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).
-----------------------------------------------------------------------
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 Cote-Vertu Road West, Dorval, Quebec 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 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: