[Federal Register Volume 64, Number 194 (Thursday, October 7, 1999)]
[Rules and Regulations]
[Pages 54515-54517]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25766]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-268-AD; Amendment 39-11350; AD 99-21-07]
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: Final rule.

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SUMMARY: This amendment supersedes two existing airworthiness 
directives (AD), applicable to certain McDonnell Douglas Model DC-9, 
DC-9-80, and C-9 (military) series airplanes, and Model MD-88 
airplanes, that currently require installation of hydraulic line 
restrictors in the main landing gear (MLG), and modification or 
replacement of the left and right MLG hydraulic damper assemblies. This 
amendment requires an additional modification of the MLG hydraulic 
damper assemblies, or replacement of the MLG hydraulic damper 
assemblies with modified and reidentified hydraulic damper assemblies. 
This amendment is prompted by reports indicating that MLG hydraulic 
damper assemblies removed for overhaul had failed or damaged spring 
retainers, due to insufficient material thickness of the spring 
retainers. The actions specified by this AD are intended to prevent 
failure of the hydraulic damper assemblies of the MLG, which could 
result in vibration damage and collapse of the MLG.

DATES: Effective November 12, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 12, 1999.
    The incorporation by reference of McDonnell Douglas Service 
Bulletin DC9-32-289, dated March 7, 1996, listed in the regulations was 
approved previously by the Director of the Federal Register as of 
November 14, 1996 (61 FR 53042, October 10, 1996).
    The incorporation by reference of certain other publications listed 
in the regulations was approved previously by the Director of the 
Federal Register as of February 26, 1996 (61 FR 2407, January 26, 
1996).

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. 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: Albert Lam, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5346; 
fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 96-01-09, 
amendment 39-9485 (61 FR 2407, January 26, 1996), and AD 96-21-01, 
amendment 39-9777 (61 FR 53042, October 10, 1996), which are applicable 
to certain McDonnell Douglas Model DC-9, DC-9-80, and C-9 (military) 
series airplanes, and Model MD-88 airplanes, was published in the 
Federal Register on July 23, 1999 (64 FR 39944). The action proposed to 
require an additional modification of the main landing gear (MLG) 
hydraulic damper assemblies, or replacement of the MLG hydraulic damper 
assemblies with modified and reidentified hydraulic damper assemblies.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.
    The commenter supports the proposed rule.

Conclusion

    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    There are approximately 2,015 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 1,145 airplanes of U.S. 
registry will be affected by this AD.
    The installation that is currently required by AD 96-01-09, and 
retained in this AD, takes approximately 4 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Required 
parts cost approximately $928 per airplane. Based on these figures, the 
cost impact of the currently required installation on U.S. operators is 
estimated to be $1,168 per airplane.
    The modification that is currently required by AD 96-01-09, and 
retained in this AD, takes approximately 6 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Required 
parts cost approximately $4,000 per airplane. Based on these figures, 
the cost impact of the currently required modification on U.S. 
operators is estimated to be $4,360 per airplane.
    The replacement that is currently required by AD 96-21-01, and 
retained in this AD, takes approximately 6 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Required 
parts cost approximately $11,139 per airplane (two assemblies at $5,569 
each). Based on these figures, the cost impact of the currently 
required replacement on U.S. operators is estimated to be $11,499 per 
airplane.
    The modification that is currently required by AD 96-21-01, and 
retained in this AD, takes approximately 11 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Required 
parts cost approximately $2,907 per airplane. Based on these figures, 
the cost impact of the currently required modification on U.S. 
operators is estimated to be $3,567 per airplane.
    The modification or replacement that is required in this AD action 
will take approximately 18 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts will cost 
approximately $608 per airplane. Based on these figures, the cost 
impact of the modification required by this AD on

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U.S. operators is estimated to be $1,932,760, or $1,688 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the 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 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 39-9485 (61 FR 
2407, January 26, 1996), and amendment 39-9777 (61 FR 53042, October 
10, 1996), and by adding a new airworthiness directive (AD), amendment 
39-11350, to read as follows:

99-21-07  McDonnell Douglas: Amendment 39-11350. Docket 98-NM-268-
AD. Supersedes AD 96-01-09, Amendment 39-9485; and AD 96-21-01, 
Amendment 39-9777.

    Applicability: Model DC-9-81 (MD-81), -82 (MD-82), -83 (MD-83), 
and 87 (MD-87) series airplanes, and Model MD-88 airplanes; as 
listed in McDonnell Douglas Service Bulletins MD80-32-276 and MD80-
32-278, both dated March 31, 1995; and Model DC-9-10, -20, -30, -40, 
and -50; and C-9 (military) series airplanes, as listed in McDonnell 
Douglas Service Bulletin DC9-32-289, dated March 7, 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 
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 (h) 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 failure of the hydraulic damper assemblies of the 
MLG, which could result in vibration damage and collapse of the MLG, 
accomplish the following:

Restatement of Requirements of AD 96-01-09

Modifications

    (a) For airplanes listed in McDonnell Douglas MD-80 Service 
Bulletin MD80-32-276, dated March 31, 1995, that have not been 
previously modified (installation of brake line restrictors) in 
accordance with McDonnell Douglas MD-80 Service Bulletin MD80-32-
246: Within 9 months after February 26, 1996 (the effective date of 
AD 96-01-09, amendment 39-9485), install filtered brake line 
restrictors in the MLG hydraulic brake system in accordance with 
McDonnell Douglas MD-80 Service Bulletin MD80-32-276, dated March 
31, 1995, or Revision 1, dated October 17, 1995.

    Note 2: Installation of filtered restrictors in accordance with 
the instructions specified in McDonnell Douglas MD-80 Alert Service 
Bulletin, MD80-A32-286, dated September 11, 1995, is considered 
acceptable for compliance with paragraph (a) of this AD.

    (b) For airplanes listed in McDonnell Douglas MD-80 Service 
Bulletin MD80-32-278, dated March 31, 1995: Within 36 months after 
February 26, 1996, modify the hydraulic damper assembly (by removing 
shims, increasing bolt torque, and incorporating changes to increase 
the volume of fluid passing between the two damper chambers) in 
accordance with McDonnell Douglas MD-80 Service Bulletin MD80-32-
278, dated March 31, 1995, or Revision 1, dated September 6, 1995.

Restatement of Requirements of AD 96-21-01

Replacement or Modification

    (c) For airplanes listed in McDonnell Douglas Service Bulletin 
DC9-32-289, dated March 7, 1996: Within 24 months after November 14, 
1996 (the effective date of AD 96-21-01, amendment 39-9777), either 
replace or modify the MLG hydraulic damper assembly, in accordance 
with the procedures specified as either ``Option 1'' or ``Option 
2,'' respectively, of the service bulletin.

New Requirements of this Ad

Replacement or Modification

    (d) For McDonnell Douglas Model DC-9 series airplanes, and C-9 
(military) series airplanes (as listed in McDonnell Douglas Alert 
Service Bulletin DC9-32A311, Revision 01): Within 18 months after 
the effective date of this AD, accomplish the requirements specified 
in either paragraph (d)(1) or (d)(2) of this AD in accordance with 
McDonnell Douglas Service Bulletin DC9-32-311, dated July 6, 1998, 
or McDonnell Douglas Alert Service Bulletin DC9-32A311, Revision 01, 
dated March 8, 1999.
    (1) Modify the left and right MLG hydraulic damper assemblies.
    (2) Replace the left and right MLG hydraulic damper assemblies 
with modified and reidentified hydraulic damper assemblies having 
part number (P/N) SR09320057-7005, SR09320057-7007, SR09320057-7009, 
or 5923142-5513.
    (e) For McDonnell Douglas Model DC-9-80 series airplanes, and 
MD-88 airplanes (as listed in McDonnell Douglas Alert Service 
Bulletin DC9-32A311, Revision 01): Within 3,000 flight cycles after 
incorporation of the latest configuration of the left and right MLG 
hydraulic damper assemblies, or within 9 months after the effective 
date of this AD, whichever occurs later; accomplish the requirements 
specified in either paragraph (d)(1) or (d)(2) of this AD in 
accordance with McDonnell Douglas Service Bulletin DC9-32-311, dated 
July 6, 1998, or McDonnell Douglas Alert Service Bulletin DC9-
32A311, Revision 01, dated March 8, 1999.
    (f) Paragraph (b) or (c) of this AD, as applicable, must be 
accomplished prior to or concurrent with the accomplishment of 
either paragraph (d) or (e) of this AD, as applicable.

Spares

    (g) As of the effective date of this AD, no person shall install 
on any airplane a damper sub assembly having P/N SR09320057-9, 
SR09320057-17, or 5923142-5017; or a damper assembly having P/N 
SR09320057-7001, SR09320057-7003, or 5923142-5511, unless the part 
has been modified and reidentified in accordance with paragraph 
(d)(2) of this AD.

Alternative Methods of Compliance

    (h) 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

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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.

Special Flight Permits

    (i) 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

    (j) The actions shall be done in accordance with McDonnell 
Douglas MD-80 Service Bulletin MD80-32-276, dated March 31, 1995; 
McDonnell Douglas MD-80 Service Bulletin MD80-32-276, Revision 1, 
dated October 17, 1995; McDonnell Douglas MD-80 Service Bulletin 
MD80-32-278, dated March 31, 1995; McDonnell Douglas MD-80 Service 
Bulletin MD80-32-278, Revision 1, dated September 6, 1995; McDonnell 
Douglas Service Bulletin DC9-32-289, dated March 7, 1996; McDonnell 
Douglas Service Bulletin DC9-32-311, dated July 6, 1998; or 
McDonnell Douglas Alert Service Bulletin DC9-32A311, Revision 1, 
dated March 8, 1999; as applicable.
    (1) The incorporation by reference of McDonnell Douglas Service 
Bulletin DC9-32-311, dated July 6, 1998; or McDonnell Douglas Alert 
Service Bulletin DC9-32A311, Revision 1, dated March 8, 1999; is 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51.
    (2) The incorporation by reference of McDonnell Douglas MD-80 
Service Bulletin MD80-32-276, dated March 31, 1995, McDonnell 
Douglas MD-80 Service Bulletin MD80-32-276, Revision 1, dated 
October 17, 1995; McDonnell Douglas MD-80 Service Bulletin MD80-32-
278, dated March 31, 1995; and McDonnell Douglas MD-80 Service 
Bulletin MD80-32-278, Revision 1, dated September 6, 1995; was 
approved previously by the Director of the Federal Register as of 
February 26, 1996 (61 FR 2407, January 26, 1996).
    (3) The incorporation by reference of McDonnell Douglas Service 
Bulletin DC9-32-289, dated March 7, 1996, was approved previously by 
the Director of the Federal Register as of November 14, 1996 (61 FR 
53042, October 10, 1996).
    (4) Copies may be obtained from Boeing Commercial Aircraft 
Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, 
California 90846. Copies may be inspected 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; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (k) This amendment becomes effective on November 12, 1999.

    Issued in Renton, Washington, on September 28, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-25766 Filed 10-6-99; 8:45 am]
BILLING CODE 4910-13-U