[Federal Register Volume 63, Number 173 (Tuesday, September 8, 1998)]
[Proposed Rules]
[Pages 47443-47445]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24063]



[[Page 47443]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-109-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series 
Airplanes, Model MD-88 Airplanes, and Model MD-90-30 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-9-80 series airplanes, Model MD-88 airplanes, and Model MD-90-30 
airplanes. This proposal would require repetitive inspections to detect 
cracking of the main landing gear (MLG) shock strut pistons, and 
replacement of a cracked piston with a new or serviceable part. This 
proposal is prompted by reports indicating that, while an airplane was 
positioned on the taxiway, the right MLG shock strut piston failed due 
to fatigue cracking. The actions specified by the proposed AD are 
intended to detect and correct such fatigue cracking, which could 
result in failure of the piston, and consequent damage to the airplane 
structure or injury to the passengers and flightcrew.

DATES: Comments must be received by October 23, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-109-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 The Boeing Company, Douglas Products Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, Dept. 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, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5237; fax (562) 
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 98-NM-109-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-114, Attention: Rules 
Docket No. 98-NM-109-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report of failure of the shock strut piston 
of the right main landing gear (MLG) while a McDonnell Douglas Model 
DC-9-80 series airplane was positioned on the taxiway. (A similar 
incident also occurred in 1991.) The report indicated that the affected 
piston on the airplane had accumulated 22,484 total flight cycles. 
Investigation revealed that the cause of this failure was attributed to 
a large fatigue crack that had propagated across the bottom of the MLG 
shock strut piston. The crack initiated near the jackball, which is 
located on the bottom of the MLG shock strut piston and is used by 
operators to jack up the airplane. This condition, if not corrected, 
could result in failure of the MLG shock strut piston, and consequent 
damage to the airplane structure or injury to the passengers and 
flightcrew.
    The subject area on certain McDonnell Douglas Model MD-88 airplanes 
and Model MD-90-30 airplanes is identical to that of the affected Model 
DC-9-80 series airplanes. Therefore, all of these airplanes may be 
subject to the same unsafe condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Alert Service 
Bulletins MD80-32A308, dated March 5, 1998, and MD80-32A308, Revision 
01, dated May 12, 1998 [for Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-
9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 
airplanes]; and MD90-32A030, dated March 26, 1998, and MD90-32A030, 
Revision 01, dated May 11, 1998 (for Model MD-90-30 airplanes). These 
alert service bulletins describe procedures for repetitive fluorescent 
dye penetrant and fluorescent magnetic particle inspections to detect 
cracking of the MLG shock strut piston, and replacement of any cracked 
piston with a new or serviceable part.

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 accomplishment of the actions specified in 
the alert service bulletins described previously.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised that it currently is developing a modification that will 
positively address the unsafe condition addressed by this AD. Once this 
modification is developed, approved, and available, the FAA may 
consider additional rulemaking.

Cost Impact

    There are approximately 1,250 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 828 airplanes of U.S. 
registry would be affected by this proposed AD, that it

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would take approximately 4 work hours per airplane to accomplish the 
proposed inspection, and that the average labor rate is $60 per work 
hour. Based on these figures, the cost impact of the inspection 
proposed by this AD on U.S. operators is estimated to be $198,720, or 
$240 per airplane, per inspection cycle.
    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.
    Should an operator be required to accomplish the proposed 
replacement of an MLG shock strut piston, it would take approximately 
16 work hours per airplane to accomplish, at an average labor rate of 
$60 per work hour. Required parts would cost approximately $107,070 per 
airplane. Based on these figures, the cost impact of the replacement 
proposed by this AD on U.S. operators is estimated to be $108,030 per 
airplane.

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 98-NM-109-AD.

    Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 
(MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 
airplanes, as listed in McDonnell Douglas Alert Service Bulletin 
MD80-32A308, Revision 01, dated May 12, 1998; and Model MD-90-30 
airplanes, as listed in McDonnell Douglas Alert Service Bulletin 
MD90-32A030, Revision 01, dated May 11, 1998; 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 request approval for an 
alternative method of compliance in accordance with paragraph (e) 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 detect and correct fatigue cracking of the main landing gear 
(MLG) shock strut pistons, which could result in failure of the 
piston, and consequent damage to the airplane structure or injury to 
the passengers and flightcrew, accomplish the following:
    (a) Perform fluorescent dye penetrant and fluorescent magnetic 
particle inspections to detect cracking of an MLG shock strut 
piston, in accordance with McDonnell Douglas Alert Service Bulletin 
MD80-32A308, dated March 5, 1998, or MD80-32A308, Revision 01, dated 
May 12, 1998 [for Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 
(MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 
airplanes]; or MD90-32A030, dated March 26, 1998, or MD90-32A030, 
Revision 01, dated May 11, 1998 (for Model MD-90-30 airplanes); as 
applicable. Perform the inspections at the later of the times 
specified in paragraphs (a)(1) and (a)(2) of this AD.
    (1) Prior to the accumulation of 10,000 total landings on an MLG 
shock strut piston, or within 6 months after the effective date of 
this AD, whichever occurs later.
    (2) Within 2,500 landings after a major overhaul and initial 
inspection of the MLG shock strut piston accomplished prior to the 
effective date of this AD, in accordance with McDonnell Douglas All 
Operator Letter 9-2153 [for Model DC-9-81 (MD-81), DC-9-82 (MD-82), 
DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-
88 airplanes], or McDonnell Douglas Component Maintenance Manual, 
Chapter 32-17-01 (for Model MD-90-30 airplanes).
    (b) Condition 1. If any cracking is detected, prior to further 
flight, replace any cracked MLG shock strut piston with a new or 
serviceable piston, in accordance with McDonnell Douglas Alert 
Service Bulletin MD80-32A308, dated March 5, 1998, or MD80-32A308, 
Revision 01, dated May 12, 1998 [for Model DC-9-81 (MD-81), DC-9-82 
(MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, and 
Model MD-88 airplanes]; or MD90-32A030, dated March 26, 1998, or 
MD90-32A030, Revision 01, dated May 11, 1998 (for Model MD-90-30 
airplanes); as applicable. Repeat the fluorescent dye penetrant and 
fluorescent magnetic particle inspections thereafter at intervals 
not to exceed 2,500 landings.
    (c) Condition 2. If no cracking is detected, repeat the 
fluorescent dye penetrant and fluorescent magnetic particle 
inspections thereafter at intervals not to exceed 2,500 landings, in 
accordance with McDonnell Douglas Alert Service Bulletin MD80-
32A308, dated March 5, 1998, or MD80-32A308, Revision 01, dated May 
12, 1998 [for Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-
83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 
airplanes]; or MD90-32A030, dated March 26, 1998, or MD90-32A030, 
Revision 01, dated May 11, 1998 (for Model MD-90-30 airplanes); as 
applicable.
    (d) As of the effective date of this AD, no person shall install 
on any airplane a replacement MLG shock strut piston, part number 
5935347-509, -511, or -513, or an MLG assembly from an operator's 
spares inventory, unless those components have been inspected in 
accordance with the requirements specified by paragraph (a) of this 
AD.
    (e) 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.

    (f) 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.


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    Issued in Renton, Washington, on September 1, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-24063 Filed 9-4-98; 8:45 am]
BILLING CODE 4910-13-P