[Federal Register Volume 69, Number 97 (Wednesday, May 19, 2004)]
[Proposed Rules]
[Pages 28863-28865]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-11290]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-285-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-101, -102, -103, 
-106, -201, -202, -301, -311, and -315 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Bombardier Model DHC-8-
101, -102, -103, -106, -201, -202, -301, -311, and -315 airplanes. This 
proposal would require an inspection of the fuel tube assembly of the 
auxiliary power unit (APU) for clearance from adjacent components; and 
inspecting the fuel tube assembly and the bleed air duct shroud for 
discrepancies (insufficient clearance, nicks, dents, chafing, or other 
damage); and related investigative and corrective actions if necessary. 
This proposal also would require relocating certain support clamps on 
the APU fuel tube assembly. This action is necessary to prevent a fuel 
leak caused by chafing of the APU fuel tube assembly, which could 
result in fire in the center wing area. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by June 18, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-285-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2003-NM-285-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 or 2000 or 
ASCII text.
    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, 1600 Stewart Avenue, suite 410, 
Westbury, New York.

FOR FURTHER INFORMATION CONTACT: Sarbhpreet Singh Sawhney, Aerospace 
Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York 
Aircraft Certification Office, 1600 Stewart Avenue, suite 410, 
Westbury, New York 11590; telephone (516) 228-7340; fax (516) 794-5531.

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:
     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.
     For each issue, state what specific change to the proposed 
AD is being requested.
     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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2003-NM-285-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. 2003-NM-285-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-8-101, -102, -103, -106, -201, -
202, -301, -311, and -315 airplanes. TCCA advises that an investigation 
of a fuel leak revealed chafing of the fuel tube assembly for the 
auxiliary power unit (APU). This fuel tube assembly is on the bleed air 
duct shroud, which is located in the center wing area where it is 
attached to a fairlead by two support clamps. It is possible that 
incorrect location of these support clamps may result in insufficient 
clearance between the fuel line and the bleed air duct, and/or between 
the fuel line and the gust lock cable. If there is insufficient 
clearance, the APU feed tube assembly can chafe, which could result in 
a fuel leak and possible fire in the center wing area.

Explanation of Relevant Service Information

    Bombardier has issued Service Bulletin 8-49-19, Revision A, dated 
July 7, 2003, which describes procedures for doing a visual inspection 
of the APU fuel tube assembly. This inspection includes examining the 
routing of the fuel tube assembly to ensure that the tube has 
sufficient clearance between the shroud of the bleed air duct and the 
gust lock cable; and inspecting the fuel tube assembly and the bleed 
air duct shroud for other discrepancies such as nicks, dents, chafing, 
or other damage. If the visual inspection shows no discrepancies, the 
service bulletin specifies to relocate the clamps on the APU fuel tube 
assembly. If the visual inspection shows discrepancies, the service 
bulletin describes procedures for related investigative and corrective 
actions before relocating the support clamps for the fuel tube 
assembly. These related investigative and corrective actions include:

[[Page 28864]]

     Blending out the damaged area and measuring the depth of 
the reworked area.
     For fuel tubes on which damage (nicks, chafing, or dents) 
is within acceptable limits: Doing an eddy current or fluorescent 
penetrant inspection for cracks. If cracks are found, or if the damage 
is outside the acceptable limits specified in the service bulletin: 
Reworking/repairing the tube assembly or replacing it with a new or 
serviceable tube assembly.
     Visually inspecting the replaced tube assembly for fuel 
leakage after rework or repair.
    Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition. TCCA 
classified this service bulletin as mandatory and issued Canadian 
airworthiness directive CF-2003-22, dated September 3, 2003, to ensure 
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 
section 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. We have 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 service bulletin described previously.

Cost Impact

    We estimate that up to 125 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 1 work 
hour per airplane to accomplish the proposed actions, and that the 
average labor rate is $65 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$8,125, or $65 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 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 2003-NM-285-
AD.

    Applicability: Model DHC-8-101, -102, -103, -106, -201, -202, -
301, -311, and -315 airplanes, serial number 003 through 585 
inclusive; certificated in any category; with auxiliary power unit 
(APU) installation per Standard Option Only (S.O.O.) 8155 or Change 
Request (CR) 849SO08155.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a fuel leak caused by chafing of the APU fuel tube 
assembly, which could result in fire in the center wing area, 
accomplish the following:

Inspection, Relocation and Related Investigative and Corrective Actions

    (a) Within 6 months after the effective date of this AD: Do a 
general visual inspection of the APU fuel tube assembly for 
discrepancies. The inspection includes examining the routing of the 
fuel tube assembly to ensure that the tube has sufficient clearance 
between the shroud of the bleed air duct and the gust lock cable; 
and inspecting the fuel tube assembly and the bleed air duct shroud 
for other discrepancies such as nicks, dents, chafing, or other 
damage. If the inspection shows no discrepancies, before further 
flight, relocate the clamps on the fuel tube assembly. If the 
inspection shows discrepancies, before further flight, do the 
applicable related investigative and corrective actions, and 
relocate the clamps on the fuel tube assembly. Accomplish all 
actions per the Accomplishment Instructions of Bombardier Service 
Bulletin 8-49-19, Revision A, dated July 7, 2003.

    Note 1: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Inspections Accomplished Per Previous Issue of Service Bulletin

    (b) Actions accomplished before the effective date of this AD 
per Bombardier Service Bulletin 8-49-19, dated May 13, 2003, are 
considered acceptable for compliance with the corresponding action 
specified in this AD.

Alternative Methods of Compliance

    (c) In accordance with 14 CFR 39.19, the Manager, New York 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Note 2: The subject of this AD is addressed in Canada 
airworthiness directive CF-2003-22, dated September 3, 2003.



[[Page 28865]]


    Issued in Renton, Washington, on May 11, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-11290 Filed 5-18-04; 8:45 am]
BILLING CODE 4910-13-P