[Federal Register Volume 60, Number 177 (Wednesday, September 13, 1995)]
[Rules and Regulations]
[Pages 47464-47466]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-22591]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-153-AD; Amendment 39-9366; AD 95-18-52]
Airworthiness Directives; Lockheed Model L-1011-385 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This document publishes in the Federal Register an amendment
adopting Airworthiness Directive (AD) T95-18-52 that was sent
previously to all known U.S. owners and operators of Lockheed Model L-
1011-385 airplanes by individual telegrams. This AD requires visual
inspections to detect cracking of the fittings that attach the aft
pressure bulkhead to the fuselage stringers, replacement of cracked
fittings, and repair of adjacent structure if found to be cracked. This
amendment is prompted by reports of cracks found in these fittings. The
actions specified by this AD are intended to prevent failure of these
fittings due to fatigue cracking; such failure could result in rapid
decompression of the airplane during flight.
DATES: Effective September 28, 1995, to all persons except those
persons to whom it was made immediately effective by telegraphic AD
T95-18-52, issued August 29, 1995, which contained the requirements of
this amendment.
Comments for inclusion in the Rules Docket must be received on or
before November 13, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-153-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
Information concerning this AD 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 B. Peters, Aerospace Engineer,
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: On August 29, 1995, the FAA issued
telegraphic AD T95-18-51, which is applicable to Lockheed Model L-1011-
385 series airplanes.
The FAA recently received a report from an operator of Lockheed
Model L-1011-385 series airplanes indicating that the aft pressure
bulkhead on an airplane failed while it was in flight, which resulted
in rapid decompression of the airplane. This airplane had accumulated
52,010 hours time-in-service and 25,721 total flight cycles.
Investigation revealed that 19 of the fittings that attach the aft
pressure bulkhead to the fuselage stringers at stringers 10 through 55
were severed on this airplane. Additionally, the vertical leg of the
bulkhead outer tee was cracked between these stringers. The cause of
the cracking of the fittings has been attributed to fatigue.
Subsequent inspections of 15 additional airplanes in the fleet
revealed cracking in the fittings of 5 of those airplanes; however,
none of those fittings were severed.
Fatigue cracking, if not detected and corrected in a timely manner,
could lead to failure of the fittings that attach the aft pressure
bulkhead to the fuselage stringers, and subsequently could result in
rapid decompression of the airplane during flight.
Since the unsafe condition described is likely to exist or develop
on other airplanes of the same type design, the FAA issued Telegraphic
AD T95-18-52 to ensure that cracked fittings are identified and
replaced in a timely manner. The AD requires a detailed visual
inspection to detect cracking of the fittings that attach the aft
pressure bulkhead to the fuselage stringers at stringers 1 through 10
(on the right side of the airplane) and at stringers 64 through 56 (on
the left side of the airplane). If cracking is found in any fitting,
the fitting must be replaced and an additional detailed visual
inspection must be performed to detect cracking in the radius at the
lower end of the vertical leg of the bulkhead T-shaped frame. If
cracking is found in the T-shaped frame, the cracked frame must be
repaired.
Additionally, if cracking is detected in the fittings of either
stringer 10 or 56, the fitting(s) in the adjacent outboard stringer(s)
must be inspected until the fittings are found to be free of cracks.
The detailed visual inspections of the fittings and necessary
follow-on actions are to be repeated at specified intervals.
This AD also requires that operators submit, to the FAA, a report
of the findings of their inspections.
This is considered to be interim action until final action is
identified, at which time the FAA may consider further rulemaking.
Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment thereon were
impracticable and contrary to the public interest, and good cause
existed to make the AD effective immediately by individual telegrams
issued on August 29, 1995, to all known U.S. owners and operators of
Lockheed Model L-1011-385 series airplanes. These conditions still
exist, and the AD is hereby published in the Federal Register as an
amendment to section 39.13 of the Federal Aviation Regulations (14 CFR
39.13) to make it effective to all persons.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 95-NM-153-AD.'' The postcard will be date stamped and
returned to the commenter.
The regulations adopted herein will not have substantial direct
effects on the States, on the relationship between the national
government and the States, or
[[Page 47466]]
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 final rule does not have sufficient
federalism implications to warrant the preparation of a Federalism
Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, may be obtained from 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.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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 USC 106(g), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
95-18-52 LOCKHEED: Amendment 39-9366. Docket 95-NM-153-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 (f) of this AD 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 fatigue cracking which could lead to failure of the
fittings that attach the aft pressure bulkhead to the fuselage
stringers, and could result in rapid decompression of the airplane
during flight, accomplish the following:
(a) Perform a detailed visual inspection to detect cracking of
the fittings that attach the aft pressure bulkhead to the fuselage
stringers (hereinafter referred to as ``fittings'') at stringers 1
through 10 (right side) and at stringers 64 through 56 (left side),
at the later of the times specified in either paragraph (a)(1) or
(a)(2) of this AD.
(1) Prior to the accumulation of 20,000 total flight cycles; or
(2) Within the next 25 flight cycles or 10 days after the
effective date of this AD, whichever occurs earlier.
(b) If cracking is detected in the fitting at either stringer 10
or stringer 56, prior to further flight, perform a detailed visual
inspection to detect cracking of the next adjacent fitting (i.e., at
stringer 11 or 55). If cracking is detected in that fitting, prior
to further flight, perform a detailed visual inspection to detect
cracking of the next adjacent fitting (i.e., at stringer 12 or 54).
If cracking is detected in that fitting, prior to further flight,
continue to perform detailed visual inspections to detect cracking
of the next adjacent fitting(s) until such a fitting is found to be
free of cracks.
(c) If any cracked fitting is detected during the inspections
required by either paragraph (a) or (b) of this AD, prior to further
flight, accomplish the requirements of paragraphs (c)(1) and (c)(2)
of this AD.
(1) Replace the cracked fitting with a new fitting, or with a
serviceable fitting on which a detailed visual inspection has been
performed previously to detect cracking and has been found to be
free of cracks; and
(2) Perform a detailed visual inspection to detect cracking in
the radius at the lower end of the vertical leg of the bulkhead T-
shaped frame between the stringer locations on either side of the
stringer having the cracked fitting. If any cracked T-shaped frame
is detected, prior to further flight, repair in accordance with a
method approved by the Manager, Atlanta Aircraft Certification
Office, FAA, Small Airplane Directorate.
(d) Repeat the inspections and other necessary actions required
by paragraphs (a), (b), and (c) of this AD at intervals not to
exceed 1,800 flight cycles or 3,000 flight hours, whichever occurs
earlier.
(e) Within 10 days after accomplishing the initial inspections
required by paragraphs (a) and (c) of this AD, submit a report of
the inspection results (both positive and negative findings) to the
Manager, Atlanta Aircraft Certification Office, FAA, Small Airplane
Directorate, Campus Building, 1701 Columbia Avenue, suite 2-160,
College Park, Georgia 30337-2748; telephone (404) 305-7340; fax
(404) 305-7348. The report must include, at a minimum, the total
number of flight cycles accumulated on the airplane having the
cracked fitting or cracked T-shaped frame, and identification of the
location on the airplane where the cracked fitting or T-shaped frame
was found, if any. 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.
(f) 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). 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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
(g) 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.
(h) This amendment becomes effective on September 28, 1995, to
all persons except those persons to whom it was made immediately
effective by telegraphic AD T95-18-52, issued on August 29, 1995,
which contained the requirements of this amendment.
Issued in Renton, Washington, on September 6, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-22591 Filed 9-12-95; 8:45 am]
BILLING CODE 4910-13-U
