[Federal Register Volume 61, Number 169 (Thursday, August 29, 1996)]
[Proposed Rules]
[Pages 45375-45377]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22011]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-135-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10-10, -30, 
and -40 Series Airplanes, and KC-10 (Military) 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, -30 and -40 series airplanes, and KC-10 (military) series 
airplanes. This proposal would require repetitive high frequency eddy 
current (HFEC) inspections to detect cracks in the number 4 banjo 
fitting on the rear spar of the vertical stabilizer, and repair and 
modification of the vertical stabilizer, if necessary. It also would 
require the installation of a modification as terminating action for 
the repetitive inspections. This proposal is prompted by reports of 
failed attach bolts and cracking found in the area of the number 4 
banjo fitting, which were caused by higher than normal operating 
stresses. The actions specified by the proposed AD are intended to 
prevent reduction in the structural integrity of this fitting due to 
failed bolts and cracking. This condition, if not corrected, could 
ultimately lead to reduced controllability of the airplane during 
flight and ground operations.

DATES: Comments must be received by October 7, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-135-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, or the FAA, Los Angeles Aircraft 
Certification Office, Transport Airplane Directorate, 3960 Paramount 
Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Ron Atmur, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(310) 627-5224; 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 96-NM-135-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. 96-NM-135-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of failure of the bolts that connect 
the lower web of the pylon of the number 2 tail engine to the number 4 
banjo fitting on the rear spar of the vertical stabilizer on McDonnell 
Douglas Model DC-10 series airplanes. Such failures occurred on 
airplanes that had been operated for 10,300 to 16,000 total flight 
hours, and had made 4,400 to 7,000 landings. In addition, an operator 
found a crack in the aft flange of the number 4 banjo fitting; this 
airplane had been operated for 48,500 total flight hours and had made 
10,418 landings. These discrepancies have been attributed to higher 
than normal stresses on the airplane in this area of the number 4 banjo 
fitting, resulting from excessive maneuvers, excessive turbulence, and 
hard landings. Such discrepancies, if not corrected, could result in a 
reduction in the structural integrity of the number 4 banjo fitting 
and, ultimately, could lead to reduced controllability of the airplane 
during flight and ground operations.

[[Page 45376]]

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin DC10-54-096, Revision 03, dated February 6, 1996, which 
describes procedures for conducting repetitive high frequency eddy 
current (HFEC) inspections of the upper and lower surface of the aft 
flange of the number 4 banjo fitting on the rear spar of the vertical 
stabilizer; procedures for repairs; if necessary; and procedures for 
modification of the vertical stabilizer in the vicinity of such 
fitting. The repairs and modification entail trimming of parts; 
replacing angles, shields, and spacers; and modifying the fireseal. 
These actions will reduce the loads being transmitted from the pylon of 
the number 2 tail engine to the rear spar of the vertical stabilizer; 
such reduction of loads will minimize the possibility of bolt failure 
and cracking of the flange of the number 4 banjo fitting. 
Accomplishment of the repairs and modification eliminates the need for 
repetitive HFEC inspections of this area.

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 require repetitive HFEC inspections of the upper and 
lower surfaces of the aft flange of the number 4 banjo fitting on the 
rear spar of the vertical stabilizer. If cracks are detected, repairs 
and modification of the vertical stabilizer in the vicinity of the 
number 4 banjo fitting would be required; accomplishment of these 
actions would terminate the requirement for repetitive HFEC 
inspections. This AD also would require that the modification be 
installed eventually on all airplanes as terminating action for the 
repetitive HFEC inspections. These actions would be required to be 
accomplished in accordance with the service bulletin described 
previously.

Cost Impact

    There are approximately 376 Model DC-10-10, -30 and -40 series 
airplanes and KC-10 (military) series airplanes of the affected design 
in the worldwide fleet. The FAA estimates that 230 airplanes of U.S. 
registry would be affected by this proposed AD.
    It would take approximately 2 work hours per airplane to accomplish 
each proposed inspection; the average labor rate is $60 per work hour. 
Based on these figures, the cost impact of the proposed inspection 
requirement on U.S. operators of airplanes is estimated to be $27,600, 
or $120 per airplane, per inspection.
    It would take approximately 34 hours to accomplish the proposed 
modification that would terminate the requirement for repetitive HFEC 
inspections. Required parts to accomplish such modification would cost 
approximately $3,875 per airplane for ``Group 1'' airplanes, as listed 
in the service bulletin; and approximately $3,427 per airplane for 
``Group 2'' airplanes, as listed in the service bulletin. Based on 
these figures, the cost impact of the proposed modification requirement 
on U.S. operators is estimated to be $5,915 per Group 1 airplane and 
$5,467 per Group 2 airplane.
    The cost impact figures discussed above are 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.

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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

McDonnell Douglas: Docket 96-NM-135-AD.
    Applicability: Model DC-10-10, -30, and -40 series airplanes, 
and KC-10 (military) series airplanes; as listed in McDonnell 
Douglas Service Bulletin DC10-54-096, Revision 03, dated February 6, 
1996; 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 reduction in the structural integrity of the number 4 
banjo fitting on the rear spar of the vertical stabilizer, which 
could ultimately result in a reduction in the ability to control the 
airplane during flight and ground operations, accomplish the 
following:
    (a) Prior to the accumulation of 5,000 total landings, or within 
1,500 landings after the effective date of this AD, whichever occurs 
later, perform a high frequency eddy current (HFEC) inspection to 
detect cracks in the upper and lower surface of the aft flange of 
the number 4 banjo fitting on the rear spar of the vertical 
stabilizer, in accordance with McDonnell Douglas Service Bulletin 
DC10-54-096, Revision 03, dated February 6, 1996.
    (1) If no crack is found, repeat the HFEC inspection thereafter 
at intervals not to exceed 1,500 landings.
    (2) If any crack is found, prior to further flight, repair the 
crack and install the modification in accordance with the service 
bulletin.
    (b) Within 5 years after the effective date of this AD, modify 
the vertical stabilizer in the area of the number 4 banjo fitting on 
the rear spar, in accordance with McDonnell Douglas Service Bulletin 
DC10-54-096, Revision 03, dated February 6, 1996. Accomplishment of 
this modification constitutes terminating action for the repetitive 
HFEC inspections required by paragraph (a)(1) of this AD.

[[Page 45377]]

    (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 August 22, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-22011 Filed 8-28-96; 8:45 am]
BILLING CODE 4910-13-U