[Federal Register Volume 76, Number 60 (Tuesday, March 29, 2011)]
[Proposed Rules]
[Pages 17362-17364]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-7289]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0260; Directorate Identifier 2010-NM-242-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc. 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:

    Several reports have been received on the elevator power control 
units (PCUs) where the shaft (tailstock) swaged bearing liners had 
shown a higher than normal rate of wear. Investigation revealed that 
the excessive wear was due to the paint contamination between the 
bearing roller and bearing liner. The bearing paint contamination is 
known to be abrasive and could seize the bearing.
    This condition, if not corrected, could lead to excessive 
airframe vibrations and difficulties in aircraft pitch control.
* * * * *
    The unsafe condition is loss of controllability. 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 May 13, 2011.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

[[Page 17363]]

    <bullet> Fax: (202) 493-2251.
    <bullet> 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.
    <bullet> Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 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; e-mail <a href="/cdn-cgi/l/email-protection#611509054f10120413080412210004130e4f030e0c030013050804134f020e0c"><span class="__cf_email__" data-cfemail="65110d014b141600170c0016250400170a4b070a08070417010c00174b060a08">[email protected]</span></a>; 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 (ACO), 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-2011-0260; 
Directorate Identifier 2010-NM-242-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, which is the aviation authority 
for Canada, has issued Canadian Airworthiness Directive CF-2010-28, 
dated August 20, 2010 (referred to after this as ``the MCAI''), to 
correct an unsafe condition for the specified products. The MCAI 
states:

    Several reports have been received on the elevator power control 
units (PCUs) where the shaft (tailstock) swaged bearing liners had 
shown a higher than normal rate of wear. Investigation revealed that 
the excessive wear was due to the paint contamination between the 
bearing roller and bearing liner. The bearing paint contamination is 
known to be abrasive and could seize the bearing.
    This condition, if not corrected, could lead to excessive 
airframe vibrations and difficulties in aircraft pitch control.
    This directive mandates a free-play check of the shaft swaged 
bearing installed in the elevator PCU tailstock end and replacement 
of the shaft swaged bearings if excessive free-play is found.

The unsafe condition is loss of controllability. You may obtain further 
information by examining the MCAI in the AD docket.

Relevant Service Information

    Bombardier has issued Service Bulletin 84-27-52, dated May 25, 
2010. 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 66 products of U.S. registry. We also estimate that 
it would take about 2 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $85 per 
work-hour. Based on these figures, we estimate the cost of the proposed 
AD on U.S. operators to be $11,220, or $170 per product.
    In addition, we estimate that any necessary follow-on actions would 
take about 3 work-hours and require parts costing $33, for a cost of 
$288 per product. We have no way of determining the number of products 
that may need these actions.

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

[[Page 17364]]

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-2011-0260; Directorate Identifier 
2010-NM-242-AD.

Comments Due Date

    (a) We must receive comments by May 13, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, 
and -402 airplanes having serial numbers (S/Ns) 4001 through 4304 
inclusive; certificated in any category.

Subject

    (d) Air Transport Association (ATA) of America Code 27: Flight 
controls.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    Several reports have been received on the elevator power control 
units (PCUs) where the shaft (tailstock) swaged bearing liners had 
shown a higher than normal rate of wear. Investigation revealed that 
the excessive wear was due to the paint contamination between the 
bearing roller and bearing liner. The bearing paint contamination is 
known to be abrasive and could seize the bearing.
    This condition, if not corrected, could lead to excessive 
airframe vibrations and difficulties in aircraft pitch control.
* * * * *
The unsafe condition is loss of controllability.

Compliance

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

Free-Play Check and Corrective Actions

    (g) At the applicable time specified in paragraph (g)(1) or 
(g)(2) of this AD: Perform a free-play check for any shaft swaged 
bearing having part number (P/N) MS14103-7 that is installed in the 
tailstock end of each elevator PCU (three PCUs per elevator 
surface), having P/Ns 390600-1007 and 390600-1009, in accordance 
with paragraph 3.B., Part A, of Bombardier Service Bulletin 84-27-
52, dated May 25, 2010.
    (1) For airplanes that have accumulated 8,000 or more total 
flight hours as of the effective date of this AD: Within 2,000 
flight hours after the effective date of this AD.
    (2) For airplanes that have accumulated less than 8,000 total 
flight hours as of the effective date of this AD: Within 6,000 
flight hours after the effective date of this AD or before the 
accumulation of 10,000 total flight hours, whichever occurs first.
    (h) If, during the check required by paragraph (g) of this AD, 
the bearing free-play is within the limits specified in Bombardier 
Service Bulletin 84-27-52, dated May 25, 2010, no further action is 
required by this AD.
    (i) If, during the check required by paragraph (g) of this AD, 
the bearing free-play exceeds the limits specified in Bombardier 
Service Bulletin 84-27-52, dated May 25, 2010: Before further 
flight, replace the elevator PCU with a serviceable one, in 
accordance with paragraph 3.B., Part B, of Bombardier Service 
Bulletin 84-27-52, dated May 25, 2010.

FAA AD Differences

    Note 1:  This AD differs from the MCAI and/or service 
information as follows: No differences.

Other FAA AD Provisions

    (j) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York ACO, ANE-170, 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: 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.

Related Information

    (k) Refer to MCAI Canadian Airworthiness Directive CF-2010-28, 
dated August 20, 2010; and Bombardier Service Bulletin 84-27-52, 
dated May 25, 2010; for related information.

    Issued in Renton, Washington, on March 21, 2011.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-7289 Filed 3-28-11; 8:45 am]
BILLING CODE 4910-13-P


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