[Federal Register Volume 59, Number 22 (Wednesday, February 2, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-2333]


[[Page Unknown]]

[Federal Register: February 2, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-203-AD]

 

Airworthiness Directives; de Havilland Model DHC-8-301 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-
301 airplanes. This proposal would require modification of the sidewall 
panels in the passenger cabin. This proposal is prompted by a report 
that inadequate venting between the cabin and the compartments beneath 
the floor could occur during rapid fuselage decompression. The actions 
specified by the proposed AD are intended to prevent collapse of the 
floor and subsequent injury to passengers.

DATES: Comments must be received by March 29, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 93-NM-203-AD, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9 a.m. and 3 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from de Havilland, Inc., 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, 181 South Franklin Avenue, room 202, Valley 
Stream, New York.

FOR FURTHER INFORMATION CONTACT: Jon Hjelm, Aerospace Engineer, 
Airframe Branch, ANE-172, FAA, Engine and Propeller Directorate, New 
York Aircraft Certification Office, 181 South Franklin Avenue, room 
202, Valley Stream, New York 11581; telephone (516) 791-6220; fax (516) 
791-9024.

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 93-NM-203-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. 93-NM-203-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-8-301 airplanes. Transport Canada 
Aviation advises that, during a post-certification review of the design 
for cabin venting between compartments, the manufacturer discovered 
that the cabin and the compartments beneath the floor could be 
inadequately vented during rapid fuselage decompression of these 
airplanes. This condition is the result of movement of the sidewall 
panels in the passenger cabin, which may partially block the vents 
along the bottom edges of the panels. This condition, if not corrected, 
could result in collapse of the floor and subsequent injury to 
passengers.
    De Havilland has issued Service Bulletin No. 8-25-53, dated August 
4, 1989, that describes procedures for modification of the sidewall 
panels in the passenger cabin (Modification No. 8/1339). The 
modification entails bonding spacers along the lower edge of the cabin 
sidewall panels to provide support. Installation of the spacers will 
ensure that intercompartmental venting is maintained in the event of 
rapid fuselage decompression. Transport Canada Aviation classified this 
service bulletin as mandatory and issued Canadian Airworthiness 
Directive No. CF-90-26, dated November 29, 1990, in order to assure the 
continued airworthiness of these airplanes in Canada.
    This airplane model is manufactured in Canada and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations 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.
    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 
sidewall panels in the passenger cabin. The actions would be required 
to be accomplished in accordance with the service bulletin described 
previously.
    The FAA estimates that 23 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 32 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $55 per work hour. Required parts would be 
provided by the manufacturer at no cost to operators. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $40,480, or $1,760 per airplane. This total cost figure 
assumes that no operator has yet accomplished the proposed requirements 
of this AD action.
    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 14 
CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

De Havilland, Inc: Docket 93-NM-203-AD.

    Applicability: Model DHC-8-301 airplanes; serial numbers 116 
through 185 inclusive, 187, and 188; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent collapse of the floor and subsequent injury to 
passengers, accomplish the following:
    (a) Within 6 months after the effective date of this AD, modify 
the sidewall panels in the passenger cabin (Modification No. 8/1339) 
in accordance with de Havilland Service Bulletin No. 8-25-53, dated 
August 4, 1989.
    (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), ANE-170, 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: 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 FAR 
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 January 27, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-2333 Filed 2-1-94; 8:45 am]
BILLING CODE 4910-13-M