[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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[[Page 47465]]



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