[Federal Register Volume 66, Number 31 (Wednesday, February 14, 2001)]
[Proposed Rules]
[Pages 10232-10234]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-3677]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-347-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier 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 Bombardier Model DHC-8-
100, -200, and -300 series airplanes. This proposal would require 
removing certain foam filters from the cabin ducting installation 
located below the dado panels on the left- and right-hand sides of the 
airplane. This action is necessary to prevent an increased risk of 
spreading a fire or failure of the cabin to pressurize adequately if 
certain foam filters are installed. This action is intended to address 
the identified unsafe condition.

DATES: Comments must be received by March 16, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-347-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
<a href="/cdn-cgi/l/email-protection#566f7b37383b7b3826243b35393b3b3338221630373778313920"><span class="__cf_email__" data-cfemail="a49d89c5cac989cad4d6c9c7cbc9c9c1cad0e4c2c5c58ac3cbd2">[email protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-347-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.

[[Page 10233]]

    The service information referenced in the proposed rule may be 
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 
123 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, New York 
Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley 
Stream, New York.

FOR FURTHER INFORMATION CONTACT: Dan Parrillo, Aerospace Engineer, 
Systems and Flight Test Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New 
York 11581; telephone (516) 256-7505; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
    <bullet> Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    <bullet> For each issue, state what specific change to the proposed 
AD is being requested.
    <bullet> Include justification (e.g., reasons or data) for each 
request.
    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 2000-NM-347-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. 2000-NM-347-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the airworthiness 
authority for Canada, notified the FAA that an unsafe condition may 
exist on certain Bombardier Model DHC-8-100, -200, and -300 series 
airplanes. TCCA advises that certain foam filters for the cabin exhaust 
system were incorporated erroneously on production airplanes. (There is 
no requirement that these filters be installed.) These filters failed 
to pass the flammability tests specified in Appendix F of part 25 of 
the Federal Aviation Regulations (14 CFR part 25). This condition, if 
not corrected, could increase the risk of spreading a fire on the 
airplane.
    In addition, pressurization tests are required by Sec. 25.843(b) of 
the Federal Aviation Regulations [14 CFR 25.843(b)]; however, these 
tests were conducted without foam filters installed in the cabin 
exhaust system of the airplane. The impact on pressurization of the 
airplane to proper levels is unknown for airplanes on which these 
filters are installed; therefore, pressurization tests would have to be 
reaccomplished on any airplane having the filters. Installation of 
these filters could result in failure of the cabin to pressurize 
adequately.

Explanation of Relevant Service Information

    The manufacturer has issued Bombardier Repair Drawing RD8-21-23, 
Issue 2, dated December 16, 1999, which describes procedures for 
removing certain foam filters from the cabin ducting installation 
located below the dado panels on the left- and right-hand sides of the 
airplane. These procedures include: verifying that certain foam filters 
are installed behind the grille assemblies, inspecting the grille 
assemblies on both the port and starboard sides and along the entire 
length of the interior of the airplane, removing all foam filters and 
ensuring that no pieces remain, and reinstalling the grille assemblies 
by locating the fasteners and pressing each with a quarter-turn. 
Accomplishment of the actions specified in the repair drawing is 
intended to adequately address the identified unsafe condition. TCCA 
classified this repair drawing as mandatory and issued Canadian 
airworthiness directive CF-2000-25, dated August 28, 2000, in order to 
assure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

    These airplane models are manufactured in Canada and are type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the 
applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, TCCA has kept the FAA informed of 
the situation described above. The FAA has examined the findings of 
TCCA, 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 repair drawing described previously.

Cost Impact

    The FAA estimates that 38 Bombardier 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 8 work hours per airplane 
to accomplish the proposed actions, and that the average labor rate is 
$60 per work hour. Based on these figures, the cost impact of the 
proposed AD on U.S. operators is estimated to be $18,240, or $480 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. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect on the States, on the relationship between the national 
Government and

[[Page 10234]]

the States, or on the distribution of power and responsibilities among 
the various levels of government. Therefore, it is determined that this 
proposal would not have federalism implications under Executive Order 
13132.
    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:

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 2000-NM-347-
AD.

    Applicability: Model DHC-8-100, -200, and -300 series airplanes, 
certificated in any category, having serial numbers 408, 413, 434 
through 463 inclusive, 465 through 489 inclusive, 491 through 505 
inclusive, and 507.

    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 an increased risk of spreading a fire, or failure of 
the cabin to pressurize adequately if certain foam filters are 
installed, accomplish the following:

Removal of Foam Filters

    (a) Within 4 months after the effective date of this AD, remove 
the foam filters from the cabin ducting installation located below 
the dado panels on the left- and right-hand sides of the airplane 
(including verifying that the foam filters are installed behind the 
grille assemblies, inspecting the grille assemblies on both the port 
and starboard sides and along the entire length of the interior of 
the airplane, removing all foam filters and ensuring that no pieces 
remain, and reinstalling the grille assemblies by locating the 
fasteners and pressing each with a quarter-turn), per Bombardier 
Aerospace Repair Drawing RD8-21-23, Issue 2, dated December 16, 
1999.

Alternative Methods of Compliance

    (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. 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.

Special Flight Permits

    (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-2000-25, dated August 28, 2000.



    Issued in Renton, Washington, on February 7, 2001.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-3677 Filed 2-13-01; 8:45 am]
BILLING CODE 4910-13-U


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