[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]
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