[Federal Register Volume 62, Number 133 (Friday, July 11, 1997)]
[Proposed Rules]
[Pages 37170-37172]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-18151]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-04-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 
modification of the flight compartment door. This proposal is prompted 
by a report that the door lock mechanism of the flight compartment door 
jammed and it could not be opened using the alternate release 
mechanism. The actions specified by the proposed AD are intended to 
prevent failure of the alternate release mechanism of the flight 
compartment door, which could delay or impede the evacuation of the 
flightcrew during an emergency. Such failure also could result in the 
flightcrew not being able to assist passengers in the event of an 
emergency.

DATES: Comments must be received by August 18, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-04-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 11581.

FOR FURTHER INFORMATION CONTACT: Danko Kramar, Aerospace Engineer, 
Systems and Equipment Branch, ANE-

[[Page 37171]]

172, FAA, New York Aircraft Certification Office, Engine and Propeller 
Directorate, 10 Fifth Street, Third Floor, Valley Stream, New York 
11581; telephone (516) 256-7509; 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 97-NM-04-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. 97-NM-04-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-8-100, -200, and -300 series airplanes. 
Transport Canada Aviation advises it has received a report indicating 
that the door lock mechanism of the flight compartment door jammed and 
it could not be opened using the alternate release mechanism. 
Subsequent testing revealed that the flight compartment door could be 
opened, but more than reasonable force was required to pivot and open 
it into the passenger compartment. Such force damaged the flight 
compartment door and its surrounding structure. Failure of the 
alternate release method of the flight compartment door when the door 
becomes jammed could delay or impede the evacuation of the flightcrew 
during an emergency. Such failure also could result in the flightcrew 
not being able to assist passengers in the event of an emergency.

Explanation of Relevant Service Information

    Bombardier has issued Service Bulletin S.B. 8-52-39, Revision `A,' 
dated October 31, 1996, which describes procedures for modification of 
the flight compartment door. The modification involves reworking the 
flight compartment door and its surrounding structure, drilling a new 
hole in the bottom of the hinge half, installing the reworked hinge 
half, and replacing hinges. Accomplishment of this modification ensures 
proper operation of the alternate release mechanism of the flight 
compartment door. Transport Canada Aviation classified this service 
bulletin as mandatory and issued Canadian airworthiness directive CF-
96-20 R1, dated January 15, 1997, 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, 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 registered 
in the United States, the proposed AD would require modification of the 
flight compartment door. The actions would be required to be 
accomplished in accordance with the service bulletin described 
previously.

Cost Impact

    The FAA estimates that 133 de Havilland Model DHC-8-100, -200, and 
-300 series airplanes of U.S. registry would be affected by this 
proposed AD, that it would take approximately 4 work hours per airplane 
to accomplish the proposed actions, and that the average labor rate is 
$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 
proposed AD on U.S. operators is estimated to be $31,920, or $240 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:

[[Page 37172]]

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 97-NM-04-AD.

    Applicability: Model DHC-8-100, -200, and -300 series airplanes 
having serial numbers 3 through 433 inclusive, excluding serial 
numbers 269, 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 
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 (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 failure of the alternate release mechanism of the 
flight compartment door, which could delay or impede the evacuation 
of the flightcrew during an emergency, accomplish the following:
    (a) Within 9 months after the effective date of this AD, modify 
the flight compartment door (Modification 8/2337) in accordance with 
Bombardier Service Bulletin S.B. 8-52-39, Revision `A,' dated 
October 31, 1996.

    Note 2: Modification of the flight compartment door accomplished 
prior to the effective date of this AD, in accordance with 
Bombardier Service Bulletin S.B. 8-52-39, dated August 30, 1996, is 
considered acceptable for compliance with the modification required 
by paragraph (a) of this AD.

    (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 3: 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.

    Issued in Renton, Washington, on July 3, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-18151 Filed 7-10-97; 8:45 am]
BILLING CODE 4910-13-P