[Federal Register Volume 61, Number 61 (Thursday, March 28, 1996)]
[Proposed Rules]
[Pages 13787-13789]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7549]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-204-AD]


Airworthiness Directives; McDonnell Douglas Model DC-10-10 and -
15 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 certain McDonnell Douglas Model 
DC-10-10 and -15 series airplanes. This proposal would require 
repetitive inspections to detect cracks in the bulkhead tee caps, and 
repair and follow-on actions, if necessary. The proposal would also 
provide for an optional terminating modification for the repetitive 
inspections. This proposal is prompted by reports of cracking in the 
bulkhead tee caps at a fuselage station in the area of certain 
longerons due to fatigue. The actions specified by the proposed AD are 
intended to prevent such fatigue cracking, which could result in loss 
of pressurization and damage to adjacent structure.

DATES: Comments must be received by May 21, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-204-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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Technical Publications 
Business Administration, Department C1-L51 (2-60). This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington.


[[Page 13788]]

FOR FURTHER INFORMATION CONTACT: Maureen Moreland, Aerospace Engineer, 
Systems and Equipment Branch, ANM-120L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712; telephone (310) 627-5238; fax (310) 627-5210.

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 95-NM-204-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. 95-NM-204-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On November 6, 1995, the FAA issued AD 95-23-09, Amendment 39-9429 
(60 FR 61649, December 1, 1995), which is applicable to McDonnell 
Douglas DC-10 series airplanes and Model KC-10A (military) airplanes. 
That AD requires the implementation of a Structural Inspection Document 
(SID) program of structural inspections to detect fatigue cracking, and 
repair or replacement, as necessary, to ensure the continued 
airworthiness of these airplanes as they approach the manufacturer's 
original fatigue design life goal. Among other requirements, AD 95-23-
09 requires inspection of the bulkhead tee cap at station Y=1156.000 
under the fleet leader operator sampling criteria. [The bulkhead tee 
cap at station Y=1156.000 is designated as Principal Structural 
Elements (PSE) 53.10.041B and 53.10.042B in McDonnell Douglas Report 
Number L26-012, ``DC-10 Supplemental Inspection Document,'' which is 
referenced in AD 95-23-09 as the appropriate source of service 
information.] The fatigue life threshold (Nth) for this PSE is 
31,898 landings. The sampling period for this PSE started in September 
1989, and will end in June 1996. Sampling inspections are to be 
accomplished within that interval for airplanes in the candidate fleet 
that have accumulated more than 15,949 total landings(Nth/2).
    The FAA has received several reports of cracking in the bulkhead 
tee caps at fuselage station Y=1156.000 (left and right sides) in the 
area of longerons 38 and 41.0. The cracking was found on Model DC-10-10 
and -15 series airplanes that had accumulated between 56,394 and 72,931 
total flight hours and between 21,629 and 26,094 total landings. 
Investigation revealed that the cause of such cracking has been 
attributed to fatigue. The FAA has determined that additional 
inspections of this area will ensure that fatigue cracking is detected 
before it reaches a critical length. Fatigue cracking, if not detected 
and corrected in a timely manner, could result in loss of 
pressurization and damage to adjacent structure.
    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin DC10-53-168, dated August 9, 1995. The service bulletin 
describes procedures for repetitive eddy current and radiographic 
inspections to detect cracks in the bulkhead tee caps (left and right 
sides) between longerons 38.0 and 41.0 at fuselage station Y=1156.000, 
and repair and follow-on actions (i.e., repetitive inspections), if 
necessary.
    The service bulletin also describes an optional terminating 
preventative modification that would eliminate the need for the 
repetitive inspections. The modification includes cold working fastener 
holes and a follow-on inspection program. Accomplishment of the 
preventative modification will minimize the possibility of cracks 
developing in the subject area of the bulkhead tee cap.
    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 require repetitive eddy current and radiographic 
inspections to detect cracks in the bulkhead tee caps (left and right 
sides) between longerons 38.0 and 41.0 at fuselage station Y=1156.000, 
and repair and follow-on actions, if necessary. The proposed AD would 
provide for an optional terminating preventative modification that 
would constitute terminating action for the repetitive inspection 
requirements. The actions would be required to be accomplished in 
accordance with the service bulletin described previously.
    Operators should note that, although the service bulletin specifies 
that the manufacturer may be contacted for disposition of certain 
repair conditions, this proposal would require the repair of those 
conditions to be accomplished in accordance with a method approved by 
the Manager of the Los Angeles Aircraft Certification Office, FAA, 
Transport Airplane Directorate.
    There are approximately 133 McDonnell Douglas Model DC-10-10 and -
15 series airplanes of the affected design in the worldwide fleet. The 
FAA estimates that 121 airplanes of U.S. registry would be affected by 
this proposed AD, that it would take approximately 3 work hours per 
airplane to accomplish the proposed actions, and that the average labor 
rate is $60 per work hour. Based on these figures, the cost impact of 
the proposed AD on U.S. operators is estimated to be $21,780, or $180 
per airplane, per inspection cycle.
    The 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.
    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

[[Page 13789]]
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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

McDonnell Douglas: Docket 95-NM-204-AD.

    Applicability: Model DC-10-10 and -15 series airplanes, as 
listed in McDonnell Douglas Service Bulletin DC10-53-168, dated 
August 9, 1995; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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) 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 prevent fatigue cracking, which could result in loss 
of pressurization and damage to adjacent structure, accomplish the 
following:
    (a) Prior to the accumulation of 20,000 total landings, or 
within 1,500 landings after the effective date of this AD, whichever 
occurs later, perform an eddy current and radiographic inspection, 
as applicable, to detect cracks in the bulkhead tee caps (left and 
right sides) in the area of longerons 38.0 through 41.0 at fuselage 
station Y=1156.000, in accordance with McDonnell Douglas Service 
Bulletin DC10-53-168, dated August 9, 1995.
    (1) If no cracks are detected, repeat the inspections thereafter 
at intervals not to exceed 2,600 landings until paragraph (b) of 
this AD is accomplished.
    (2) If any crack is detected, prior to further flight, 
accomplish the repair specified in either paragraph (a)(2)(i) or 
(a)(2)(ii) of this AD.
    (i) Splice in a new bulkhead tee cap section at cracked area of 
bulkhead tee cap in accordance with the service bulletin. Within 
20,000 total landings after accomplishing this repair, perform eddy 
current inspections to detect cracks in accordance with the service 
bulletin. Repeat the inspections thereafter at intervals not to 
exceed 2,600 landings until paragraph (b) of this AD is 
accomplished. If any crack is detected, prior to further flight, 
repair it in accordance with a method approved by the Manager, Los 
Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate.
    (ii) Repair in accordance with a method approved by the Manager, 
Los Angeles ACO, FAA, Transport Airplane Directorate.
    (b) Terminating action for the repetitive inspections required 
by paragraphs (a)(1) and (a)(2)(ii) of this AD is as follows:
    (1) Accomplish the preventative modification and eddy current 
open hole inspection in accordance with Condition 1 (no cracks in 
bulkhead tee cap), Option 2, of the service bulletin. And
    (2) Within 14,450 total landings following accomplishment of the 
modification, perform an eddy current and radiographic inspection to 
detect cracks in accordance with Condition 1 (no cracks in bulkhead 
tee cap), Option 2, of the service bulletin.
    (i) If no cracks are detected, repeat the inspections thereafter 
at intervals not to exceed 3,950 landings.
    (ii) If any crack is detected, prior to further flight, repair 
it in accordance with a method approved by the Manager, Los Angeles 
ACO, FAA, Transport Airplane Directorate.
    (c) 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, Los Angeles Aircraft Certification 
Office (ACO), FAA, Transport 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, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (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 March 22, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-7549 Filed 3-27-96; 8:45 am]
BILLING CODE 4910-13-P