[Federal Register Volume 63, Number 2 (Monday, January 5, 1998)]
[Proposed Rules]
[Pages 174-176]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-124]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-105-AD]
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: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (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 requires an inspection to detect chafing 
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. That AD was prompted by 
reports of incidents in which the pneumatic sense pipe chafed against 
the FIREX supply pipe of the number one engine. This action would 
revise the applicability of the existing AD to include additional 
airplanes and remove others. The actions specified by the proposed AD 
are intended to prevent chafing of the FIREX supply pipe, which could 
result in a hole in the pipe and consequently 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 19, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-105-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: Robert Baitoo, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(562) 627-5245; 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 97-NM-105-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. 97-NM-105-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

[[Page 175]]

Discussion

    On June 9, 1995, the FAA issued AD 95-12-25, amendment 39-9278 (60 
FR 32579, June 23, 1995), applicable to certain McDonnell Douglas Model 
DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 
airplanes, to require an inspection to detect chafing 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. That action was prompted by reports of 
incidents in which the pneumatic sense pipe chafed against the FIREX 
supply pipe of the number one engine. The requirements of that AD are 
intended to prevent chafing of the FIREX supply pipe, which could 
result in a hole in the pipe and consequently prevent the proper 
distribution of the fire extinguishing agent within the nacelle in the 
event of a fire.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA has reviewed and approved 
McDonnell Douglas DC-9 Service Bulletin 26-25, dated May 25, 1994; 
McDonnell Douglas Service Bulletin DC9-26-025, Revision 03, dated July 
25, 1996; and McDonnell Douglas Service Bulletin DC9-26-025, Revision 
04, dated April 30, 1997. The inspection procedures described in the 
original version, Revision 03, and Revision 04 are identical to those 
described in Revision 1 and Revision 2 of the service bulletin (which 
were referenced in AD 95-12-25 as the appropriate sources of service 
information). Revision 04 of the service bulletin expands the 
effectivity listing to include additional airplanes that are subject to 
the addressed unsafe condition and removes other airplanes from the 
effectivity listing.

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 supersede AD 95-12-25 to continue to require an 
inspection to detect chafing 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. The proposed AD would revise the applicability of the 
existing AD to include additional airplanes and remove others. The 
actions would be required to be accomplished in accordance with the 
service bulletin described previously.

Cost Impact

    There are approximately 1,691 McDonnell Douglas 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 834 
airplanes of U.S. registry would be affected by this proposed AD.
    The actions that are currently required by AD 95-12-25, and 
retained in this proposed AD, take approximately 1 work hour per 
airplane to accomplish, at an average labor rate of $60 per work hour. 
The cost of required parts will be nominal. Based on these figures, the 
cost impact of the currently required actions on U.S. operators is 
estimated to be $50,040, or $60 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the current or proposed 
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 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 removing amendment 39-9278 (60 FR 
32579, June 23, 1995), and by adding a new airworthiness directive 
(AD), to read as follows:

McDonnell Douglas: Docket 97-NM-105-AD. Supersedes AD 95-12-25, 
Amendment 39-9278.

    Applicability: Model DC-9-30, -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 C-9 (military) 
series airplanes; as listed in McDonnell Douglas Service Bulletin 
DC9-26-025, Revision 04, dated April 30, 1997; 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 (b) 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 chafing of the FIREX supply pipe, which could result 
in a hole in the pipe and consequently 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, dated May 25, 1994; McDonnell Douglas DC-9 Service 
Bulletin 26-25, Revision 1, dated September 30, 1994; McDonnell 
Douglas DC-9 Service Bulletin 26-25, Revision 2, dated April 18, 
1995; McDonnell Douglas Service Bulletin DC9-26-025, Revision 03, 
dated July 25, 1996; or McDonnell Douglas Service Bulletin DC9-26-
025, Revision 04, dated April 30, 1997.
    (1) If any chafing is detected, prior to further flight, 
accomplish paragraphs (a)(1)(i)

[[Page 176]]

and (a)(1)(ii) 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 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.

    Issued in Renton, Washington, on December 29, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-124 Filed 1-2-98; 8:45 am]
BILLING CODE 4910-13-P