[Federal Register Volume 61, Number 181 (Tuesday, September 17, 1996)]
[Proposed Rules]
[Pages 48864-48866]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-23709]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-99-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9, DC-9-80 
and C-9 (Military) Series Airplanes, and Model MD-88 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-9, DC-9-80 and C-9 (military) series airplanes, and Model MD-88 
airplanes. This proposal would require either installation of external 
protective doublers between the outboard flight spoiler actuators and 
the aft spar webs of the wings, or replacement of the pistons of the 
outboard flight spoiler actuators with improved pistons. This proposal 
is prompted by reports of failure of the piston of the outboard flight 
spoiler actuator due to fatigue at the clevis end of the upper lug 
mounting hole of the piston. The actions specified by the proposed AD 
are intended to prevent such failure of the piston and the consequent 
puncturing of the aft spar web. This condition, if not corrected, could 
result in fuel leakage and reduced structural integrity of the wings.

DATES: Comments must be received by October 28, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-99-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this

[[Page 48865]]

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 at the FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Brent Bandley, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(310) 627-5237; 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-99-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-99-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that the pistons of the 
outboard flight spoiler actuators on the left and right wings of 
McDonnell Douglas Model DC-9, DC-9-80, or MD-88 series airplanes 
failed. Investigation revealed that fatigue of the clevis end of the 
upper lug mounting hole on the piston caused the pistons to fail. Such 
failure can result in the failed piston puncturing the aft spar web of 
the wing. This condition, if not corrected, could result in fuel 
leakage and reduced structural integrity of the wings.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin DC9-27-300, Revision 02, dated June 29, 1995, which describes 
procedures for installation of an external protective doubler between 
the aft spar web and the piston of the outboard flight spoiler actuator 
on the wings; and procedures for replacement of the pistons of outboard 
flight spoiler actuators with improved pistons of higher strength. 
Installing a protective doubler or replacing the spoiler actuator 
piston will minimize the possibility of a failed piston puncturing a 
fuel tank and reducing the structural integrity of the wing.

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 either installation of external protective 
doublers between the aft spar webs and the pistons of the outboard 
flight spoiler actuators on the wings, or replacement of the pistons of 
the outboard flight spoiler actuators with improved pistons. The 
actions would be required to be accomplished in accordance with the 
service bulletin described previously.

Cost Impact

    There are approximately 1,571 Model DC-9, DC-9-80, and C-9 
(military) series airplanes, and Model MD-88 airplanes of the affected 
design in the worldwide fleet. The FAA estimates that 1,047 airplanes 
of U.S. registry would be affected by this proposed AD.
    The proposed installation of external doublers would take 
approximately 14 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $1,500 per airplane. Based on these figures, the cost 
impact of the installation of external doublers proposed by this AD on 
U.S. operators is estimated to be $2,340 per airplane.
    The proposed replacement of the pistons of the outboard flight 
spoiler actuators would take approximately 12 work hours per airplane 
to accomplish, at an average labor rate of $60 per work hour. Required 
parts would cost approximately $5,180 per airplane. Based on these 
figures, the cost impact of the replaced of the pistons proposed by 
this AD on U.S. operators is estimated to be $5,900 per airplane.
    These cost impact figures 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:

[[Page 48866]]

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-99-AD.

    Applicability: Model DC-9, Model DC-9-80 and C-9 (military) 
series airplanes, and Model MD-88 airplanes; as listed in McDonnell 
Douglas Service Bulletin DC9-27-300, Revision 02, dated June 29, 
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 (b) 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 fuel leakage and reduced structural integrity of the 
wings due to puncturing of the wings by a failed piston of the 
outboard flight spoiler actuator, accomplish the following:
    (a) Prior to the accumulation of 5,000 landings after the 
effective date of this AD, accomplish the actions specified in 
either paragraph (a)(1) or (a)(2) of this AD, in accordance with 
McDonnell Douglas Service Bulletin DC9-27-300, Revision 02, dated 
June 29, 1995.

    Note 2: Installation of McDonnell Douglas flight spoiler 
actuator assembly, part number (P/N) 5915900-5525, on the right and 
left wings prior to the effective date of this AD is considered 
acceptable for compliance with the requirements of this paragraph.
    (1) Install external protective doublers between the outboard 
flight spoiler actuators and the aft spar webs of the left and right 
wings; or
    (2) Replace the pistons of the outboard flight spoiler actuators 
on the left and right wings with improved pistons,
    (b) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (c) 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 10, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-23709 Filed 9-16-96; 8:45 am]
BILLING CODE 4910-13-U