[Federal Register Volume 59, Number 235 (Thursday, December 8, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30141]


[[Page Unknown]]

[Federal Register: December 8, 1994]


-----------------------------------------------------------------------


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-181-AD]

 

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: Notice of proposed rulemaking (NPRM).
SUMMARY: This document proposes the adoption of 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 proposal would 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. This proposal 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 the proposed 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: Comments must be received by February 6, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-181-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 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. This information may be 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington.

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; telephone (310) 627-5245; fax (310) 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 94-NM-181-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-103, Attention: Rules 
Docket No. 94-NM-181-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports of incidents in which a 
pneumatic sense pipe chafed against the FIREX supply pipe of the number 
one engine on McDonnell Douglas Model DC-9 series airplanes. These 
pipes are located aft of the pressure bulkhead and inboard of longeron 
15 left. In one incident, a 0.2 inch (5 mm) hole was worn into the 
FIREX supply pipe. Investigation revealed that, due to vibration, the 
pneumatic pipe and/or FIREX pipe assembly can move from its original 
position during flight operations or landing. Chafing of the FIREX 
supply pipe assembly could eventually create a hole in the pipe. Such a 
hole, if not detected and corrected, could prevent the proper 
distribution of the fire extinguishing agent within the nacelle in the 
event of a fire.
    The FAA has reviewed and approved McDonnell Douglas DC-9 Service 
Bulletin 26-25, Revision 1, dated September 30, 1994, which describes 
procedures for inspection to detect chafing of 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. Accomplishment of the modification will 
reposition the clamp marriage to a more effective location and will 
provide adequate separation between the FIREX and pneumatic pipe 
assemblies.
    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 inspection to detect chafing on 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. The actions would be required to be 
accomplished in accordance with the service bulletin described 
previously.

    [Note: As a result of recent communications with the Air 
Transport Association (ATA) of America, the FAA has learned that, in 
general, some operators may misunderstand the legal effect of AD's 
on airplanes that are identified in the applicability provision of 
the AD, but that have been altered or repaired in the area addressed 
by the AD. Under these circumstances, at least one operator appears 
to have incorrectly assumed that its airplane was not subject to an 
AD. On the contrary, all airplanes identified in the applicability 
provision of an AD are legally subject to the AD. If an airplane has 
been altered or repaired in the affected area in such a way as to 
affect compliance with the AD, the owner or operator is required to 
obtain FAA approval for an alternative method of compliance with the 
AD, in accordance with the paragraph of each AD that provides for 
such approvals. A note has been included in this notice to clarify 
this requirement.]

    There are approximately 1,954 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 1,097 airplanes 
of U.S. registry would be affected by this proposed AD, that it would 
take approximately 1 work hour per airplane to accomplish the proposed 
actions, and that the average labor rate is $60 per work hour. The cost 
of required parts would be nominal. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$65,820, or $60 per airplane.
    The total cost impact figure discussed above is 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.
    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. 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:

McDonnell Douglas: 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 1, dated September 30, 
1994; 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) 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.
    (1) If any chafing is detected, prior to further flight, either 
replace the chafed pipe assemblies with new pipe assemblies and 
modify the FIREX and the pneumatic sense pipe assembly clamp 
marriage; or repair chafed pipe assemblies; in accordance with the 
service bulletin.
    (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.

    Issued in Renton, Washington, on December 2, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-30141 Filed 12-7-94; 8:45 am]
BILLING CODE 4910-13-U