-TC..............................            20+2  A8SW..............................          35,000
    --SA227-AT..............................            14+2  A5SW..............................          35,000
    --SA227-TT..............................             9+2  A5SW..............................          35,000
    --SA227-AC..............................            20+2  A8SW..............................          35,000
    --SA227-PC..............................            20+2  A8SW..............................          35,000
    --SA227-BC..............................            20+2  A8SW..............................          35,000
    --SA227-CC..............................            19+2  A18SW.............................          35,000
    --SA227-DC..............................            19+2  A18SW.............................          35,000
Pilatus Britten-Norman: PBN BN-2 Mk III (all            16+2  A29EU.............................          20,480
 models).
Piper Aircraft Inc., The New:
    --PA 31 Navajo..........................             6+2  A20SO.............................          11,000
    --PA 31-300 Navajo......................             6+2  A20SO.............................          15,500
    --PA 31P Pressurized Navajo.............             6+2  A8EA..............................          14,000
    --PA 31T Cheyenne and Cheyenne II.......             7+2  A8EA..............................          12,000
    --PA 31-350 Chieftain and (T-1020)......             9+2  A20SO.............................          13,000
    --PA 31-325 Navajo CR...................             9+2  A20SO.............................          11,000
    --PA 31T2 Cheyenne II XL................             5+2  A8EA..............................          11,400
    --PA 31T3 (T-1040) without tip tanks....             9+2  A8EA..............................          17,400
    --PA 31T3 (T-1040) with tip tanks.......             9+2  A8EA..............................          13,800
Short Brothers PLC:.........................
    --SD3-30................................            39+2  A41EU.............................          57,600
    --SD3-60................................            39+2  A41EU.............................          28,800
    --SD3-Sherpa............................            39+2  A41EU.............................          40,000
----------------------------------------------------------------------------------------------------------------

PART 183-REPRESENTATIVES OF THE ADMINISTRATOR

    18. The authority citation for part 183 continues to read as 
follows:

    Authority: 31 U.S.C. 9701; 49 U.S.C. 106(g), 40113, 44702, 
45303.


    19. Amend Sec.  183.33 by revising paragraph (a) to read as 
follows:


Sec.  183.33  Designated Airworthiness Representative.

* * * * *
    (a) Perform examination, inspection, and testing services necessary 
to issue, and to determine the continuing effectiveness of, 
certificates, including issuing certificates, as authorized by the 
Director of Flight Standards Service in the area of maintenance or as 
authorized by the Director of Aircraft Certification Service in the 
areas of manufacturing and engineering.
* * * * *

    Issued in Washington, DC, on November 1, 2002.
Marion C. Blakey,
Administrator.
[FR Doc. 02-30111 Filed 12-5-02; 8:45 am]
BILLING CODE 4910-13-P