Document ID: FAA-2009-0526-0005
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes
Posted Date: 2009-09-09T04:00Z

[Federal Register: September 9, 2009 (Volume 74, Number 173)]
[Rules and Regulations]               
[Page 46317-46319]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09se09-6]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0526; Directorate Identifier 2009-NM-029-AD; 
Amendment 39-16008; AD 2009-18-12]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier 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:

    Four aircraft have experienced a dual AC [alternating current] 
generator shutdown, caused by a broken propeller de-ice bus bar 
which short-circuited with the backplate assembly.
    * * * A short circuit can cause a dual AC generator shutdown 
that, particularly in conjunction with an engine failure in icing 
conditions, could result in reduced controllability of the aircraft.

* * * * *
    Reduced controllability of the airplane in certain operating 
conditions affects continued safe flight and landing. We are issuing 
this AD to require actions to correct the unsafe condition on these 
products.

DATES: This AD becomes effective October 14, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of October 14, 
2009.

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: Wing Chan, Aerospace Engineer, 
Aerospace Engineer, Systems and Flight Test Branch, ANE-172, FAA, New 
York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, 
Westbury, New York 11590; telephone (516) 228-7311; 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 June 10, 2009 (74 FR 
27476). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    Four aircraft have experienced a dual AC [alternating current] 
generator shutdown, caused by a broken propeller de-ice bus bar 
which short-circuited with the backplate assembly.
    It was subsequently determined that any friction or contact 
between a propeller de-ice bus bar and the backplate assembly can 
cause an intermittent short circuit. Such a short circuit can cause 
a dual AC generator shutdown that, particularly in conjunction with 
an engine failure in icing conditions, could result in reduced 
controllability of the aircraft.
    This [Transport Canada Civil Aviation] directive mandates 
revision of the Airplane Flight Manual (AFM) to introduce a 
procedure that restores AC power following a failure of No. 1 and 
No. 2 AC generators with propeller de-ice on. Additionally, in order 
to prevent similar dual AC generator shutdowns, it mandates the 
application of sealant as insulation between the propeller de-ice 
bus bars and the backplate assembly.

    Reduced controllability of the airplane in certain operating 
conditions affects continued safe flight and landing. 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 62 products of U.S. registry. 
We also estimate that it will take about 6 work-hours per product to 
comply with the basic requirements of this AD. The average labor rate 
is $80 per work-hour. Based on these figures, we estimate the

[[Page 46318]]

cost of this AD to the U.S. operators to be $29,760, or $480 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:

2009-18-12 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-16008. Docket No. FAA-2009-0526; Directorate Identifier 2009-NM-
029-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective October 
14, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier 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 4154 inclusive.

Subject

    (d) Air Transport Association (ATA) of America Code 61: 
Propellers/Propulsors.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:
    Four aircraft have experienced a dual AC [alternating current] 
generator shutdown, caused by a broken propeller de-ice bus bar 
which short-circuited with the backplate assembly.
    It was subsequently determined that any friction or contact 
between a propeller de-ice bus bar and the backplate assembly can 
cause an intermittent short circuit. Such a short circuit can cause 
a dual AC generator shutdown that, particularly in conjunction with 
an engine failure in icing conditions, could result in reduced 
controllability of the aircraft.
    This [Transport Canada Civil Aviation] directive mandates 
revision of the Airplane Flight Manual (AFM) to introduce a 
procedure that restores AC power following a failure of No. 1 and 
No. 2 AC generators with propeller de-ice on. Additionally, in order 
to prevent similar dual AC generator shutdowns, it mandates the 
application of sealant as insulation between the propeller de-ice 
bus bars and the backplate assembly.
    Reduced controllability of the airplane in certain operating 
conditions affects continued safe flight and landing.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 30 days after the effective date of this AD, revise 
the Limitations Section of the Bombardier Dash 8 Q400 AFM, PSM 1-84-
1A, by inserting a copy of Bombardier Dash 8 Q400 Temporary 
Amendment (TA) 14, Issue 1, dated May 10, 2006. When the information 
in Bombardier TA 14, Issue 1, dated May 10, 2006, is included in the 
general revisions of the AFM, the general revisions may be inserted 
in the AFM and the TA may be removed.
    (2) Within 5,000 flight hours after the effective date of this 
AD: Apply sealant between the bus bar assemblies and the backplate 
assembly by incorporating Bombardier DHC-8-400 Modification Summary 
4-163047, Revision B, dated August 22, 2008, in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin 84-61-03, 
Revision `A,' dated September 18, 2008.
    (3) Incorporating Bombardier DHC-8-400 Modification Summary 
Package 4-163047 before the effective date of this AD in accordance 
with Bombardier Service Bulletin 84-61-03, dated April 27, 2007, is 
considered acceptable for compliance with the requirements of 
paragraph (f)(2) 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 (ACO), 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: Wing Chan, Aerospace 
Engineer, Systems and Flight Test Branch, ANE-172, FAA, New York 
ACO, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; 
telephone (516) 228-7311; 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.
    (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, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

[[Page 46319]]

Related Information

    (h) Refer to MCAI Canadian Airworthiness Directive CF-2009-01, 
dated January 19, 2009; Bombardier Dash 8 Q400 TA 14, Issue 1, dated 
May 10, 2006; and Bombardier Service Bulletin 84-61-03, Revision 
`A,' dated September 18, 2008; for related information.

Material Incorporated by Reference

    (i) You must use Bombardier Dash 8 Q400 Temporary Amendment 14, 
Issue 1, dated May 10, 2006; and Bombardier Service Bulletin 84-61-
03, Revision `A,' dated September 18, 2008; as applicable; 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 thd.qseries@aero.bombardier.com; 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 or 425-227-1152.
    (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 August 18, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-20836 Filed 9-8-09; 8:45 am]

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