[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]
-----------------------------------------------------------------------
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).
-----------------------------------------------------------------------
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
