
[Federal Register Volume 77, Number 54 (Tuesday, March 20, 2012)]
[Proposed Rules]
[Pages 16191-16193]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-6626]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0267; Directorate Identifier 2011-NM-174-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Inc. 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 
certain Bombardier Inc. Model DHC-8-400 series airplanes. This proposed 
AD was prompted by reports that the automatic de-icing mode became 
unavailable due to a failure of the timer and monitor unit (TMU). This 
proposed AD would require replacing the TMU. We are proposing this AD 
to prevent loss of the automatic de-icing mode and consequent increased 
workload for the flight crew, which, depending on additional failures, 
could lead to loss of control of the airplane.

DATES: We must receive comments on this proposed AD by May 4, 2012.

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., Q-Series Technical Help Desk, 123 Garratt Boulevard, 
Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-4000; fax 416-375-
4539; email 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: Cesar Gomez, 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) 228-7318; 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-2012-0267; 
Directorate Identifier 2011-NM-174-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

[[Page 16192]]

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-
2011-34, dated August 16, 2011 (referred to after this as ``the 
MCAI''), to correct an unsafe condition for the specified products. The 
MCAI states:

There have been multiple reports of in-service incidents where the 
automatic deicing mode became unavailable due to a failure of the 
Timer and Monitor Unit (TMU).

Investigation has revealed that the failures were attributed to 
overstressed capacitors installed in the circuit board of the TMU 
``Module 300'' power supply. The failure of the capacitors leads to 
failure of the TMU ``Module 300'' power supply and subsequent loss 
of the automatic deicing mode.

This [TCCA] directive mandates the replacement of the TMU, part 
number (P/N) 4100S018-06, with a new improved unit, P/N 4100S018-07.

The unsafe condition is loss of the automatic de-icing mode and 
consequent increased workload for the flight crew, which, depending on 
additional failures, could lead to loss of control of the airplane. You 
may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

    Bombardier, Inc. has issued Service Bulletin 84-30-14, dated May 
20, 2011. 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.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 81 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 $0 per product. Where the 
service information lists required parts costs that are covered under 
warranty, we have assumed that there will be no charge for these parts. 
As we do not control warranty coverage for affected parties, some 
parties may incur costs higher than estimated here. Based on these 
figures, we estimate the cost of the proposed AD on U.S. operators to 
be $20,655, or $255 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);
    3. Will not affect intrastate aviation in Alaska; and
    4. 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-2012-0267; Directorate Identifier 
2011-NM-174-AD.

(a) Comments Due Date

    We must receive comments by May 4, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -
402 airplanes, certificated in any category, serial numbers 4001 and 
subsequent, equipped with Aerazur timer and monitor unit, part 
number (P/N) 4100S018-06.

(d) Subject

    Air Transport Association (ATA) of America Code 30: Ice and rain 
protection.

(e) Reason

    This AD was prompted by reports that the automatic de-icing mode 
became unavailable due to a failure of the timer and monitor unit 
(TMU). We are issuing this AD to prevent loss of the automatic de-
icing mode and consequent increased workload for the flight crew, 
which, depending on additional failures, could lead to loss of 
control of the airplane.

(f) Compliance

    You are responsible for having the actions required by this AD 
performed within the compliance times specified, unless the actions 
have already been done.

(g) Replace the TMU

    Within 3,000 flight hours or 18 months after the effective date 
of this AD, whichever occurs first: Replace TMU P/N 4100S018-06 with 
new TMU P/N 4100S018-07, by incorporating Bombardier ModSum 4-
126525, in accordance with the Accomplishment Instructions of 
Bombardier Service Bulletin 84-30-14, dated May 20, 2011.

[[Page 16193]]

(h) Parts Installation

    As of the effective date of this AD, no person may install a 
TMU, P/N 4100S018-06, on any airplane.

(i) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York Aircraft Certification Office (ACO), ANE-170, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the ACO, send it 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, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
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.

(j) Related Information

    Refer to MCAI Canadian Airworthiness Directive CF-2011-34, dated 
August 16, 2011; and Bombardier Service Bulletin 84-30-14, dated May 
20, 2011; for related information.

    Issued in Renton, Washington, on March 7, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-6626 Filed 3-19-12; 8:45 am]
BILLING CODE 4910-13-P


