[Federal Register Volume 73, Number 86 (Friday, May 2, 2008)]
[Rules and Regulations]
[Pages 24164-24168]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-9316]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-29043; Directorate Identifier 2007-NM-177-AD;
Amendment 39-15494; AD 2008-09-13]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-300, -400, and -500
Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: We are adopting a new airworthiness directive (AD) for all
Boeing Model 737-300, -400, and -500 series airplanes. This AD requires
revising the FAA-approved maintenance inspection program to include
inspections that will give no less than the required damage tolerance
rating for each structural significant item (SSI), doing repetitive
inspections to detect cracks of all SSIs, and repairing cracked
structure. This AD results from a report of incidents involving fatigue
cracking in transport category airplanes that are approaching or have
exceeded their design service objective. We are issuing this AD to
maintain the continued structural integrity of the entire fleet of
Model 737-300, -400, and -500 series airplanes.
DATES: This AD is effective June 6, 2008.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of June 6,
2008.
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (telephone 800-647-5527) is the Document Management
Facility, U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind, Avenue, SW., Renton, Washington 98057-3356; telephone (425)
917-6440; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to include an airworthiness
[[Page 24165]]
directive (AD) that would apply to all Boeing Model 737-300, -400, and
-500 series airplanes. That NPRM was published in the Federal Register
on August 24, 2007 (72 FR 48597). That NPRM proposed to require
revising the FAA-approved maintenance inspection program to include
inspections that will give no less than the required damage tolerance
rating for each structural significant item (SSI), doing repetitive
inspections to detect cracks of all SSIs, and repairing cracked
structure.
Comments
We gave the public the opportunity to participate in developing
this AD. We considered the comments received from the four commenters.
Requests To Allow Alternative Inspections for Previously Repaired/
Altered Structure
Boeing, Southwest Airlines, and United Airlines request that the
NPRM be revised to include a provision for alternative inspections when
a repair area prohibits operators from doing the inspections specified
in paragraph (h) of the NPRM. The commenters request that the initial
alternative inspection be done within 12 months after the repair is
discovered during the initial inspection required by paragraph (h). Two
of the commenters point out that there is a similar provision in
paragraph (e) of AD 98-11-04 R1, amendment 39-10984 (64 FR 987, January
7, 1999). The commenters state that including such a provision will
assist operators.
We agree. We have added a new paragraph (i) to this AD (and
reidentified subsequent paragraphs) that provides alternative
inspections to those in paragraph (h) of this AD.
Request To Allow Compliance With the Repair Assessment Program (RAP)
Southwest and United request that the RAP be considered an
alternative method of compliance (AMOC) for the supplemental structural
inspection document (SSID) inspections of any repaired or modified SSI
specified in paragraph (h) of the NPRM. United States that the FAA
approved the RAP as an AMOC for those areas of the fuselage covered by
repairs for Models 737-100, -200, and -200C series airplanes. Southwest
states that multiple requirements for an individual repaired or
modified area will create confusion, and that eventually the alternate
inspection procedures will either be duplicated or only approved for
one program.
We partially agree. We agree with the commenters that some of the
inspection areas subject to the requirements of this AD also may be
included in the RAP. The owner/operator of an affected airplane or
Boeing, on behalf of the owner/operator, will need to perform an
evaluation of each of these areas of the airplane to determine if the
actions performed in accordance with the RAP meet the requirements of
the SSID inspection program. Our understanding is that Boeing is
looking into this evaluation; however, we have not received any data
supporting a request for an AMOC. Once the evaluation has been
completed, the owner/operator or Boeing may submit the data to
substantiate that those actions performed in accordance with the RAP
would provide an acceptable level of safety, under the provisions of
paragraph (l) of this AD. We have made no change to the AD in this
regard.
Request To Delegate Approval of Structure Affected by Winglet
Modifications
Southwest requests that the NPRM be revised to allow an Authorized
Representative (AR) for the Boeing Commercial Airplanes Delegation
Option Authorization Organization to approve AMOCs for modified or
altered structure such as winglets. Without such a provision, Southwest
states that operators of airplanes on which winglets have been
installed in accordance with a supplemental type certificate (STC) will
need to seek AMOCs directly from the FAA. Southwest believes that such
a provision would reduce the workload for operators and the FAA.
We do not agree. At this time, we cannot authorize Boeing ARs to
approve repair data or AMOCs for non-Boeing type design products such
as STCs for which Boeing does not have access to the design data. We
have made no change to the AD in this regard.
Request To Approve NPRM as a Method of Compliance With Aging Airplane
Safety Final Rule (AASFR)
Southwest and United request that the NPRM be approved as a method
of compliance for the AASFR for the relevant SSIs.
We partially agree. We agree with the commenters that compliance
with this AD would be an acceptable means of compliance with the AASFR
for the baseline structure of Model 737-300, -400, and -500 series
airplanes. The Costs of Compliance section of the NPRM included such a
statement, which is restated in this final rule. In addition, the
Supplemental Inspections section of the AASFR states, ``The FAA will
accept a SSID program for the baseline structure of an airplane
developed by the OEM and approved by the FAA. If a SSID does not
consider repairs, alterations, and modifications (RAMs), as required by
this rule, the FAA would not accept it as a means to comply with this
portion of the rule.'' Therefore, we find that no change to the final
rule is necessary.
Request To Allow Zonal and Surveillance Inspections
British Airways requests that zonal and surveillance inspections be
considered acceptable for the general visual inspection specified in
Boeing Document D6-82669, ``Supplemental Structural Inspection Document
Models 737-300/400/500 Airplanes,'' Original Release, dated May 2007
(hereafter ``the SSID'') (referred to in the NPRM as the appropriate
source of service information for the proposed actions).
We do not agree. Each operator's maintenance inspection program
defines inspection terminology. That maintenance inspection program
might be defined by different revisions of the Maintenance Steering
Group (MSG) procedures or other procedures accepted by the operator's
Certificate Management Office. Because inspection definitions have
changed over time, each operator must confirm that the maintenance
inspections procedures (e.g., surveillance or general visual
inspections) it performs are equivalent to those specified in section
5.0 of the SSID to take damage tolerance rating (DTR) credit for the
SSID program. In addition, while zonal inspection programs include
general visual inspections of an area, including the structure in that
area, the zonal program might not include the same general visual
inspection required by the SSID such as the specific structural detail,
the frequency to do the inspection, and the requirement to do the
inspection in the direction specified. Therefore, we have made no
change to the AD in this regard.
Request To Extend Compliance Time of Reporting Requirement
Southwest and United also request that the compliance time for the
reporting requirement in Section 6.0, ``SSI Discrepancy Reporting,'' of
the SSID be revised from 5 to 30 days. The commenters state that 5 days
is insufficient time for reviewing documentation from various
maintenance bases.
We do not agree. In developing an appropriate compliance time for
this action, we considered the urgency associated with cracks involving
an SSI or related structure in close vicinity to the SSI as well as the
recommendations
[[Page 24166]]
of the manufacturer. In consideration of these items, we have
determined that a 5-day compliance time for reporting discrepant
inspection findings will enable the manufacturer to obtain better
insight into the nature, cause, and extent of the cracking, and
eventually to develop a final action to address the unsafe condition.
However, according to the provisions of paragraph (l) of this AD, we
might approve requests to adjust the compliance time if the request
includes data that prove that the new compliance time would provide an
acceptable level of safety.
Request To Identify Differences Between the AD and the SSID
British Airways requests that all differences between the AD and
the SSID be identified. British Airways states that such differences
were identified in other SSID ADs.
We partially agree. We agree with the commenter to identify
differences between the AD and the SSID and did so in the Differences
Between the Proposed AD and Service Information section of the NPRM.
However, we find that no change to the final rule is necessary, since
that section of the NPRM does not reappear in the final rule.
Request To Clarify a Certain Section of the Preamble of the NPRM
Boeing requests that the Issuance of Advisory Circular (AC) section
in the preamble of the NPRM be clarified. Boeing states that AC No. 91-
56, ``Supplemental Structural Inspection Program for Large Transport
Category Airplanes,'' dated May 6, 2001, applies to airplanes certified
under the fail-safe and fatigue requirements of Civil Air Regulations
(CAR) 4b or part 25 of the Federal Aviation Regulations (14 CFR part
25), not damage tolerance structural requirements as stated in the
Issuance of AC section of the NPRM.
We agree with Boeing that the identified section could be
clarified. However, no change has been made to the final rule since the
identified sections of the NPRM do not reappear in the final rule.
Explanation of Change to Reported Incidents
We have revised the AD to specify that this AD results from a
report of incidents involving fatigue cracking only.
Explanation of Change to Costs of Compliance
The requirements for the baseline structure of Model 737-300, -400,
and -500 series airplanes are currently described in 14 CFR
121.1109(c)(1) and 129.109(b)(1), not in 14 CFR 121.370(a) and 129.16
as indicated in the third paragraph of the Cost of Compliance section
of the NPRM. Therefore, we have revised the Costs of Compliance section
of the AD accordingly.
Explanation of Editorial Changes
We have revised references to the title of Boeing Document D6-82669
from ``Supplemental Structural Inspection Document,'' to ``Supplemental
Structural Inspection Document Models 737-300/400/500 Airplanes'' in
this AD.
Conclusion
We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
the AD with the changes described previously. We also determined that
these changes will not increase the economic burden on any operator or
increase the scope of the AD.
Costs of Compliance
There are about 1,961 airplanes of the affected design in the
worldwide fleet. The following table provides the estimated costs for
U.S. operators to comply with this AD.
Estimated Costs
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Number of U.S.-
Action Work hours Average labor Cost registered Fleet cost
rate per hour airplanes
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Revision of maintenance 1,200 per $80 $96,000 per 599 $2,496,000.
inspection program. operator (26 operator.
U.S.
operators).
Inspections.................. 600 per 80 $48,000, per 599 $28,752,000 per
airplane. airplane, per inspection
inspection cycle.
cycle.
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The number of inspection work hours, as indicated above, is
presented as if the accomplishment of the actions in this AD are to be
conducted as ``stand alone'' actions. However, in actual practice,
these actions for the most part will be done coincidentally or in
combination with normally scheduled airplane inspections and other
maintenance program tasks. Therefore, the actual number of necessary
additional inspection work hours will be minimal in many instances.
Additionally, any costs associated with special airplane scheduling
will be minimal.
Further, compliance with this AD will be a means of compliance with
the AASFR for the baseline structure of Model 737-300, -400, and -500
series airplanes. The AASFR requires certain operators to incorporate
damage tolerance inspections into their maintenance inspection
programs. These requirements are described in 14 CFR 121.1109(c)(1) and
129.109(b)(1). Accomplishment of the actions required by this AD will
meet the requirements of these CFR sections for the baseline structure.
The costs for accomplishing the inspection portion of this AD were
accounted for in the regulatory evaluation of the AASFR final rule.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. ``Subtitle VII: Aviation
Programs,'' describes in more detail the scope of the Agency's
authority.
We are issuing this rulemaking under the authority described in
``Subtitle VII, Part A, Subpart III, Section 44701: General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect on the States,
on the relationship between the national government and the States, or
on the distribution of power and
[[Page 24167]]
responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979), and
(3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new AD:
2008-09-13 Boeing: Amendment 39-15494. Docket No. FAA-2007-29043;
Directorate Identifier 2007-NM-177-AD.
Effective Date
(a) This airworthiness directive (AD) is effective June 6, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to all Boeing Model 737-300, -400, and -500
series airplanes, certificated in any category.
Unsafe Condition
(d) This AD results from a report of incidents involving fatigue
cracking in transport category airplanes that are approaching or
have exceeded their design service objective. We are issuing this AD
to maintain the continued structural integrity of the entire fleet
of Model 737-300, -400, and -500 series airplanes.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Service Information
(f) The term ``the SSID,'' as used in this AD, means Boeing
Document D6-82669, ``Supplemental Structural Inspection Document
Models 737-300/400/500 Airplanes,'' Original Release, dated May
2007.
Revision of the FAA-Approved Maintenance Inspection Program
(g) Before the accumulation of 66,000 total flight cycles, or
within 12 months after the effective date of this AD, whichever
occurs later, incorporate a revision into the FAA-approved
maintenance inspection program that provides no less than the
required damage tolerance rating (DTR) for each structural
significant item (SSI) listed in the SSID. (The required DTR value
for each SSI is listed in the SSID.) The revision to the maintenance
inspection program must include and must be implemented in
accordance with the procedures in Section 5.0, ``Damage Tolerance
Rating (DTR) System Application,'' and Section 6.0, ``SSI
Discrepancy Reporting'' of the SSID. Under the provisions of the
Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.), the Office
of Management and Budget (OMB) has approved the information
collection requirements contained in this AD and has assigned OMB
Control Number 2120-0056.
Initial and Repetitive Inspections
(h) Except as provided by paragraph (i) of this AD: Before the
accumulation of 66,000 total flight cycles, or within 4,000 flight
cycles measured from 12 months after the effective date of this AD,
whichever occurs later, do the applicable initial inspections to
detect cracks of all SSIs, in accordance with the SSID. Repeat the
applicable inspections thereafter at the intervals specified in
Section 3.0, ``Implementation'' of the SSID.
(i) For any SSI that has been repaired or altered before the
effective date of this AD such that the repair or design change
affects your ability to accomplish the actions required by paragraph
(h) of this AD: You must request FAA approval of an alternative
method of compliance (AMOC) in accordance with section 39.17 of the
Federal Aviation Regulations (14 CFR 39.17), at the initial
compliance time specified in paragraph (h) of the AD; or do the
actions specified in paragraphs (i)(1) and (i)(2) of this AD, at the
times specified in those paragraphs, as an approved means of
compliance with the requirements of paragraph (h) of this AD.
(1) At the initial compliance time specified in paragraph (h) of
the AD, identify each repair or design change to that SSI.
(2) Within 12 months after the identification of a repair or
design change required by paragraph (i)(1) of this AD, assess the
damage tolerance characteristics of each SSI affected by each repair
or design change to determine the effectiveness of the applicable
SSID inspection for that SSI and if not effective, incorporate a
revision into the FAA-approved maintenance inspection program to
include a damage-tolerance based alternative inspection program for
each affected SSI. Thereafter, inspect the affected structure in
accordance with the alternative inspection program. The inspection
method and compliance times (i.e., threshold and repeat intervals)
of the alternative inspection program must be approved in accordance
with the procedures specified in paragraph (l) of this AD.
Repair
(j) If any cracked structure is found during any inspection
required by paragraph (h) or (i) of this AD, before further flight,
repair the cracked structure using a method approved in accordance
with the procedures specified in paragraph (l) of this AD.
Inspection Program for Transferred Airplanes
(k) Before any airplane that is subject to this AD and that has
exceeded the applicable compliance times specified in paragraph (h)
of this AD can be added to an air carrier's operations
specifications, a program for the accomplishment of the inspections
required by this AD must be established in accordance with paragraph
(k)(1) or (k)(2) of this AD, as applicable.
(1) For airplanes that have been inspected in accordance with
this AD: The inspection of each SSI must be done by the new operator
in accordance with the previous operator's schedule and inspection
method, or the new operator's schedule and inspection method, at
whichever time would result in the earlier accomplishment for that
SSI inspection. The compliance time for accomplishment of this
inspection must be measured from the last inspection accomplished by
the previous operator. After each inspection has been done once,
each subsequent inspection must be performed in accordance with the
new operator's schedule and inspection method.
(2) For airplanes that have not been inspected in accordance
with this AD: The inspection of each SSI required by this AD must be
done either before adding the airplane to the air carrier's
operations specification, or in accordance with a schedule and an
inspection method approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA. After each inspection has been done
once, each subsequent inspection must be done in accordance with the
new operator's schedule.
Alternative Methods of Compliance (AMOCs)
(l)(1) The Manager, Seattle ACO, has the authority to approve
AMOCs for this AD, if requested in accordance with the procedures
found in 14 CFR 39.19.
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
(3) An AMOC that provides an acceptable level of safety may be
used for any repair required by this AD, if it is approved by an
Authorized Representative for the Boeing Commercial Airplanes
Delegation Option Authorization Organization who has been authorized
by the Manager, Seattle ACO, to make those findings. For a repair
method to
[[Page 24168]]
be approved, the repair approval must specifically refer to this AD.
Material Incorporated by Reference
(m) You must use Boeing Document D6-82669, ``Supplemental
Structural Inspection Document Models 737-300/400/500 Airplanes,''
Original Release, dated May 2007, to do the actions required by this
AD, unless the AD specifies otherwise.
(1) The document contains the following errors:
(i) Pages 8.0.3 and 8.0.4 of Section 8.0, as specified in the
List of Effective Pages, do not exist.
(ii) There are two sets of pages (four pages total) with the
same page numbers in Section 11.3 (i.e., pages E.30.1 and E.30.2).
The first set of page numbers (i.e., DTR Check Form for Item E-30
and the following blank page) is correct. The second set of page
numbers (i.e., DTR Check Form for Item E-31 and the following blank
page) is incorrect. Those pages should be identified as page numbers
31.1 and 31.2, as specified in the List of Effective Pages.
(iii) None of the pages are dated. The issue date for those
pages is May 2007, as specified in the Revision Highlights section.
(2) The Director of the Federal Register approved the
incorporation by reference of this service information under 5
U.S.C. 552(a) and 1 CFR part 51.
(3) For service information identified in this AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington
98124-2207.
(4) You may review copies of the service information
incorporated by reference at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
National Archives and Records Administration (NARA). For information
on the availability of this material at NARA, call 202-741-6030, or
go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Issued in Renton, Washington, on April 8, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-9316 Filed 5-1-08; 8:45 am]
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