[Federal Register Volume 61, Number 177 (Wednesday, September 11, 1996)]
[Proposed Rules]
[Pages 47834-47835]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-23100]



[[Page 47834]]

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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-257-AD]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-7 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-7 
series airplanes. This proposal would require modification of the power 
control relay installation of the emergency lights. The proposed AD 
also would require revising the FAA-approved Airplane Flight Manual to 
include procedures for turning off and on the emergency lights switch 
in certain conditions. This proposal is prompted by a report that the 
emergency lights do not automatically illuminate when all generated 
electrical power on the airplane is lost and the power to the left 
essential bus is maintained from the aircraft batteries. The actions 
specified by the proposed AD are intended to ensure that the emergency 
lights illuminate when needed in an emergency situation.

DATES: Comments must be received by October 21, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-257-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.

FOR FURTHER INFORMATION CONTACT: Wing Chan, Aerospace Engineer, Systems 
and Flight Test Branch, ANE-172, FAA, New York Aircraft Certification 
Office, Engine and Propeller Directorate, 10 Fifth Street, Third Floor, 
Valley Stream, New York; 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 95-NM-257-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-103, Attention: Rules 
Docket No. 95-NM-257-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Transport Canada Aviation, which is the airworthiness authority for 
Canada, recently notified the FAA that an unsafe condition may exist on 
certain de Havilland Model DHC-7 series airplanes. Transport Canada 
Aviation advises that the emergency lights do not automatically 
illuminate when all generated electrical power on the airplane is lost 
and the power to the left essential bus is maintained from the aircraft 
batteries. This condition, if not corrected, could result in the 
failure of the emergency lights to illuminate when needed in an 
emergency situation.

Explanation of Relevant Service Information

    Bombardier has issued Service Bulletin S.B. 7-33-23, Revision `A', 
dated October 20, 1995 (Modification 7/2622), which describes 
procedures for modification of the power control relay installation of 
the emergency lights. The modification involves installation of a new 
relay assembly and connection of the wires to the terminal block. The 
modification will provide direct monitoring of each generator control 
unit, and upon loss of all DC generators, the emergency lights will be 
activated by the emergency light batteries. Transport Canada Aviation 
classified this service bulletin as mandatory and issued Canadian 
airworthiness directive CF-95-03, dated March 9, 1995, in order to 
assure the continued airworthiness of these airplanes in Canada.
    Bombardier also has issued Dash 7 Flight Manual PSM 1-71A-1A, 
Revision 39, dated August 22, 1994, which describes procedures for 
turning off the emergency lights switch following accomplishment of 
Modification 7/2622. The flight manual also describes procedures 
turning on the emergency lights switch, if the emergency lights are 
required.

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, Transport Canada Aviation has kept 
the FAA informed of the situation described above. The FAA has examined 
the findings of Transport Canada Aviation, 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, the 
proposed AD would require modification of the power control relay 
installation of the emergency lights. Following accomplishment of the 
proposed modification, the proposed AD also would require revising the 
Limitations Section of the FAA-approved Airplane Flight Manual to 
include procedures for turning off and on the emergency lights switch. 
The actions would be required to be accomplished in accordance with the 
service bulletin and flight manual described previously.

[[Page 47835]]

Cost Impact

    The FAA estimates that 47 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 4 work hours per airplane to accomplish 
the proposed modification, at an average labor rate of $60 per work 
hour. Required parts would cost approximately $2,713 per airplane. 
Based on these figures, the cost impact of the modification proposed by 
this AD on U.S. operators is estimated to be $138,791, or $2,953 per 
airplane.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed AFM revision, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the AFM revision 
proposed by this AD on U.S. operators is estimated to be $2,820, or $60 
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 Havilland, Inc.: Docket 95-NM-257-AD.

    Applicability: Model DHC-7 series airplanes, serial numbers 003 
through 113 inclusive, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 ensure that the emergency lights illuminate when needed in an 
emergency situation, accomplish the following:
    (a) Within 6 months after the effective date of this AD, modify 
the power control relay installation of the emergency lights, in 
accordance with de Havilland Service Bulletin S.B. 7-33-23, Revision 
`A', dated October 20, 1995.
    (b) Following accomplishment of paragraph (a) of this AD, revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) by inserting a copy of de Havilland Dash 7 Flight Manual PSM 
1-71A-1A, Revision 39, dated August 22, 1994, into the AFM.
    (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, 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.

    (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 September 4, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-23100 Filed 9-10-96; 8:45 am]
BILLING CODE 4910-13-U