[Federal Register Volume 60, Number 121 (Friday, June 23, 1995)]
[Rules and Regulations]
[Pages 32579-32581]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-14630]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-181-AD; Amendment 39-9278; AD 95-12-25]


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 adopts 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 amendment 
requires an inspection to detect chafing [[Page 32580]] on the FIREX 
pipe assembly of the number one engine; and either repair of chafed 
pipe assemblies or replacement of the chafed pipe assemblies with new 
pipe assemblies; and modification of the FIREX and the pneumatic sense 
pipe assembly clamp marriage. This amendment is prompted by reports of 
incidents in which the pneumatic sense pipe chafed against the FIREX 
supply pipe of the number one engine. The actions specified by this AD 
are intended to prevent the chafing of the FIREX supply pipe, which 
could result in a hole in the pipe and subsequently prevent the proper 
distribution of the fire extinguishing agent within the nacelle in the 
event of a fire.

DATES: Effective July 24, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 24, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from McDonnell Douglas Corporation, 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: Robert Baitoo, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (310) 627-5245; fax (310) 
627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an 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 was published in the Federal Register on December 8, 1994 (59 
FR 63275). That action proposed to require inspection to detect chafing 
on the FIREX pipe assembly of the number one engine; and either 
replacement of the chafed pipe assemblies with new pipe assemblies and 
modification of the FIREX and the pneumatic sense pipe assembly clamp 
marriage, or repair of the chafed pipe assemblies.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposed rule.
    Two commenters request that the compliance time for accomplishment 
of the inspection be extended from the proposed 8 months to 12 months. 
This will allow the inspection to be accomplished during the time of a 
regularly scheduled ``C'' check. One commenter considers that adoption 
of the proposed compliance time of 8 months would result in an 
additional expense to operators to schedule special times for the 
accomplishment of this inspection. The FAA does not concur with the 
commenters' request to extend the compliance time for the inspection 
requirements. In developing an appropriate compliance time for this 
action, the FAA considered the safety implications, parts availability, 
and normal maintenance schedules for timely accomplishment of the 
inspection. In consideration of these items, as well as the several 
reports of chafing of the FIREX supply pipe assembly found on in-
service airplanes, the FAA has determined that 8 months represents the 
maximum interval of time allowable wherein the inspection can 
reasonably be accomplished and an acceptable level of safety can be 
maintained. However, paragraph (b) of the final rule does provide 
affected operators the opportunity to apply for an adjustment of the 
compliance time if data are presented to justify such an adjustment.
    One commenter states that paragraph (a)(1) of the proposed rule 
seems to offer an option of not modifying the clamping configuration if 
repair is needed. The commenter requests that paragraph (a)(1) be 
changed to read, ``* * * either replace the chafed pipe assemblies with 
new pipe assemblies or repair chafed pipe assemblies; and modify the 
FIREX * * *'' for clarification purposes. The FAA concurs. Further 
review of McDonnell Douglas Service Bulletin 26-25, which is referenced 
in the final rule as the appropriate source of service information, 
indicates that the repair procedures [described in paragraph 2.C.(2) of 
the service bulletin] include modification of the clamping 
configuration. Therefore, the modification is part of the repair, and 
is not optional. The FAA has revised paragraph (a)(1) of the final rule 
to clarify this modification requirement accordingly. Since this 
revision just clarifies a requirement of the rule, the FAA finds that 
it does not pose an increased burden on any operator.
    One commenter requests that Model DC-9 series airplanes that are 
not equipped with a ventral stair be excluded from the applicability of 
the proposed rule. The commenter states that these airplanes do not 
have a pipe assembly having part number P/N 7914299-521 or 7914299-524; 
these pipe assemblies are referenced in Revision 1 of the service 
bulletin that is cited in the proposal as the appropriate source of 
service information. The FAA concurs. Since issuance of the proposal, 
the FAA has reviewed and approved Revision 2 of McDonnell Douglas DC-9 
Service Bulletin 26-25, dated April 18, 1995. The procedures described 
in Revision 2 are identical to those described in Revision 1 , but 
include minor editorial changes. However, Revision 2 revises the 
effectivity listing of the service bulletin by removing 544 non-ventral 
stair Model DC-9 series airplanes. Accordingly, the applicability of 
the final rule has been revised to include only those airplanes listed 
in Revision 2 of the service bulletin. Additionally, the economic 
impact information, below, has been revised to reduce the total cost 
impact by the amount of costs applicable to the 544 airplanes that have 
been deleted from the applicability of the final rule. Further, the 
final rule has been revised to reference Revision 2 of the service 
bulletin as an additional source of service information.
    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.
    There are approximately 1,410 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 553 airplanes of 
U.S. registry will be affected by this AD, that it will take 
approximately 1 work hour per airplane to accomplish the required 
actions, and that the average labor rate is $60 per work hour. The cost 
of required parts will be nominal. Based on these figures, the total 
cost impact of the AD on U.S. operators is estimated to be $33,180, or 
$60 per airplane.
    The total 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 32581]] those actions in the future if this AD were not adopted.
    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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

95-12-25  McDonnell Douglas: Amendment 39-9278. Docket 94-NM-181-AD.

    Applicability: Model DC-9-10, -20, -30, -40, and -50 series 
airplanes; Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), 
and DC-9-87 (MD-87) series airplanes; Model MD-88 airplanes; and 
Model C-9 (Military) series airplanes; as listed in McDonnell 
Douglas DC-9 Service Bulletin 26-25, Revision 2, dated April 18, 
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 use the authority 
provided in paragraph (b) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the chafing of a hole in the FIREX supply pipe of the 
number one engine, which could prevent the proper distribution of 
the fire extinguishing agent within the nacelle in the event of a 
fire, accomplish the following:
    (a) Within 8 months after the effective date of this AD, perform 
an inspection to detect chafing of the FIREX pipe assembly of the 
number one engine, in accordance with McDonnell Douglas DC-9 Service 
Bulletin 26-25, Revision 1, dated September 30, 1994, or Revision 2, 
dated April 18, 1995.
    (1) If any chafing is detected, prior to further flight, 
accomplish paragraph (a)(1) and (a)(2) of this AD in accordance with 
the service bulletin. Where there are differences between the 
requirements of this AD and the procedures specified in the service 
bulletin, the AD prevails.
    (i) Either repair chafed pipe assemblies or replace the chafed 
pipe assemblies with new or serviceable pipe assemblies. And
    (ii) Modify the FIREX and the pneumatic sense pipe assembly 
clamp marriage.
    (2) If no chafing is detected, prior to further flight, modify 
the FIREX and the pneumatic sense pipe assembly clamp marriage in 
accordance with the service bulletin.
    (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 2: 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.
    (d) The inspection, replacement, modification, and repair shall 
be done in accordance with McDonnell Douglas DC-9 Service Bulletin 
26-25, Revision 1, dated September 30, 1994, or McDonnell Douglas 
DC-9 Service Bulletin 26-25, Revision 2, dated April 18, 1995. 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 McDonnell Douglas Corporation, P.O. 
Box 1771, Long Beach, California 90801-1771, Attention: Business 
Unit Manager, Technical Administrative Support, Dept. L51, M.C. 2-
98. 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.
    (e) This amendment becomes effective on July 24, 1995.

    Issued in Renton, Washington, on June 9, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-14630 Filed 6-22-95; 8:45 am]
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