[Federal Register Volume 64, Number 193 (Wednesday, October 6, 1999)]
[Proposed Rules]
[Pages 54230-54232]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25934]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-233-AD]
RIN 2120-AA64
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 supersedure of an existing
airworthiness directive (AD), applicable to certain Lockheed Model L-
1011-385 series airplanes, that currently requires repetitive
inspections to detect cracking of the canted pressure bulkhead at
fuselage station (FS) 1212, and repetitive inspections to detect
cracking of the web at the fastener rows of the vertical stiffener-to-
web; and repair or replacement of the web with a new web, if necessary.
This action would require that the initial inspections be accomplished
at a reduced threshold. This proposal is prompted by a report of
fatigue cracking of the canted pressure bulkhead at FS 1212. The
actions specified by the proposed AD are intended to detect and correct
fatigue cracking of the canted pressure bulkhead at FS 1212, which
could result in blowout of a panel between adjacent stiffeners and
consequent cabin depressurization.
DATES: Comments must be received by November 22, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-233-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 Martin Aircraft & Logistics Center, 120 Orion
Street, Greenville, South Carolina 29605. 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, One Crown Center, 1895 Phoenix
Boulevard, suite 450, Atlanta, Georgia.
FOR FURTHER INFORMATION CONTACT: Thomas Peters, Program Manager,
[[Page 54231]]
Program Management and Services Branch, ACE-118A, FAA, Small Airplane
Directorate, Atlanta Aircraft Certification Office, One Crown Center,
1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone
(770) 703-6063; fax (770) 703-6097.
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 99-NM-233-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-114, Attention: Rules
Docket No. 99-NM-233-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On September 26, 1996, the FAA issued AD 96-20-10, amendment 39-
9776 (61 FR 53044, October 10, 1996), applicable to certain Lockheed
Model L-1011-385 series airplanes, to require inspections to detect
cracking of the canted pressure bulkhead at fuselage station (FS) 1212,
and inspections to detect cracking of the web at the fastener rows of
the vertical stiffener-to-web; and repair or replacement of the web
with a new web, if necessary. That action was prompted by a report of
fatigue cracking of the canted pressure bulkhead at FS 1212. The
requirements of that AD are intended to detect and correct fatigue
cracking of the canted pressure bulkhead at FS 1212, which could result
in blowout of a panel between adjacent stiffeners and consequent cabin
depressurization.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the FAA has received an additional
report of fatigue cracking in the subject area on one of these
airplanes. The airplane on which the cracking occurred had accumulated
fewer flight cycles at the time the cracking was detected than the
number of flight cycles specified as the inspection threshold in AD 96-
20-10.
Explanation of Relevant Service Information
The FAA has reviewed and approved Lockheed L-1011 Service Bulletin
093-53-277, Revision 1, dated November 19, 1998, which describes
procedures for repetitive detailed visual inspections to detect
cracking of the entire aft surface of the canted pressure bulkhead at
FS 1212 between left buttock line (LBL) 103 and right buttock line
(RBL) 103, and repetitive optical inspections (i.e., using a borescope
or mirror) to detect cracking of the web at the fastener rows of the
vertical stiffener-to-web; and repair or replacement of the web with a
new web, if necessary. Accomplishment of the actions specified in the
service bulletin is intended to adequately address the identified
unsafe condition.
Explanation of Requirements of Proposed Rule
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 supersede AD 96-20-10 to continue to require
repetitive inspections to detect cracking of the canted pressure
bulkhead at FS 1212, and repetitive inspections to detect cracking of
the web at the fastener rows of the vertical stiffener-to-web; and
repair or replacement of the web with a new web, if necessary. The
proposed AD would require that the initial inspections be accomplished
at a reduced threshold. The actions would be required to be
accomplished in accordance with the service bulletin described
previously.
Explanation of Changes Made to Requirements of AD 96-20-10
The FAA has restated the compliance time in terms of flight cycles,
instead of landings. This is consistent with the compliance times
stated in the service bulletin. In addition, the inspection identified
in AD 96-20-10 as a ``close visual inspection'' is identified in this
proposed AD as a ``detailed visual inspection.'' Furthermore, the FAA
has added a note to the proposed AD to clarify the definition of a
detailed visual inspection.
Cost Impact
There are approximately 235 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 116 airplanes of U.S. registry
would be affected by this proposed AD. The requirements of this
proposed AD would not add any new additional economic burden on
affected operators, other than the costs that are associated with
beginning the inspections at an earlier time than would have been
required by AD 96-20-10 (initial inspection is now required within
18,000 flight cycles, rather than 20,000 flight cycles).
The inspections that are currently required by AD 96-20-10, and
retained in this proposed AD, take approximately 5 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the currently required
actions on U.S. operators is estimated to be $34,800, or $300 per
airplane, per inspection cycle.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the current or proposed
requirements of this AD action, and that no operator would accomplish
those actions in the future if this AD were not adopted.
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
[[Page 54232]]
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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-9776 (61 FR
53044, October 10, 1996), and by adding a new airworthiness directive
(AD), to read as follows:
Lockheed: Docket 99-NM-233-AD. Supersedes AD 96-20-10, Amendment 39-
9776.
Applicability: Model L-1011-385 series airplanes; serial numbers
1013 through 1250 inclusive; 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 request approval for an
alternative method of compliance in accordance with paragraph (c)(1)
of this AD. The request should include an assessment of the effect
of the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To detect and correct fatigue cracking of the canted pressure
bulkhead at fuselage station (FS) 1212, which could result in
blowout of a panel between adjacent stiffeners and consequent cabin
depressurization, accomplish the following:
Repetitive Inspections
(a) Perform a detailed visual inspection to detect cracking of
the entire aft surface of the canted pressure bulkhead at FS 1212
between left buttock line (LBL) 103 and right buttock line (RBL)
103; and perform an optical inspection using a borescope or other
optical device to detect cracking of the web at the fastener rows of
the vertical stiffener-to-web; in accordance with Lockheed L-1011
Service Bulletin 093-53-277, dated July 2, 1996, or Revision 1,
dated November 19, 1998; at the earlier of the times specified in
paragraphs (a)(1) and (a)(2) of this AD. Thereafter, repeat these
inspections at intervals not to exceed 1,000 flight cycles.
(1) Prior to the accumulation of 20,000 total flight cycles, or
within 60 days after October 25, 1996 (the effective date of AD 96-
20-10), whichever occurs later; or
(2) Prior to the accumulation of 18,000 total flight cycles, or
within 60 days after the effective date of this AD, whichever occurs
later.
Note 2: For the purposes of this AD, a detailed visual
inspection is defined as: ``An intensive visual examination of a
specific structural area, system, installation, or assembly to
detect damage, failure, or irregularity. Available lighting is
normally supplemented with a direct source of good lighting at
intensity deemed appropriate by the inspector. Inspection aids such
as mirror, magnifying lenses, etc., may be used. Surface cleaning
and elaborate access procedures may be required.''
Repair
(b) If any cracking is found during any inspection required by
paragraph (a) of this AD, prior to further flight, accomplish either
paragraph (b)(1) or (b)(2) of this AD.
(1) Accomplish either paragraph (b)(1)(i) or (b)(1)(ii) of this
AD, as applicable.
(i) If the cracking is found in an area that is specified in
Lockheed Repair Drawing LCC-7622-385, repair in accordance with
Lockheed L-1011 Service Bulletin 093-53-277, dated July 2, 1996, or
Revision 1, dated November 19, 1998. Accomplishment of a repair
constitutes terminating action for the repetitive inspections
required by paragraph (a) of this AD at the repaired location only.
Or
(ii) If the cracking is found in an area that is not specified
in Lockheed Repair Drawing LCC-7622-385, repair in accordance with a
method approved by the Manager, Atlanta Aircraft Certification
Office (ACO), FAA, Small Airplane Directorate.
(2) Replace the entire web with a new web in accordance with
Lockheed L-1011 Service Bulletin 093-53-277, dated July 2, 1996, or
Revision 1, dated November 19, 1998. Such replacement constitutes
terminating action for the repetitive inspections required by
paragraph (a) of this AD.
Alternative Methods of Compliance
(c)(1) 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.
(c)(2) Alternative methods of compliance, approved previously in
accordance with AD 96-20-10, amendment 39-9776, are approved as
alternative methods of compliance with paragraph (b) of this AD.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
Special Flight Permits
(d) 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 September 29, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-25934 Filed 10-5-99; 8:45 am]
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