[Federal Register Volume 60, Number 35 (Wednesday, February 22, 1995)]
[Proposed Rules]
[Pages 9796-9799]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-4253]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-254-AD]


Airworthiness Directives; Lockheed Model L-1011-385 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 Lockheed Model L-1011-385 series 
airplanes. This proposal would require modifications of various fluid 
drainage areas of the fuselage. This proposal is prompted by incidents 
involving corrosion and fatigue cracking in transport category 
airplanes that are approaching or have exceeded their economic design 
goal; these incidents have jeopardized the airworthiness of the 
affected airplanes. The actions specified by the proposed AD are 
intended to prevent degradation of the structural capabilities of the 
affected airplanes due to problems associated with corrosion.

DATES: Comments must be received by April 17, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-254-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, Atlanta Aircraft Certification Office, Small Airplane 
Directorate, Campus Building, 1701 Columbia Avenue, Suite 2-160, 
College Park, Georgia.

FOR FURTHER INFORMATION CONTACT: Thomas Peters, Flight Test Branch, 
ACE-160A, FAA, Atlanta Aircraft Certification Office, Small Airplane 
Directorate, 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 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 94-NM-254-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. 94-NM-254-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    In April 1988, a high-cycle transport category airplane 
(specifically, a Boeing Model 737) was involved in an accident in which 
the airplane suffered major structural damage during flight. 
[[Page 9797]] Investigation of this accident revealed that the airplane 
had numerous fatigue cracks and a great deal of corrosion. Subsequent 
inspections conducted by the operator on other high-cycle transport 
category airplanes in its fleet revealed that other airplanes had 
extensive fatigue cracking and corrosion.
    Prompted by the data gained from this accident, the FAA sponsored a 
conference on aging airplanes in June 1988, which was attended by 
representatives from the aviation industry and airworthiness 
authorities 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 the aging airplane fleet and 
maintaining its continued operational safety.
    The Air Transport Association (ATA) of America and the Aerospace 
Industries Association (AIA) of America agreed to undertake the task of 
identifying and implementing procedures to ensure the continued 
structural airworthiness of aging transport category airplanes. An 
Airworthiness Assurance Working Group (AAWG) was established initially 
in August 1988, with members representing aircraft manufacturers, 
operators, regulatory authorities, and other aviation industry 
representatives worldwide. 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 L-1011 Structures Task Group, which was assigned by the AAWG to 
review the Lockheed Model L-1011-385 series airplanes, completed its 
work on Item 2 in 1991 and developed a baseline program for controlling 
corrosion problems that may jeopardize the continued airworthiness of 
the Model L-1011 fleet. The program is contained Lockheed Document 
Number LR 31889, ``Corrosion Prevention and Control Program, TriStar L-
1011,'' dated March 15, 1991.
    The FAA reviewed and approved that Document and, on October 8, 
1993, issued AD 93-20-03, amendment 39-8710 (58 FR 60775, November 18, 
1993), which is applicable to all Lockheed Model L-1011 series 
airplanes. That AD requires the implementation of a corrosion 
prevention and control program (CPCP), comparable to the one outlined 
in the Lockheed Document, either by accomplishing specific tasks or by 
revising the FAA-approved maintenance inspection program to include 
such a program.

Current Service Information

    Since issuance of AD 93-20-03, the FAA has reviewed and approved 
Revision A of Lockheed Document Number LR 31889, ``Corrosion Prevention 
and Control Program, TriStar L-1011,'' dated April 1994. This revision 
of the Lockheed Document contains Section 7.2, which lists twelve 
Lockheed service bulletins that have been recommended for mandatory 
action by the L-1011 Structures Task Group.
    The twelve Lockheed service bulletins recommended by the Task Group 
describe various modifications, installations, and inspections of the 
fuselage and wings that are intended to decrease the airplane's 
susceptibility to corrosion in specific areas. The pertinent Lockheed 
service bulletins are:
    1. Service Bulletin 093-51-007, Revision 5, dated December 20, 
1973, describes procedures for modifying the afterbody-emennage-wing 
area to improve drainage capability.
    2. Service Bulletin 093-53-061, Revision 1, dated June 20, 1974, 
describes procedures for modifying the drainage provisions at the 
surround structure of the C-1, C-2, and C-3 cargo doors.
    3. Service Bulletin 093-53-068, dated October 23, 1974, describes 
procedures for installing a drain at the C-1A cargo door sill.
    4. Service Bulletin 093-53-095, Revision 2, dated June 22, 1987, 
describes procedures for installing additional provisions for drainage 
at the pressure deck of the nose landing gear.
    5. Service Bulletin 093-53-113, dated November 12, 1975, describes 
procedures for a modifying the area of the stringers at Fuselage 
Station (FS) 1792 to improve fluid drainage.
    6. Service Bulletin 093-53-157, dated May 3, 1977, describes 
procedures for inspecting and modifying the sealing and drainage 
provisions at the aft pressure bulkhead.
    7. Service Bulletin 093-53-186, Revision 3, dated June 11, 1991, 
describes procedures for the installing additional drainage provisions 
in the fuselage drain system.
    8. Service Bulletin 093-53-192, Revision 2, dated December 9, 1981, 
describes procedures for modifying the fuselage drain system.
    9. Service Bulletin 093-53-204, Revision 1, dated March 26, 1984, 
describes procedures for modifying the door sill drain and cargo 
compartment beam at the galley and door compartments.
    10. Service Bulletin 093-53-234, Revision 2, dated November 12, 
1992, describes procedures for modifying the galley door sill area to 
improve corrosion resistance.
    11. Service Bulletin 093-57-089, Revision 1, dated October 4, 1976, 
describes procedures for installing drain provisions and a dam in the 
main landing gear torque box.
    12. Service Bulletin 093-57-138, Revision 1, dated July 17, 1981, 
and Change Note, dated September 3, 1982, describe procedures for 
inspecting the lower surface bolts at wing body line (WBL) 115.95 to 
detect corrosion, and necessary modification.
    The FAA has considered the recommendation of the Task Group and 
concurs with it. The FAA has determined that accomplishment of the 
actions specified in the twelve Lockheed service bulletins will 
contribute to positively addressing the unsafe condition presented by 
the problems associated with corrosion.

Proposed Requirements of AD

    Since corrosion is likely to exist or develop on airplanes of this 
type design, an AD is proposed which would require the accomplishment 
of the modification, installation, and other actions specified in the 
twelve Lockheed service bulletins described previously.
    Although the proposed AD would be a rulemaking action completely 
separate from AD 93-20-03, the compliance schedule for the 
accomplishment of the proposed actions would be consistent with that 
for the corrosion inspections (tasks) currently required by AD 93-20-
03. The initial corrosion tasks required by AD 93-20-03 must be 
accomplished within various intervals of time, depending on what 
``airplane zone'' is involved; the intervals are measured from a date 
one year after the effective date of that AD. Accordingly, since the 
effective date of AD 93-20-03 is ``December 17, 1993,'' the schedule 
for the actions currently required by that AD is measured from December 
17, 1994.
    This proposed AD would require accomplishment of the proposed 
modifications, installations, and [[Page 9798]] inspections at the same 
time that the initial corrosion task in the corresponding airplane zone 
is required by AD 93-20-03. Scheduling the proposed actions at the same 
time as the currently-required corrosion tasks will minimize additional 
work for affected operators by allowing them to perform all actions 
concurrently. This also will eliminate the necessity of operators 
having to gain access to subject areas more than once.
    Additionally, certain of the modifications described in the twelve 
Lockheed service bulletins were incorporated previously on some 
airplanes during production. For such cases, no additional work would 
be required by this proposed AD.

Economic Impact Information

    There are approximately 241 Model L-1011-385 series airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 117 
airplanes of U.S. registry would be affected by this proposed AD. It 
would take approximately 236 work hours per airplane to accomplish the 
proposed actions, including time to gain access and close up. The 
average labor rate is currently $60 per work hour. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $1,656,720, or $14,160 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted. However, as 
indicated previously, some airplanes that would be subject to the 
proposed AD were modified during production to incorporate certain of 
the proposed modifications and installations. In light of this, the 
total cost impact of this proposal would be considerably less that the 
figure discussed above.
    Additionally, the number of required work hours for the proposed 
requirements of this AD, as indicated above, is presented as if the 
accomplishment of those actions were to be conducted as ``stand alone'' 
actions. However, in actual practice, these actions would be 
accomplished coincidentally or in combination with actions currently 
required by AD 93-20-03. Therefore, the actual number of necessary 
``additional'' work hours will be minimal for the majority of affected 
operators.

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 94-NM-254-AD.

    Applicability: All Model L-1011-385 series airplanes, 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (b) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent structural failure due to the problems associated 
with corrosion accomplish the following:
    (a) Accomplish the modifications, installations, and inspections 
described in the Lockheed service bulletins listed in Section 7.2 of 
Lockheed Document Number LR 31889, ``Corrosion Prevention and 
Control Program, TriStar L-1011,'' Revision A, dated April 1994 
(hereafter referred to as ``the Document''), in accordance with the 
following schedule:

    Note 2: Airplanes on which the modifications, installations, and 
inspections required by this paragraph have been accomplished prior 
to the effective date of this AD or during production are considered 
to be in compliance with this paragraph.
    Note 3: Airplanes on which the modifications, installations, and 
inspections required by this paragraph have been accomplished 
previously in accordance with an earlier version of the applicable 
service bulletin listed in Section 7.2 of the Document, are 
considered to be in compliance with this paragraph.
    Note 4: ``Airplane zones,'' ``implementation ages,'' and 
``repeat intervals,'' as referred to in this paragraph, are 
specified in Section 4.3 of the Document.

    (1) For modifications, installations, and inspections located in 
an airplane zone that has not yet exceeded the ``implementation 
age'' (IA) for that zone as of December 17, 1994 (one year after the 
effective date of AD 93-20-03, amendment 39-8710): Compliance is 
required no later than the IA plus the repeat (R) interval for the 
applicable zone.
    (2) For modifications, installations, and inspections located in 
an airplane zone that has exceeded the IA for that zone as December 
17, 1994: Compliance is required within one R interval for that 
zone, measured from December 17, 1994.
    (3) For airplanes that are 20 years old or older as of December 
17, 1994: Accomplishment of the modifications, installation, and 
inspections is required within one R interval for the applicable 
airplane zone, but not to exceed 6 years, measured from December 17, 
1994, whichever occurs first.
    (b) 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 Aircraft Certification 
Office (ACO), ACE-115A, FAA, Small Airplane Directorate. 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 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

    [[Page 9799]] (c) 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 15, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-4253 Filed 2-21-95; 8:45 am]
BILLING CODE 4910-13-U