
[Federal Register Volume 74, Number 110 (Wednesday, June 10, 2009)]
[Proposed Rules]
[Pages 27476-27478]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-13505]


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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]
RIN 2120-AA64


Airworthiness Directives; Bombardier 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:

    Four aircraft have experienced a dual AC 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. 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 July 10, 2009.

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 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 W12-140, 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 or 425-227-1152.

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: 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:

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-2009-0526; 
Directorate Identifier 2009-NM-029-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 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-
2009-01, dated January 19, 2009 (referred to after this as ``the 
MCAI''), to correct an unsafe condition for the specified products. The 
MCAI states:

    Four aircraft have experienced a dual AC 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 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

[[Page 27477]]

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.

Relevant Service Information

    Bombardier has issued Service Bulletin 84-61-03, Revision `A,' 
dated September 18, 2008; and Bombardier Temporary Amendment (TA) 14, 
Issue 1, dated May 10, 2006, to the Dash 8 Q400 Airplane Flight Manual 
PSM 1-84-1A. 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 62 products of U.S. registry. We also estimate that 
it would take about 6 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Based on these figures, we estimate the cost of the proposed 
AD on 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 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. (Formerly de Havilland, Inc.): Docket No. FAA-2009-
0526; Directorate Identifier 2009-NM-029-AD.

Comments Due Date

    (a) We must receive comments by July 10, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-400, DHC-8-401, 
and DHC-8-402 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 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 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 AFM by inserting a copy of Bombardier 
Temporary Amendment (TA) 14, Issue 1, dated May 10, 2006, to the 
Dash 8 Q400 AFM PSM 1-84-1A. 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.

[[Page 27478]]

    (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 Modsum 4W163047, Revision B, dated August 
11, 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-S400 Modification Summary 
Package 4W163047 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, 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.

Related Information

    (h) Refer to MCAI Canadian Airworthiness Directive CF-2009-01, 
dated January 19, 2009; and Bombardier Service Bulletin 84-61-03, 
Revision `A,' dated September 18, 2008; for related information.

    Issued in Renton, Washington, on June 2, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-13505 Filed 6-9-09; 8:45 am]
BILLING CODE 4910-13-P


