[Federal Register Volume 64, Number 207 (Wednesday, October 27, 1999)]
[Proposed Rules]
[Pages 57823-57825]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-27947]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-173-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model MD-11 and MD-
11F 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
MD-11 and MD-11F series airplanes. This proposal would require
replacement of the existing terminal strips and supports above the main
cabin area; and installation of spacers between terminal strips and
mounting brackets in the avionics compartment; as applicable. This
proposal is prompted by a report indicating that, during flight, an
incident of electrical arcing occurred at a terminal strip located
overhead in the main cabin. The actions specified by the proposed AD
are intended to prevent electrical arcing caused by power feeder cable
terminal lugs grounding against terminal strip support brackets, which
could result in smoke and fire in the main cabin or avionics
compartment.
DATES: Comments must be received by December 13, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-173-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9 a.m. and 3 p.m., Monday through Friday, except
Federal holidays.
[[Page 57824]]
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 Avenue, SW., Renton, Washington; or at the FAA,
Transport Airplane Directorate, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137.
FOR FURTHER INFORMATION CONTACT: Brett Portwood, 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) 627-5350;
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-173-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-173-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
As part of its practice of re-examining all aspects of the service
experience of a particular aircraft whenever an accident occurs, the
FAA has become aware of an incident where arcing occurred during flight
at a terminal strip located overhead in the main cabin of a McDonnell
Douglas Model MD-11F series airplane. The arcing resulted in sparks
landing on a cargo cover, which consequently caught fire. Investigation
revealed that the design and installation did not provide adequate
clearance between the terminal strips and mounting brackets, which
allowed a power feeder cable terminal lug to ground against a terminal
strip support bracket. Investigations conducted of other similar
installations have revealed the potential for the same type of incident
to occur at other specific aircraft locations. This condition, if not
corrected, could result in smoke and fire in the main cabin or avionics
compartment.
The subject area on certain McDonnell Douglas Model MD-11 series
airplanes is identical to that on the affected Model MD-11F series
airplanes. Therefore, both of these models may be subject to the same
unsafe condition.
The incident described previously is not considered to be related
to an accident that occurred off the coast of Nova Scotia involving a
McDonnell Douglas Model MD-11 series airplane. The cause of that
accident is still under investigation.
Other Related Rulemaking
The FAA, in conjunction with Boeing and operators of Model MD-11
series airplanes, is continuing to review all aspects of the service
history of those airplanes to identify potential unsafe conditions and
to take appropriate corrective actions. This proposed airworthiness
directive (AD) is one of a series of actions identified during that
process. The process is continuing and the FAA may consider additional
rulemaking actions as further results of the review become available.
Explanation of Relevant Service Information
The FAA has reviewed and approved McDonnell Douglas Alert Service
Bulletin MD11-24A150, dated March 25, 1999, which describes procedures
for replacement of the existing terminal strips and supports above the
main cabin at station Y=5-32.000 with new terminal strips and supports.
The FAA also has reviewed and approved McDonnell Douglas Alert Service
Bulletin MD11-24A147, dated March 24, 1999, which describes procedures
for installation of spacers between terminal strips and mounting
brackets in the avionics compartment. 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 applicable service bulletin described previously.
Cost Impact
There are approximately 136 airplanes listed in McDonnell Douglas
Alert Service Bulletin MD11-24A147, dated March 24, 1999, in the
worldwide fleet. The FAA estimates that 40 airplanes of U.S. registry
would be affected by this proposed action, that would take
approximately 3 work hours per airplane to accomplish the proposed
installation, and that the average labor rate is $60 per work hour.
Required parts would cost approximately $445 per airplane. Based on
these figures, the cost impact of the installation proposed by this AD
on U.S. operators is estimated to be $25,000, or $625 per airplane.
The 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. However, the FAA has been
advised that manufacturer warranty remedies are available for some
labor with accomplishing the proposed actions. Therefore, the future
economic cost impact of this rule on U.S. operators may be less than
the cost impact figures indicated above.
There are approximately 14 airplanes listed in McDonnell Douglas
Alert Service Bulletin MD11-24A150, dated March 25, 1999, in the
worldwide fleet. Currently, none of these airplanes are on the US
Register. However, should an affected airplane be imported and placed
on the US Register in the future, it would require approximately 1 work
hour to accomplish the proposed modification, at an average labor rate
of $60 per work hour. The cost of required parts would be $885 per
airplane. Based
[[Page 57825]]
on these figures, the cost impact of this modification proposed by this
AD would be $945 per airplane.
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 adding the following new
airworthiness directive:
McDonnell Douglas: Docket 99-NM-173-AD.
Applicability: Model MD-11 and MD-11F series airplanes, as
listed in McDonnell Douglas Alert Service Bulletin MD11-24A150,
dated March 25, 1999, and McDonnell Douglas Alert Service Bulletin
MD11-24A147, dated March 24, 1999; 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 electrical arcing caused by power feeder
cable terminal lugs grounding against terminal strip support
brackets, which could result in smoke and fire in the main cabin or
avionics compartment, accomplish the following:
Replacement of Terminal Strips and Supports
(a) For airplanes listed in the effectivity of McDonnell Douglas
Alert Service Bulletin MD11-24A150, dated March 25, 1999, on which
the modification specified in McDonnell Douglas Service Bulletin
MD11-24-085, dated August 1, 1995, has not been accomplished: Within
1 year after the effective date of this AD, replace the existing
terminal strips and supports above the main cabin at station Y=5-
32.000 with new terminal strips and supports in accordance with
McDonnell Douglas Alert Service Bulletin MD11-24A150, dated March
25, 1999.
Installation of Spacers
(b) For airplanes listed in the effectivity of McDonnell Douglas
Alert Service Bulletin MD11-24A147, dated March 24, 1999: Within 6
months after the effective date of this AD, install spacers between
terminal strips and mounting brackets in the avionics compartment in
accordance with the service bulletin.
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
Secs. 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 October 20, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-27947 Filed 10-26-99; 8:45 am]
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