[Federal Register Volume 63, Number 63 (Thursday, April 2, 1998)]
[Proposed Rules]
[Pages 16174-16175]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8709]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-14-AD]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-8-100, -200, and 
-300 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 de Havilland Model DHC-8-
100, -200, and -300 series airplanes. This proposal would require a 
one-time inspection to detect discrepancies in electrical wiring and 
wiring harness behind the lavatory, and corrective actions. This 
proposal is prompted by issuance of mandatory continuing airworthiness 
information by a foreign civil airworthiness authority. The actions 
specified by the proposed AD are intended to prevent chafing of 
electrical wiring, which could result in severe overheating of the 
wiring, consequent smoke in the flight deck and cabin, and possible 
injury to flightcrew or passengers.

DATES: Comments must be received by May 4, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-14-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 Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 
6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and 
Propeller Directorate, New York Aircraft Certification Office, 10 Fifth 
Street, Third Floor, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT: Wing Chan, Aerospace Engineer, Systems 
and Flight Test Branch, ANE-172, FAA, Engine and Propeller Directorate, 
New York Aircraft Certification Office, 10 Fifth Street, Third Floor, 
Valley Stream, New York 11581; telephone (516) 256-7511; fax (516) 568-
2716.

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 98-NM-14-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-14-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Transport Canada Aviation (TCA), which is the airworthiness 
authority for Canada, notified the FAA that an unsafe condition may 
exist on certain de Havilland Model DHC-8-100, -200, and -300 series 
airplanes. TCA advises that it has received reports of smoke in the 
flight deck and cabin, caused by severe overheating of chafed 
electrical wiring located at the top edge of the lavatory forward 
panel. Further investigation revealed that the chafing was caused by 
inadequate clearance between a wiring harness and the lavatory forward 
panel. Such chafing, if not corrected, could result in severe 
overheating of electrical wiring, consequent smoke in the flight deck 
and cabin, and possible injury to flightcrew or passengers.

Explanation of Relevant Service Information

    Bombardier has issued de Havilland Service Bulletin S.B. 8-24-50, 
dated April 25, 1997, which describes procedures for a one-time 
inspection to detect chafing of the electrical wiring or wiring 
harness, and to measure clearance between the wiring harness and the 
lavatory forward panel; repair of damaged wiring; and modification of 
the wiring harness and lavatory forward panel. The modification 
involves installing protective wrap on the wiring harness, and trimming 
the top outboard edge of the lavatory forward panel. Accomplishment of 
the actions specified in the service bulletin is intended to adequately 
address the identified unsafe condition. TCA classified this service 
bulletin as mandatory and issued Canadian airworthiness directive CF-
97-14, dated July 22, 1997, in order to assure the continued 
airworthiness of these airplanes in Canada.

[[Page 16175]]

FAA's Conclusions

    This airplane model is manufactured in Canada and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, TCA has kept the FAA informed of the 
situation described above. The FAA has examined the findings of TCA, 
reviewed all available information, and determined that AD action is 
necessary for products of this type design that are certificated for 
operation in the United States.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require accomplishment of 
the actions specified in the service bulletin described previously.

Cost Impact

    The FAA estimates that 163 airplanes of U.S. registry would be 
affected by this proposed AD. It would take approximately 1 work hour 
per airplane to accomplish the proposed inspection, at an average labor 
rate of $60 per work hour. Based on this figure, the cost impact of the 
inspection proposed by this AD on U.S. operators is estimated to be 
$9,780, or $60 per airplane.
    It would take approximately 20 work hours per airplane to 
accomplish the proposed modification, at an average labor rate of $60 
per work hour. Required parts would be provided by the manufacturer at 
no cost to operators. Based on these figures, the cost impact of the 
modification proposed by this AD on U.S. operators is estimated to be 
$195,600 or $1,200 per airplane.
    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:

    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:

De Haviland Inc.: Docket 98-NM-14-AD.

    Applicability: Model DHC-8-100, -200, and -300 series airplanes, 
serial numbers 003 through 433 inclusive, except 031, 408, and 413; 
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 electrical wiring, which could result in 
severe overheating of the wiring, consequent smoke in the flight 
deck and cabin, and possible injury to flightcrew or passengers, 
accomplish the following:
    (a) Within 9 months after the effective date of this AD, perform 
a one-time inspection to detect discrepancies in the electrical 
wiring or wiring harness located behind the lavatory, in accordance 
with Bombardier Service Bulletin S.B. 8-24-50, dated April 25, 1997.
    (1) If no discrepancy is found, prior to further flight, modify 
the wiring harness and the lavatory forward panel, in accordance 
with the service bulletin.
    (2) If any discrepancy is found, prior to further flight, repair 
it and modify the wiring harness and the lavatory forward panel, 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, New York Aircraft Certification 
Office (ACO), FAA, Engine and Propeller Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, New York ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York 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.

    Note 3: The subject of this AD is addressed in Canadian 
airworthiness directive CF-97-14, dated July 22, 1997.

    Issued in Renton, Washington, on March 27, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8709 Filed 4-1-98; 8:45 am]
BILLING CODE 4910-13-U