
[Federal Register: March 23, 2010 (Volume 75, Number 55)]
[Proposed Rules]               
[Page 13682-13684]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23mr10-21]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0273; Directorate Identifier 2009-NM-134-AD]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed AD results from mandatory 
continuing airworthiness information (MCAI) originated by an aviation 
authority of another country to identify and correct an unsafe 
condition on an aviation product. The MCAI describes the unsafe 
condition as:

Two in-service incidents have been reported on DHC-8 Series 400 
aircraft in which the nose landing gear (NLG) trailing arm pivot pin 
retention bolt (part number NAS6204-13D) was damaged. One incident 
involved the left hand NLG tire which ruptured on take-off. 
Investigation determined that the retention bolt failure was due to 
repeated contact of the castellated nut with the towing device 
including both the towbar and the towbarless rigs. The loss of the 
retention bolt allowed the pivot pin to migrate from its normal 
position and resulted in contact with and rupture of the tire. The 
loss of the pivot pin could compromise retention of the trailing arm 
and could result in a loss of directional control due to loss of 
nose wheel steering. The loss of an NLG tire or the loss of 
directional control could adversely affect the aircraft during take 
off or landing.
* * * * *

    The proposed AD would require actions that are intended to address 
the unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by May 7, 2010.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room

[[Page 13683]]

W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Bombardier, Inc., 400 C[ocirc]te-Vertu Road West, Dorval, Qu[eacute]bec 
H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-7401; e-mail 
thd.qseries@aero.bombardier.com; Internet http://www.bombardier.com. 
You may review copies of the referenced service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 
Washington. For information on the availability of this material at the 
FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (telephone (800) 647-5527) is 
in the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Richard Beckwith, Aerospace Engineer, 
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7302; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0273; 
Directorate Identifier 2009-NM-134-AD;'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We have lengthened the 30-day comment period for proposed ADs that 
address MCAI originated by aviation authorities of other countries to 
provide adequate time for interested parties to submit comments. The 
comment period for these proposed ADs is now typically 45 days, which 
is consistent with the comment period for domestic transport ADs.
    We will post all comments we receive, without change, to  http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Airworthiness Directive CF-
2009-29, dated June 29, 2009 (referred to after this as ``the MCAI''), 
to correct an unsafe condition for the specified products. The MCAI 
states:

Two in-service incidents have been reported on DHC-8 Series 400 
aircraft in which the nose landing gear (NLG) trailing arm pivot pin 
retention bolt (part number NAS6204-13D) was damaged. One incident 
involved the left hand NLG tire which ruptured on take-off. 
Investigation determined that the retention bolt failure was due to 
repeated contact of the castellated nut with the towing device 
including both the towbar and the towbarless rigs. The loss of the 
retention bolt allowed the pivot pin to migrate from its normal 
position and resulted in contact with and rupture of the tire. The 
loss of the pivot pin could compromise retention of the trailing arm 
and could result in a loss of directional control due to loss of 
nose wheel steering. The loss of an NLG tire or the loss of 
directional control could adversely affect the aircraft during take 
off or landing.
To prevent the potential failure of the pivot pin retention bolt, 
Bombardier Aerospace has developed a modification which includes a 
new retention bolt, a reverse orientation of the retention bolt and 
a rework of the weight on wheel (WOW) proximity sensor cover to 
provide clearance for the re-oriented retention bolt.

    You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    Bombardier has issued Service Bulletin 84-32-65, Revision A, dated 
March 2, 2009. The actions described in this service information are 
intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have proposed different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a Note within the proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 63 products of U.S. registry. We also estimate that 
it would take about 3 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $85 per 
work-hour. Required parts would cost about $100 per product. Based on 
these figures, we estimate the cost of the proposed AD on U.S. 
operators to be $22,365, or $355 per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

[[Page 13684]]

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new AD:

Bombardier, Inc.: Docket No. FAA-2010-0273; Directorate Identifier 
2009-NM-134-AD.

Comments Due Date

    (a) We must receive comments by May 7, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier, Inc. Model DHC-8-400, DHC-8-
401, and DHC-8-402 series airplanes, certificated in any category; 
serial numbers 4001, 4003, 4004, 4006, and 4008 through 4238 
inclusive.

Subject

    (d) Air Transport Association (ATA) of America Code 32: Landing 
gear.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:
    Two in-service incidents have been reported on DHC-8 Series 400 
aircraft in which the nose landing gear (NLG) trailing arm pivot pin 
retention bolt (part number NAS6204-13D) was damaged. One incident 
involved the left hand NLG tire which ruptured on take-off. 
Investigation determined that the retention bolt failure was due to 
repeated contact of the castellated nut with the towing device 
including both the towbar and the towbarless rigs. The loss of the 
retention bolt allowed the pivot pin to migrate from its normal 
position and resulted in contact with and rupture of the tire. The 
loss of the pivot pin could compromise retention of the trailing arm 
and could result in a loss of directional control due to loss of 
nose wheel steering. The loss of an NLG tire or the loss of 
directional control could adversely affect the aircraft during take 
off or landing.
    To prevent the potential failure of the pivot pin retention 
bolt, Bombardier Aerospace has developed a modification which 
includes a new retention bolt, a reverse orientation of the 
retention bolt and a rework of the weight on wheel (WOW) proximity 
sensor cover to provide clearance for the re-oriented retention 
bolt.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 2,000 flight hours after the effective date of this 
AD: Modify the NLG trailing arm by incorporating Bombardier 
Modification Summary 4-113599, in accordance with the Accomplishment 
Instructions of Bombardier Service Bulletin 84-32-65, Revision A, 
dated March 2, 2009.
    (2) Incorporating Bombardier Modification Summary 4-113599 in 
accordance with the Accomplishment Instructions of Bombardier 
Service Bulletin 84-32-65, dated December 17, 2008, is also 
acceptable for compliance with the requirements of paragraph (f)(1) 
of this AD if done before the effective date of this AD.

FAA AD Differences

    Note 1:  This AD differs from the MCAI and/or service 
information as follows: No differences.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York Aircraft Certification Office, ANE-170, FAA, has the authority 
to approve AMOCs for this AD, if requested using the procedures 
found in 14 CFR 39.19. Send information to ATTN: Program Manager, 
Continuing Operational Safety, FAA, New York ACO, 1600 Stewart 
Avenue, Suite 410, Westbury, New York, 11590; telephone 516-228-
7300; fax 516-794-553. Before using any approved AMOC on any 
airplane to which the AMOC applies, notify your principal 
maintenance inspector (PMI) or principal avionics inspector (PAI), 
as appropriate, or lacking a principal inspector, your local Flight 
Standards District Office. The AMOC approval letter must 
specifically reference this AD.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act (44 
U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has 
approved the information collection requirements and has assigned 
OMB Control Number 2120-0056.

Related Information

    (h) Refer to MCAI Canadian Airworthiness Directive CF-2009-29, 
dated June 29, 2009; and Bombardier Service Bulletin 84-32-65, 
Revision A, dated March 2, 2009; for related information.

    Issued in Renton, Washington, on March 17, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-6306 Filed 3-22-10; 8:45 am]
BILLING CODE 4910-13-P

