[Federal Register Volume 60, Number 29 (Monday, February 13, 1995)]
[Proposed Rules]
[Pages 8206-8209]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3515]



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14 CFR Part 39

[Docket No. 93-NM-219-AD]


Airworthiness Directives; Lockheed Model L-1011-385-1 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Lockheed Model L-1011-385-1 
series airplanes. This proposal would require implementation of a 
Supplemental Inspection Document (SID) program of structural 
inspections to detect fatigue cracking, and repair, if necessary, to 
ensure continued airworthiness of these airplanes as they approach the 
manufacturer's original fatigue design life goal. This proposal is 
prompted by a structural re-evaluation by the manufacturer that 
identified certain structural details where fatigue damage is likely to 
occur. The actions specified by the proposed AD are intended to prevent 
fatigue cracking that could compromise the structural integrity of 
these airplanes.
DATES: Comments must be received by April 10, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 93-NM-219-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Lockheed Aeronautical Systems Support Company, Field 
Support Department, Dept. 693, Zone 0755, 2251 Lake Park Drive, Smyrna, 
Georgia 30080. This information may be examined at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at 
the FAA, Small Airplane Directorate, Atlanta Aircraft Certification 
Office, Campus Building, 1701 Columbia Avenue, Suite 2-160, College 
Park, Georgia.
FOR FURTHER INFORMATION CONTACT: Thomas Peters, Aerospace Engineer, 
Flight Test Branch, ACE-160A, FAA, Small Airplane Directorate, Atlanta 
Aircraft Certification Office, Campus Building, 1701 Columbia Avenue, 
Suite 2-160, College Park, Georgia 30337-2748; telephone (404) 305-
7367; fax (404) 305-7348.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report [[Page 8207]] summarizing each FAA-public contact 
concerned with the substance of this proposal will be filed in the 
Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 93-NM-219-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 93-NM-219-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    In April 1988, a transport category airplane managed to land after 
tiny cracks in rivet holes in the upper fuselage linked together, 
causing structural failure and explosive decompression. An 18-foot 
section ripped from the fuselage. This accident focused greater 
attention on the problem of aging aircraft.
    In June 1988, the FAA sponsored a conference on aging airplane 
issues, which was attended by representatives of the aviation industry 
from around the world. It became obvious that, because of the 
tremendous increase in air travel, the relatively slow pace of new 
airplane production, and the apparent economic feasibility of operating 
older technology airplanes rather than retiring them, increased 
attention needed to be focused on this aging fleet and maintaining its 
continued operational safety.
    The Air Transport Association (ATA) of America and the Aerospace 
Industries Association (AIA) of America committed to identifying and 
implementing procedures to ensure continued structural airworthiness of 
aging transport category airplanes. An Airworthiness Assurance Working 
Group (AAWG), with representatives from the aircraft operators, 
manufacturers, regulatory authorities, and other aviation 
representatives, was originally established in August 1988. The 
objective of the AAWG was to sponsor ``Task Groups'' to:
    1. Select service bulletins, applicable to each airplane model in 
the transport fleet, to be recommended for mandatory modification of 
aging airplanes,
    2. Develop corrosion directed inspections and prevention programs,
    3. Review the adequacy of each operator's structural maintenance 
program,
    4. Review and update the Supplemental Inspection Documents (SID), 
and
    5. Assess repair quality.
    The Task Group assigned to review Lockheed Model L-1011-385 series 
airplanes completed its work on Item 1 (mandatory structural 
modifications), above, in June 1990. The Task Group's recommendations 
are contained in Revision 1 of Lockheed Service Bulletin 093-51-035, 
``Structures--Aging Aircraft Structural Modifications and Inspections--
Collector Service Bulletin,'' dated December 16, 1991. The FAA issued 
AD 94-05-01, amendment 39-8839 (59 FR 10275, March 4, 1994), which 
mandates the installation of the modifications specified in that 
document.
    The Task Group completed its work on Item 2 (corrosion-directed 
inspections) and developed a baseline program for controlling corrosion 
problems that may jeopardize the continued airworthiness of the 
Lockheed Model L-1011 fleet. This program is contained in Lockheed 
Document Number LR 31889, ``Corrosion Prevention and Control Program, 
TriStar L-1011,'' dated March 15, 1991. The FAA issued AD 93-20-03, 
amendment 39-8710 (58 FR 60775, November 18, 1993), which requires the 
implementation of a corrosion prevention and control program.
    The Task Group completed its work on Item 4 (Supplemental 
Inspection Document) in May 1993 and developed a program for the 
implementation of a SID program identified in Lockheed Document Number 
LG92ER0060, ``L-1011-385 Series Supplemental Inspection Document,'' 
revised January 1994, which recommends structural inspections of older 
airplanes. The Task Group has identified certain service difficulties 
that warrant mandatory inspections following mandatory modification of 
these airplanes. The Task Group considers that these service 
difficulties can be controlled safely by repetitively inspecting 
following modification of these airplanes, and that, because of the 
safety implications, the inspections should be mandatory to assure that 
all operators perform them. Typically, the addressed unsafe conditions 
(i.e., fatigue cracking) have occurred infrequently on older airplanes, 
and the Task Group has a very high degree of confidence in the ability 
of an inspection program to detect the damage before it impairs safety.

Explanation of Service Information

    Lockheed Document Number LG92ER0060, ``L-1011-385 Series 
Supplemental Inspection Document,'' revised January 1994 (hereafter 
referred to as ``the Lockheed Document''), is the result of a 
structural re-evaluation conducted by Lockheed. The criteria that were 
used for this re-evaluation are contained in FAA Advisory Circular (AC) 
91-56, ``Supplemental Structural Inspection Program for Large Transport 
Category Airplanes,'' and Federal Aviation Regulation 25.571 (14 CFR 
25.571), amendment 25-45. During this structural re-evaluation, 
Lockheed examined Structurally Significant Details (SSD), which are 
structural parts and components that carry significant ground, flight, 
cabin pressure, or control loads whose failure could affect the safety 
of the aiplane. From these SSD's, Lockheed identified candidate 
locations for supplemental inspections that have been incorporated into 
the Lockheed Document.
    The Model L-1011-385-3 series airplanes were excluded from this re-
evaluation. These newer, long-range airplanes fly less frequently and 
are neither imminently approaching nor have they exceeded the 
manufacturer's original fatigue design life goal. (However, as these 
airplanes accumulate more hours time-in-service, and as the critical 
area selection is developed and identified, the FAA anticipates that 
these airplanes will be addressed in future rulemaking actions.)
    Specifically, the Lockheed Document describes procedures for 
supplemental inspections of SSD's for Model L-1011-385-1 series 
airplanes. This Lockheed Document identifies SSD's in 13 fuselage, one 
stabilizer, and 14 wing critical areas. The Document also specifies 
that operators submit the results of these inspections to Lockheed.
    The Task Group has reviewed the Lockheed Document, and has 
recommended it to the FAA for mandatory inspection following mandatory 
modification to ensure the successful long-term operation of Lockheed 
Model L-1011-385 series airplanes. The FAA has concurred with the Task 
Group's recommendations and has determined that AD action is warranted 
to mandate the inspections and modifications to ensure the continued 
airworthiness of the Model L-1011-385 fleet. Fatigue cracking in the 
SSD's specified in the Lockheed Document, if not detected and corrected 
in a timely manner, could compromise the structural integrity of the 
airplane. [[Page 8208]] 

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require a revision to the FAA-approved maintenance 
inspection program to include a SID program of structural inspections. 
The intent of these inspections is to detect fatigue cracking in order 
to ensure continued airworthiness as these airplanes approach the 
manufacturer's original fatigue design life goal.
    Specifically, this proposal would require that the initial 
inspection for each individual SSD be performed within one ``repeat 
interval'' after the effective date of the AD or prior to the threshold 
specified in the Lockheed Document, whichever occurs later. This 
proposal would provide operators with time for planning and scheduling 
by granting a deviation of 10 percent for the interval specified in the 
Lockheed Document for subsequent repetitive inspections. This action 
also would require that the results of the inspections be reported to 
Lockheed. These actions would be required to be accomplished in 
accordance with the Lockheed Document described previously.
    This proposal also would require that any cracking detected be 
repaired either in accordance with the appropriate information 
referenced in the Lockheed Document, in accordance with the Structural 
Repair Manual, or in accordance with a method approved by the FAA.

Economic Impact Information

    There are approximately 186 Lockheed Model L-1011-385-1 series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 100 airplanes of U.S. registry would be affected by this 
proposed AD. Incorporation of the SID into an operator's maintenance 
program would take approximately 550 work hours, and the average labor 
rate is $60 per work hour. Based on these figures, the total cost 
impact of the proposed AD to incorporate the SID into an operator's 
maintenance program is estimated to be $33,000 per operator.
    Initially, the FAA estimates that it would take 293 work hours to 
accomplish the 28 inspections specified in the SSID, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
total cost impact of the proposed AD for the first year is estimated to 
be $1,758,000, or $17,580 per airplane.
    However, the FAA has been advised that the terminating modification 
for SSD 53-2-1, which is described in the Lockheed Document, has been 
accomplished by the entire L-1011-385-1 fleet. Therefore, the 
inspections for SSD 53-2-1, which would have required 48 work hours per 
airplane to accomplish, will not need to be performed. In light of 
this, the cost impact for the initial inspections contained in this 
proposal is now only $1,470,000, or $14,700 per airplane.
    The recurring inspection cost impact on the affected operators is 
estimated to be 52 work hours per airplane at an average labor cost of 
$60 per work hour. Based on these figures, the annual recurring cost of 
this AD is estimated to not exceed $312,000 for the affected U.S. 
fleet, or $3,120 per airplane.
    Based on the above figures, the total cost impact of this AD for 
the first year is estimated to not exceed $47,700 per airplane, and 
$2,820 per airplane for each year thereafter.
    The FAA recognizes that the obligation to maintain aircraft in an 
airworthy condition is vital, but sometimes expensive. Because AD's 
require specific actions to address specific unsafe conditions, they 
appear to impose costs that would not otherwise be borne by operators. 
However, because of the general obligation of operators to maintain 
aircraft in an airworthy condition, this appearance is deceptive. 
Attributing those costs solely to the issuance of this AD is 
unrealistic because, in the interest of maintaining safe aircraft, 
prudent operators would accomplish the required actions even if they 
were not required to do so by the AD.
    A full cost-benefit analysis has not been accomplished for this 
proposed AD. As a matter of law, in order to be airworthy, an aircraft 
must conform to its type design and be in a condition for safe 
operation. The type design is approved only after the FAA makes a 
determination that it complies with all applicable airworthiness 
requirements. In adopting and maintaining those requirements, the FAA 
has already made the determination that they establish a level of 
safety that is cost-beneficial. When the FAA, as in this proposed AD, 
makes a finding of an unsafe condition, this means that the original 
cost-beneficial level of safety is no longer being achieved and that 
the proposed actions are necessary to restore that level of safety. 
Because this level of safety has already been determined to be cost-
beneficial, a full cost-benefit analysis for this proposed AD would be 
redundant and unnecessary.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Lockheed: Docket 93-NM-219-AD.

    Applicability: Model L-1011-385-1, -385-1-14, and -385-1-15 
series airplanes, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracking that could compromise the structural 
integrity of these airplanes, accomplish the following:
    (a) Within 6 months after the effective date of this AD, 
incorporate a revision into the FAA-approved maintenance inspection 
program which provides for inspection(s) of [[Page 8209]] the 
structurally significant details (SSD) defined in Lockheed Document 
Number LG92ER0060, ``L-1011-385 Series Supplemental Inspection 
Document,'' revised January 1994.
    (1) The initial inspection for each SSD must be performed within 
one repeat interval after the effective date of this AD, or prior to 
the threshold specified in the Lockheed Document for that SSD, 
whichever occurs later.
    (2) A 10 percent deviation from the repetitive interval 
specified in the Lockheed Document for that SSD is acceptable to 
allow for planning and scheduling time.
    (3) If the Lockheed Document specifies that inspection of any 
SSD be performed at every ``C'' check, those inspections must be 
performed at intervals not to exceed 5,000 hours time-in-service or 
2,500 flight cycles, whichever occurs earlier.
    (4) If the Lockheed Document specifies either the initial 
inspection or the repetitive inspection intervals for any SSD in 
terms of flight hours or flight cycles, the inspection shall be 
performed prior to the earlier of the terms (whichever occurs first 
on the airplane: either accumulated number of flight hours, or 
accumulated number of flight cycles).
    (5) The non-destructive inspection techniques referenced in 
Appendix VI of the Lockheed Document (Revision A of Lockheed Drawing 
1647194) provide acceptable methods for accomplishing the 
inspections required by this AD.
    (b) If any cracking is found in any SSD, prior to further 
flight, repair in accordance with either paragraph (b)(1), (b)(2), 
or (b)(3) of this AD:
    (1) In accordance with the applicable service bulletin 
referenced in Lockheed Document Number LG92ER0060, ``L-1011-385 
Series Supplemental Inspection Document,'' revised January 1994; or
    (2) In accordance with the Structural Repair Manual; or
    (3) In accordance with a method approved by the Manager, Atlanta 
Aircraft Certification Office (ACO), FAA, Small Airplane 
Directorate.
    (c) Within 30 days after returning the airplane to service, 
subsequent to accomplishment of the inspection(s) specified in 
Lockheed Document Number LG92ER0060, ``L-1011-385 Series 
Supplemental Inspection Document,'' revised January 1994, submit a 
report of the results (positive or negative) of the inspection(s) to 
Lockheed in accordance with Section V., Data Reporting System (DRS), 
of the Lockheed Document. Information collection requirements 
contained in this regulation have been approved by the Office of 
Management and Budget (OMB) under the provisions of the Paperwork 
Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been 
assigned OMB Control Number 2120-0056.
    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Atlanta ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Atlanta ACO.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on February 7, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-3515 Filed 2-10-95; 8:45 am]
BILLING CODE 4910-13-U