
[Federal Register Volume 77, Number 180 (Monday, September 17, 2012)]
[Rules and Regulations]
[Pages 56989-56991]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-22335]


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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; 
Amendment 39-17192; AD 2012-18-15]
RIN 2120-AA64


Airworthiness Directives; Bombardier Inc. 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 certain 
Bombardier Inc. Model DHC-8-400 series airplanes. 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). This AD requires replacing 
the TMU. We are issuing this AD to prevent loss of the automatic de-
icing mode and consequent increased workload for the flightcrew, which, 
depending on additional failures, could lead to loss of control of the 
airplane.

DATES: This AD becomes effective October 22, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 22, 
2012.

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: 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:

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 20, 2012 (77 
FR 16191). That NPRM proposed 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 [Transport Canada Civil Aviation (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 flightcrew, 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We have considered the comments received.

Support for the NPRM (77 FR 16191, March 20, 2012)

    The Air Line Pilots Association, International (ALPA) supports the 
intent of the NPRM (77 FR 16191, March 20, 2012).

Request To Withdraw the NPRM (77 FR 16191, March 20, 2012)

    Katherine Carpenter, a private citizen, stated that it seems 
unnecessary to require a law for replacing a faulty part, and that 
common sense indicates that companies should replace the parts to limit 
their liability in case of an accident.
    We infer that the commenter was requesting that we withdraw the 
NPRM (77 FR 16191, March 20, 2012). According to section 39.1 
(``Airworthiness Directives'') of the Federal Aviation Regulations (14 
CFR 39.1), we issue an AD based on our finding that an unsafe condition 
exists and is likely to exist or develop in products of the same type 
design. We have the responsibility, placed on us by the Federal 
Aviation Act (49 U.S.C. App. 1301 et seq.), to make an unsafe 
condition--whether resulting from maintenance, design defect, or 
otherwise--the subject of an AD, and to issue an AD when that unsafe 
condition is likely to exist or develop on other products of the same 
type design.
    Further, it is within our authority to issue ADs to require 
corrective actions to address unsafe conditions that are not being 
addressed (or not addressed adequately) by operators' normal 
maintenance procedures. An AD is the appropriate means for mandating 
this action. As a result, we are issuing this AD to eliminate the 
identified unsafe condition by requiring replacement of the TMU.

Request To Reduce Compliance Time

    ALPA requested that the compliance time be reduced from 3,000 
flight hours or 18 months, to 1,000 flight hours or 6 months, in order 
to reduce the operating exposure of the affected airplanes to two 
winter seasons.
    We disagree to reduce the compliance time for two reasons. First, 
the DEICE PRESS or DEICE TIMER caution lights annunciate a failure to 
the flightcrew; the airplane flight manual (AFM) provides procedures to 
address this failure and instructs the flightcrew to use the manual 
mode of the pneumatic ice protection system and to exit icing 
conditions as soon as possible. While an

[[Page 56990]]

increased pilot workload is classified as ``major'' in a fictional 
hazard assessment, the actual number of these events decreases that 
probability to a ``medium'' safety risk. Second, the manufacturer 
indicated that the mean time between TMU replacements has been 3,000 
flight hours, consistent with the compliance time for this AD action. 
For these reasons, we determined that the compliance time is justified, 
and we have not changed the final rule in this regard.

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
the AD as proposed--except for minor editorial changes. We have 
determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (77 FR 16191, March 20, 2012) for correcting the unsafe condition; 
and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (77 FR 16191, March 20, 2012).

Costs of Compliance

    We estimate that this AD will affect about 81 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 $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 this AD to the 
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 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 that 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);
    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 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 (77 FR 16191, March 20, 
2012), 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

    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:

2012-18-15 Bombardier, Inc.: Amendment 39-17192. Docket No. FAA-
2012-0267; Directorate Identifier 2011-NM-174-AD.

(a) Effective Date

    This airworthiness directive (AD) becomes effective October 22, 
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(TMU), 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 TMU. We are issuing this 
AD to prevent loss of the automatic de-icing mode and consequent 
increased workload for the flightcrew, 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) Replacement of 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.

(h) Parts Installation Prohibition

    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,

[[Page 56991]]

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.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the following service 
information under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use the following service information to do the 
actions required by this AD, unless the AD specifies otherwise.
    (i) Bombardier Service Bulletin 84-30-14, dated May 20, 2011.
    (ii) Reserved.
    (3) For service information identified in this 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.
    (4) You may review copies of the service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. 
For information on the availability of this material at the FAA, 
call 425-227-1221.
    (5) 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 an NARA facility, 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 September 4, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-22335 Filed 9-14-12; 8:45 am]
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