[Federal Register Volume 64, Number 167 (Monday, August 30, 1999)]
[Proposed Rules]
[Pages 47149-47151]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22395]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-90-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9 and C-9
(Military) Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain McDonnell Douglas Model
DC-9 and C-9 (military) series airplanes. This proposal would require
modification of the electrical power center and modification and
overhaul of certain alternating current power relays. This proposal is
prompted by reports indicating that the alternating current (AC) cross-
tie relay shorted out internally, which caused severe smoke and burn
damage to the relay, aircraft wiring, and adjacent panels. The actions
specified by the proposed AD are intended to prevent a short in the
cross-tie relay, which may result in in-flight electrical fires.
DATES: Comments must be received by October 14, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-90-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 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 FAA, Transport Airplane
Directorate, 1601 Lind
[[Page 47150]]
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: Elvin Wheeler, 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) 627-5344;
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 99-NM-90-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. 99-NM-90-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports indicating that the alternating
current cross-tie relay shorted out internally on McDonnell Douglas
Model DC-9 series airplanes, which caused severe smoke and burn damage
to the relay, aircraft wiring, and adjacent panels. Investigation
revealed that the electrical fire originated within the cross-tie relay
of the power distribution system. The cause of this incident has been
attributed to a phase-to-phase short within the relay. This condition,
if not corrected, could result in in-flight electrical fires.
Explanation of Relevant Service Information
The FAA has reviewed and approved McDonnell Douglas DC-9 Service
Bulletin 24-57, Revision 1, dated March 12, 1980, as amended by Change
Notification 24-57 R1 CN2, dated June 24, 1988, which describes
procedures for modification of the electrical power center. The
modification of the electrical power center involves installation of
two terminal boards, two nameplates, fourteen clamps, six current
limiters, a mount assembly, two zees near the alternating current cross
tie relay, and three spare alternating current cross tie relay current
limiters and nameplate.
The FAA also has reviewed Westinghouse Aerospace Service Bulletin
75-703, dated June 1977, which describes procedures for modification
and overhaul of certain alternating current power relays. The
modification of certain alternating current power relays involves
removal of part number 914F567-3 and installation of a -4
configuration.
The FAA also has reviewed McDonnell Douglas DC-9 Service Bulletin
DC9-24-156, dated March 31, 1995, which describes procedures for
replacement of the relays, P/N 914F567-3 or -4, with improved relays,
P/N 9008D09.
Accomplishment of the actions specified in the service bulletins is
intended to adequately address the identified unsafe condition.
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 require accomplishment of the actions specified in
the service bulletins described previously.
Cost Impact
There are approximately 924 McDonnell Douglas DC-9 and C-9
(military) series airplanes of the affected design in the worldwide
fleet. The FAA estimates that 392 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 7 work
hours per airplane (for Group I, 316 airplanes), and 3 work hours per
airplane (for Group II, 76 airplanes), to accomplish the proposed
actions, and that the average labor rate is $60 per work hour. Required
parts would cost approximately $490 per airplane. Based on these
figures, the cost impact of the proposed AD on U.S. operators is
estimated to be $287,560, or $910 per airplane (for Group I airplanes),
and $50,920, or $670 per airplane (for Group II airplanes), per
modification.
The cost impact figures discussed above are 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.
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:
[[Page 47151]]
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
McDonnell Douglas: Docket 99-NM-90-AD.
Applicability: Model DC-9 and C-9 (military) series airplanes,
as listed in McDonnell Douglas DC-9 Service Bulletin 24-57, Revision
1, dated March 12, 1980; 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 (c) 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 a short in the cross-tie relay, which may result in
in-flight electrical fires, accomplish the following:
Modification
(a) Within 12 months after the effective date of this AD, modify
the electrical power center in accordance with McDonnell Douglas DC-
9 Service Bulletin 24-57, Revision 1, dated March 12, 1980, as
amended by Change Notification 24-57 R1 CN2, dated June 24, 1988,
and accomplish the requirements specified in paragraph (a)(1) or
(a)(2) of this AD.
(1) Modify the Westinghouse alternating current power relays,
part number (P/N) 914F567-3 (i.e., cross-tie relays, generator
relays, auxiliary power relays, and external power relays), to a -4
configuration, in accordance with Westinghouse Aerospace Service
Bulletin 75-703, dated June 1977.
(2) Replace the Westinghouse alternating current power relays,
P/N 914F567-3 or -4 with improved relays, P/N 9008D09, in accordance
with McDonnell Douglas DC-9 Service Bulletin DC9-24-156, dated March
31, 1995.
Overhaul
(b) Overhaul the Westinghouse alternating current power relays,
in accordance with Westinghouse service bulletin 75-703, dated June
1977, at times specified in paragraph (b)(1) or (b)(2) of this AD,
as applicable.
(1) For airplanes equipped with Westinghouse relay, P/N 914F567-
4, within 7,000 flight hours after accomplishing the modification
required by paragraph (a) of this AD, overhaul the relay and repeat
the overhaul at intervals not to exceed 7,000 flight hours.
(2) For airplanes equipped with Westinghouse relay, P/N 9008D09,
within 12,000 flight hours after accomplishing the modification
required by paragraph (a) of this AD, overhaul the relay and repeat
the overhaul at intervals not to exceed 12,000 flight hours.
Alternative Methods of Compliance
(c) 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.
Special Flight Permits
(d) 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 August 23, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-22395 Filed 8-27-99; 8:45 am]
BILLING CODE 4910-13-P
