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[Federal Register Volume 63, Number 147 (Friday, July 31, 1998)]
[Proposed Rules]
[Pages 40852-40854]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20436]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-172-AD]
RIN 2120-AA64

Airworthiness Directives; de Havilland Model DHC-8-102, -103, -
106, -201, -202, -301, -311, and -315 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-
102, -103, -106, -201, -202, -301, -311, and -315 series airplanes. 
This proposal would require a one-time inspection to detect chafing of 
electrical wires in the cable trough below the cabin floor; repair, if 
necessary; installation of additional tie-mounts and tie-wraps; and 
application of sealant to rivet heads. 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 wires, which could result 
in an uncommanded shutdown of an engine during flight.

DATES: Comments must be received by August 31, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-172-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., Bombardier Regional Aircraft Division, 
Garratt Boulevard, Downsview, Ontario M3K 1Y5, 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: Peter Cuneo, Senior Aerospace 
Engineer, Systems and Flight Test

[[Page 40853]]

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) 256-7506; 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-172-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-172-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-8-102, -103, -106, -201, -202, 
-301, -311, and -315 series airplanes. TCA advises that a Model DHC-8 
series airplane experienced an uncommanded shutdown of an engine during 
flight, due to a short circuit between adjacent electrical wires in a 
cable trough below the cabin floor. The short circuit resulted in a 28-
volt signal being applied to the fuel shut-off valve, which stopped the 
flow of fuel to the engine. Investigation revealed that the short 
circuit was caused by chafing of electrical wires on the sharp edges of 
the rivets in the cable trough. This condition, if not corrected, could 
result in an uncommanded shutdown of an engine during flight.

Explanation of Relevant Service Information

    Bombardier has issued de Havilland Service Bulletin 8-53-66, dated 
March 27, 1998, which describes procedures for a one-time visual 
inspection to detect chafing of electrical wires in the cable trough 
below the cabin floor; repair, if necessary; installation of additional 
tie-mounts and tie-wraps; and application of sealant to rivet heads. 
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-98-08, dated March 26, 1998, in order to 
assure the continued airworthiness of these airplanes in Canada.

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 225 airplanes of U.S. registry would be 
affected by this proposed AD.
    For the 210 Model DHC-8-102, -103, -106, -201, and -202 series 
airplanes affected, it would take approximately 70 work hours per 
airplane to accomplish the proposed actions, at an average labor rate 
of $60 per work hour. Required parts would be provided by the 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of the proposed AD for these airplanes on U.S. operators is 
estimated to be 882,000, or $4,200 per airplane.
    For the 15 Model DHC-8-301, -311, and -315 series airplanes 
affected, it would take approximately 100 work hours per airplane to 
accomplish the proposed actions, at an average labor rate of $60 per 
work hour. Required parts would be provided by the manufacturer at no 
cost to the operators. Based on these figures, the cost impact of the 
proposed AD for these airplanes on U.S. operators is estimated to be 
$90,000, or $6,000 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

[[Page 40854]]

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 Havilland Inc.: Docket 98-NM-172-AD.

    Applicability: Model DHC-8-102, -103, -106, -201, -202, -301, -
311, and -315 series airplanes; serial numbers 3 through 519 
inclusive, excluding serial number 462; 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 wires, which could result in an 
uncommanded shutdown of an engine during flight, accomplish the 
following:
    (a) Within 36 months after the effective date of this AD, 
perform a one-time visual inspection to detect chafing of electrical 
wires in the cable trough below the cabin floor; install additional 
tie-mounts and tie-wraps; and apply sealant to rivet heads 
(reference de Havilland Modification 8/2705); in accordance with de 
Havilland Service Bulletin 8-53-66, dated March 27, 1998. If any 
chafing is detected during the inspection required by this 
paragraph, prior to further flight, repair 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-98-08, dated March 26, 1998.

    Issued in Renton, Washington, on July 24, 1998.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-20436 Filed 7-30-98; 8:45 am]
BILLING CODE 4910-13-U
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