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

[Federal Register Volume 75, Number 120 (Wednesday, June 23, 2010)]
[Rules and Regulations]
[Pages 35622-35624]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-14984]


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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; 
Amendment 39-16335; AD 2010-13-04]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This 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.
* * * * *
    We are issuing this AD to require actions to correct the unsafe 
condition on these products.

DATES: This AD becomes effective July 28, 2010.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of July 28, 
2010.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC.

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: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on March 23, 2010 (75 
FR 13682). That NPRM proposed to correct

[[Page 35623]]

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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM or on the determination of 
the cost to the public.

Conclusion

    We reviewed the available data and determined that air safety and 
the public interest require adopting the AD as proposed.

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 required different actions in this AD from those 
in the MCAI in order to follow our FAA policies. Any such differences 
are highlighted in a Note within the AD.

Costs of Compliance

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

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD will 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 AD:
    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 AD and placed it in the AD docket.

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 the NPRM, 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.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2010-13-04 Bombardier, Inc.: Amendment 39-16335. Docket No. FAA-
2010-0273; Directorate Identifier 2009-NM-134-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective July 28, 
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.

[[Page 35624]]

    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 516-794-5531. 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.

Material Incorporated by Reference

    (i) You must use Bombardier Service Bulletin 84-32-65, Revision 
A, dated March 2, 2009, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this 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 [email protected]; Internet http://www.bombardier.com.
    (3) You may review copies of the 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.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on June 10, 2010.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-14984 Filed 6-22-10; 8:45 am]
BILLING CODE 4910-13-P

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