[Federal Register Volume 64, Number 52 (Thursday, March 18, 1999)]
[Rules and Regulations]
[Pages 13330-13333]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-6216]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-292-AD; Amendment 39-11077; AD 99-06-13]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series
Airplanes and Model MD-88 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain McDonnell Douglas Model DC-9-80 series
airplanes and Model MD-88 airplanes, that currently requires
inspection(s) to detect fatigue cracking of the shock strut cylinder of
the main landing gear (MLG), and replacement of any cracked shock strut
cylinder with a serviceable part. That AD also provides for
installation of brake line hydraulic restrictors on the MLG brake
systems, which, if accomplished, terminates the repetitive inspections.
This amendment requires that the subject inspection be accomplished
repetitively following installation of brake line hydraulic
restrictors. This amendment is prompted by an additional report of
fatigue cracking and subsequent fracturing of the shock strut cylinder
of the MLG. The actions specified by this AD are intended to prevent
collapse of the MLG due to fracturing of the shock strut cylinder.
[[Page 13331]]
DATES: Effective April 22, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of April 22, 1999.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Aircraft Group, Long Beach 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 Federal Aviation Administration
(FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue,
SW., Renton, Washington; or at the FAA, Transport Airplane Directorate,
Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard,
Lakewood, California; or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC.
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
(562) 627-5237; fax (562) 627-5210.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 95-22-06,
amendment 39-9413 (60 FR 54417, October 24, 1995), which is applicable
to certain McDonnell Douglas Model DC-9-80 series airplanes and Model
MD-88 airplanes, was published in the Federal Register on July 30, 1998
(63 FR 40666). The action proposed to continue to require inspection(s)
to detect fatigue cracking of the shock strut cylinder of the main
landing gear (MLG), and replacement of any cracked shock strut cylinder
with a serviceable part. That action also proposed to continue to
provide for installation of brake line hydraulic restrictors on the MLG
brake systems, which, if accomplished, terminates the repetitive
inspections. That action proposed to require that the subject
inspection be accomplished repetitively following installation of brake
line hydraulic restrictors.
Comments Received
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposed Rule
Several commenters support the proposed rule.
Request To Revise Wording
One commenter requests that the phrase ``for airplanes'' in
paragraphs (a)(1), (a)(2), and (a)(3) of the proposed AD be revised to
``for MLG shock strut cylinders.'' The commenter points out that MLG's
are replaceable units that can be ``time continued'' on a different
airplane. The FAA concurs. The FAA's intent was that compliance time of
those paragraphs be specified in the landings accumulated on MLG's
since accomplishment of the brake line hydraulic restrictor
installation, rather than the landings that an airplane had
accumulated. Therefore, the FAA has revised paragraphs (a)(1), (a)(2),
and (a)(3) of the final rule to clarify this point.
Requests To Revise Repetitive Inspection Intervals
One commenter requests that the repetitive inspection interval of
the proposed AD be extended from 1,200 landings to 2,000 landings. The
commenter states that such an extension would allow most inspections to
occur within its check hangar environment.
The FAA does not concur with the commenter's request. The commenter
provided no technical justification for revising this interval as
requested. Fatigue cracking and subsequent fracturing of the shock
strut cylinder of the MLG is a significant safety issue, and the FAA
has determined that the inspection interval, as proposed, is warranted,
based on the effectiveness of the inspection procedure to detect
cracks, and the rate of crack growth in the shock strut cylinder of the
MLG. The FAA considered not only those safety issues in developing an
appropriate compliance time for this action, but the recommendations of
the manufacturer, the availability of any necessary repair parts, and
the practical aspect of accomplishing the required inspection within an
interval of time that parallels normal scheduled maintenance for the
majority of affected operators. However, under the provisions of
paragraph (d)(1) of the final rule, the FAA may approve requests for
adjustments to the compliance time if data are submitted to
substantiate that such an adjustment would provide an acceptable level
of safety.
One commenter requests that the FAA revise the proposed AD to
simplify and clarify that inspections should be performed at a minimum
of 4,800 cycles past restrictor installation. The commenter suggests
that the proposed AD be revised to read, ``Perform repetitive
inspections at intervals not to exceed 1,200 landings until a minimum
of 4,800 landings has accumulated since brake line restrictor
installation. A minimum of two (2) repetitive inspections, with at
least 1,000 cycles accrued between inspections, shall be performed
regardless of the total number of cycles accumulated since restrictor
installation.'' The commenter states that such a statement will ensure
that inspections are performed past 4,800 cycles from restrictor
installation and will allow credit for inspections performed prior to
issuance of McDonnell Douglas Alert Service Bulletin MD80-32A286,
Revision 02, dated October 2, 1997.
The FAA does not concur with the commenter's request. The FAA
points out that the subject repetitive inspection intervals are
essentially identical to those specified in McDonnell Douglas Alert
Service Bulletin MD80-32A286, Revision 03, dated May 28, 1998 (which is
referenced in the proposed AD as the appropriate source of service
information for accomplishment of the required actions). The FAA finds
that using wording that is significantly different from that of the
alert service bulletin may cause more confusion to operators.
Therefore, the FAA finds that no change to the final rule is necessary.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
There are approximately 1,011 McDonnell Douglas Model DC-9-80
series airplanes and Model MD-88 airplanes of the affected design in
the worldwide fleet. The FAA estimates that 625 airplanes of U.S.
registry will be affected by this AD.
The dye penetrant and magnetic particle inspections that are
required in this AD action will take approximately 4 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the dye penetrant and
magnetic particle inspections required by this AD on U.S. operators is
estimated to be $150,000, or $240 per airplane, per inspection cycle.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the requirements of this AD
action, and that no operator would accomplish
[[Page 13332]]
those actions in the future if this AD were not adopted.
Regulatory Impact
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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 removing amendment 39-9413 (60 FR
54417, October 24, 1995), and by adding a new airworthiness directive
(AD), amendment 39-11077, to read as follows:
99-06-13 McDonnell Douglas: Amendment 39-11077. Docket 97-NM-292-
AD. Supersedes AD 95-22-06, Amendment 39-9413.
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
MD80-32A286, dated September 11, 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
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 (d)(1)
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 collapse of the main landing gear (MLG) due to
fracturing of the shock strut cylinder, accomplish the following:
Note 2: Where there are differences between the referenced alert
service bulletin and the AD, the AD prevails.
Inspections
(a) Perform dye penetrant and magnetic particle inspections to
detect cracking of the shock strut cylinder of the MLG, in
accordance with McDonnell Douglas Alert Service Bulletin MD80-
32A286, Revision 03, dated May 28, 1998; at the time specified in
paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable.
Note 3: Inspections accomplished prior to the effective date of
this AD in accordance with McDonnell Douglas Alert Service Bulletin
MD80-32A286, Revision 02, dated October 2, 1997, are considered
acceptable for compliance with paragraph (a) of this AD.
(1) For MLG shock strut cylinders that, as of the effective date
of this AD, have accumulated less than 1,200 landings since
accomplishment of the brake line hydraulic restrictor installation:
Inspect within 1,200 landings after the effective date of this AD.
Repeat the inspections thereafter at intervals not to exceed 1,200
landings for a total of 4 inspections.
(2) For MLG shock strut cylinders that, as of the effective date
of this AD, have accumulated greater than or equal to 1,200 landings
and less than 2,400 landings since accomplishment of the brake line
hydraulic restrictor installation: Inspect within 1,200 landings
after the effective date of this AD. Repeat the inspections
thereafter at intervals not to exceed 1,200 landings for a total of
3 inspections.
(3) For MLG shock strut cylinders that, as of the effective date
of this AD, have accumulated greater than or equal to 2,400 landings
since accomplishment of the brake line hydraulic restrictor
installation: Inspect within 1,200 landings after the effective date
of this AD. Repeat the inspections thereafter at intervals not to
exceed 1,200 landings for a total of 2 inspections.
Corrective Actions
(b) If any cracking is detected during any inspection required
by paragraph (a) of this AD, prior to further flight, accomplish
either paragraph (b)(1) or (b)(2) of this AD in accordance with
McDonnell Douglas Alert Service Bulletin MD80-32A286, Revision 03,
dated May 28, 1998.
(1) Replace the shock strut cylinder with a crack-free
serviceable part and, thereafter, repeat the inspections required by
paragraph (a) of this AD, at the time specified in paragraph (a)(1),
(a)(2), or (a)(3) of this AD, as applicable. Or
(2) Replace the shock strut cylinder with a new shock strut
cylinder. Accomplishment of the replacement constitutes terminating
action for the repetitive inspection requirements of paragraph (a)
of this AD.
Note 4: Replacements accomplished prior to the effective date of
this AD in accordance with McDonnell Douglas Alert Service Bulletin
MD80-32A286, Revision 02, dated October 2, 1997, are considered
acceptable for compliance with paragraph (b) of this AD.
Spares
(c) As of the effective date of this AD, no person shall install
on any airplane an MLG shock strut cylinder or MLG assembly unless
that part has been inspected and found to be crack free, in
accordance with McDonnell Douglas Alert Service MD80-32A286,
Revision 02, dated October 2, 1997, or Revision 03, dated May 28,
1998.
Alternative Methods of Compliance
(d)(1) 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 5: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(d)(2) Alternative methods of compliance, approved previously in
accordance with AD 95-22-06, amendment 39-9413, are approved as
alternative methods of compliance with this AD.
Special Flight Permits
(e) 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.
Incorporation by Reference
(f) The actions shall be done in accordance with McDonnell
Douglas Alert Service Bulletin MD80-32A286, Revision 03, dated May
28, 1998. This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51. Copies may be obtained from Boeing Commercial
Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long
Beach, California 90846, Attention: Technical Publications Business
Administration, Dept. C1-L51 (2-60). Copies may be inspected at the
FAA, Transport
[[Page 13333]]
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; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
(g) This amendment becomes effective on April 22, 1999.
Issued in Renton, Washington, on March 9, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-6216 Filed 3-17-99; 8:45 am]
BILLING CODE 4910-13-U