[Federal Register Volume 63, Number 102 (Thursday, May 28, 1998)]
[Proposed Rules]
[Pages 29155-29157]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-14039]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-136-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model MD-90-30 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-90-30 series airplanes. This proposal would require modification of
the wiring of the strake ice protection system (SIPS). This proposal is
prompted by a report of a fire in the electrical and electronic
compartment of a Model MD-90-30 series airplane. The actions specified
by the proposed AD are intended to prevent an electrical short circuit
of the wiring of the SIPS, which could result in a fire in the
electrical and electronic compartment of the airplane.
DATES: Comments must be received by July 13, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-136-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: George Y. Mabuni, 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) 627-5341;
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
[[Page 29156]]
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 98-NM-136-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. 98-NM-136-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA received a report of a fire in the electrical and
electronic compartment of a Model MD-90-30 series airplane which
resulted in injury to a mechanic. Investigation revealed that the fire
was caused by an electrical short circuit at the termination of a wire
shield near the connector of the strake controller. The short circuit
has been attributed to damaged insulation of certain wiring of the
strake ice protection system (SIPS). This wiring insulation was damaged
during manufacture because a shield termination was not being performed
correctly. For this reason, this same condition may exist on other
airplanes of the same type. Damaged insulation of the wiring of the
SIPS could fail, which could cause an electrical short circuit between
the exposed wire conductors and the shielded ground. Such an electrical
short circuit of the wiring of the SIPS, if not corrected, could result
in a fire in the electrical and electronic compartment of the airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved McDonnell Douglas Alert Service
Bulletin MD90-30A021, dated March 31, 1998, which describes procedures
for modification of the wiring of the SIPS at the connectors of the
strakes and the strake controller. The modification involves removing
the pigtail ground wires at the connectors of the strakes and the
strake controller, installing shrink tubing over each power wire, and
performing a resistance test of the electrical insulation. (The alert
service bulletin refers to this resistance test as a ``resistance
check.'') If any strake heating wiring fails the resistance test, the
discrepant wiring is to be replaced with new wiring and retested.
Accomplishment of the actions specified in the alert service
bulletin 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 modification of the wiring of the strake ice
protection system. The actions would be required to be accomplished in
accordance with the alert service bulletin described previously.
Cost Impact
There are approximately 66 Model MD-90-30 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 23
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 15 work hours per airplane to accomplish
the proposed actions, and that the average labor rate is $60 per work
hour. The cost of the required parts would be minimal. Based on these
figures, the cost impact of the proposed AD on U.S. operators is
estimated to be $20,700, or $900 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.
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 98-NM-136-AD.
Applicability: Model MD-90-30 series airplanes, as listed in
McDonnell Douglas Alert Service Bulletin MD90-30A021, dated March
31, 1998; 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 an electrical short circuit of the wiring of the
strake ice protection system (SIPS), which could result in a fire in
the electrical and electronic compartment of the airplane,
accomplish the following:
(a) Within 180 days after the effective date of this AD, modify
the wiring of the SIPS and perform a resistance test of the
electrical insulation in accordance with McDonnell Douglas Alert
Service Bulletin MD90-30A021, dated March 31, 1998. If any strake
heating wiring fails the resistance test, prior to further flight,
replace the discrepant wiring with new wiring, and repeat the
resistance test, in accordance with the alert 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),
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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
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 May 20, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-14039 Filed 5-27-98; 8:45 am]
BILLING CODE 4910-13-P
