Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes

[Federal Register Volume 74, Number 111 (Thursday, June 11, 2009)]
[Rules and Regulations]
[Pages 27686-27689]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-13570]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0530; Directorate Identifier 2009-NM-079-AD; 
Amendment 39-15936; AD 2009-12-13]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-400 Series 
Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This 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:

    There has been one case reported of failure of a shaft 
(tailstock) on an elevator Power Control Unit (PCU), Part Number (P/
N) 390600-1007. Continued actuation of the affected PCU caused 
damage to the surrounding structure. * * *
    Each elevator surface has three PCUs, powered by separate 
independent hydraulic systems, and a single elevator PCU shaft 
failure may remain dormant. Such a dormant loss of redundancy, 
coupled with the potential for a failed shaft to produce collateral 
damage, including damage to hydraulic lines, could possibly affect 
the controllability of the aircraft.
* * * * *
This AD requires actions that are intended to address the unsafe 
condition described in the MCAI.

DATES: This AD becomes effective June 26, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of June 26, 2009.
    We must receive comments on this AD by July 13, 2009.

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.
    <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 W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.

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 AD, the regulatory evaluation, 
any comments received, and other information. The street address for

[[Page 27687]]

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 Propulsion 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

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Airworthiness Directive CF-
2009-16, dated April 20, 2009 (referred to after this as ``the MCAI''), 
to correct an unsafe condition for the specified products. The MCAI 
states:

    There has been one case reported of failure of a shaft 
(tailstock) on an elevator Power Control Unit (PCU), Part Number (P/
N) 390600-1007. Continued actuation of the affected PCU caused 
damage to the surrounding structure. Subsequent investigation 
determined that the failure was the result of a material defect and 
that the shafts installed on a total of 88 suspect PCUs * * * may 
contain a similar defect.
    Each elevator surface has three PCUs, powered by separate 
independent hydraulic systems, and a single elevator PCU shaft 
failure may remain dormant. Such a dormant loss of redundancy, 
coupled with the potential for a failed shaft to produce collateral 
damage, including damage to hydraulic lines, could possibly affect 
the controllability of the aircraft.
    This directive mandates an identification check for elevator PCU 
serial numbers, a daily check for correct operation of all suspect 
PCUs and, finally, replacement of all suspect PCUs.

You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    Bombardier has issued Service Bulletin 84-27-32, Revision A, dated 
January 18, 2008; and Q400 All Operator Message 217B, dated April 26, 
2007. 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 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 issuing this AD because we 
evaluated all pertinent information and determined the unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Differences Between the 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 required 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 AD.

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because the 
power control unit (PCU), part number P/N 390600-1007, has been 
identified as having a shaft (tailstock) failure. Each elevator on the 
affected model airplane contains three PCUs which are powered 
independently as a means of redundancy. Due to this built-in 
redundancy, a fracture to the elevator PCU shaft can remain undetected 
while decreasing airplane safety. Furthermore, the continual use of the 
failed shaft in the PCUs can result in damage to additional systems 
such as hydraulic lines, and could result in loss of controllability of 
the airplane. Since this is a dormant failure, it is necessary to 
identify and replace any defective units within 30 days after the 
effective date of this AD. Therefore, we determined that notice and 
opportunity for public comment before issuing this AD are impracticable 
and that good cause exists for making this amendment effective in fewer 
than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and opportunity for public 
comment. We invite you to send any written relevant data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include ``Docket No. FAA-2009-0530; Directorate 
Identifier 2009-NM-079-AD'' at the beginning of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this AD. We will consider all 
comments received by the closing date and may amend this AD because of 
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 AD.

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 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); 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 AD and placed it in the AD docket.

[[Page 27688]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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:

2009-12-13 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-15936. Docket No. FAA-2009-0530; Directorate Identifier 2009-NM-
079-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective June 26, 
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 4135 through 4149 inclusive.

Subject

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

Reason

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

    There has been one case reported of failure of a shaft 
(tailstock) on an elevator Power Control Unit (PCU), Part Number (P/
N) 390600-1007. Continued actuation of the affected PCU caused 
damage to the surrounding structure. Subsequent investigation 
determined that the failure was the result of a material defect and 
that the shafts installed on a total of 88 suspect PCUs * * * may 
contain a similar defect.
    Each elevator surface has three PCUs, powered by separate 
independent hydraulic systems, and a single elevator PCU shaft 
failure may remain dormant. Such a dormant loss of redundancy, 
coupled with the potential for a failed shaft to produce collateral 
damage, including damage to hydraulic lines, could possibly affect 
the controllability of the aircraft.
    This directive mandates an identification check for elevator PCU 
serial numbers, a daily check for correct operation of all suspect 
PCUs and, finally, replacement of all suspect PCUs.

Actions and Compliance

    (f) Unless already done, do the following actions.
    (1) Within 30 days after the effective date of this AD, inspect 
the serial number of each of the six installed elevator PCUs having 
P/N 390600-1007. If one or more of the six installed elevator PCUs, 
P/N 390600-1007, have any of the PCU serial numbers 238, 698, 783 
through 788 inclusive, 790, 793, 795, 802, 806, 807, 810, 820 
through 823 inclusive, 826 through 828 inclusive, 831, 835, 838, 
840, 886 through 889 inclusive, or 898 through 955 inclusive; 
without a suffix ``A'' after the serial number: Within 30 days after 
the effective date of this AD, perform a check for the correct 
operation of all installed elevator PCUs in accordance with the 
procedures detailed in Appendix A, B, or C of Bombardier Q400 All 
Operator Message 217B, dated April 26, 2007. Repeat the check 
thereafter before the first flight of each day until the replacement 
specified in paragraph (f)(3) of this AD is done. The checks in 
Appendix A and B of Bombardier Q400 All Operator Message 217B, dated 
April 26, 2007, must be performed by the flight crew, while the 
check specified in Appendix C of the all operators message must be 
performed by certificated maintenance personnel.

    Note 1:  Suffix ``A'' after the serial number indicates that the 
PCU has already passed a magnetic particle inspection and is cleared 
for continued use.

    (2) If incorrect operation of any elevator PCU is found during 
any check required by paragraph (f)(1) of this AD, before further 
flight, replace the elevator PCU with a PCU, P/N 390600-1007, having 
a serial number not specified in paragraph (f)(1) of this AD; or 
with a PCU, P/N 390600-1007, having the suffix ``A'' after the 
serial number; in accordance with the Accomplishment Instructions of 
Bombardier Service Bulletin 84-27-32, Revision A, dated January 18, 
2008.
    (3) Replacing all PCUs, P/N 390600-1007, having a serial number 
specified in paragraph (f)(1) of this AD, and not having suffix 
``A'' after the serial number, with a PCU, P/N 390600-1007, having a 
serial number not specified in paragraph (f)(1) of this AD; or with 
a PCU, P/N 390600-1007, having the suffix ``A'' after the serial 
number; in accordance with the Accomplishment Instructions of 
Bombardier Service Bulletin 84-27-32, Revision A, dated January 18, 
2008; terminates the requirements of paragraph (f)(1) of this AD.
    (4) Actions accomplished before the effective date of this AD 
according to Bombardier Service Bulletin 84-27-32, dated May 1, 
2007, are considered acceptable for compliance with the 
corresponding action specified in this AD.

FAA AD Differences

    Note 2:  This AD differs from the MCAI and/or service 
information as follows: Unlike the Canadian airworthiness directive 
CF-2009-16, dated April 20, 2009, this AD does not require the 
eventual replacement of all elevator PCUs identified in paragraph 
(f)(1) of this AD. The planned compliance times for those actions 
would allow enough time to provide notice and opportunity for prior 
public comment on the merits of those actions. Therefore, we are 
considering further rulemaking to address this issue.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
Airframe and Propulsion Branch, ANE-171, 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: Cesar Gomez, Aerospace 
Engineer, Airframe and Propulsion 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. 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. 
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.
    (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-2009-16, 
dated April 20, 2009; Bombardier Service Bulletin 84-27-32, Revision 
A, dated January 18, 2008; and Bombardier Q400 All Operator Message 
217B, dated April 26, 2007; for related information.

Material Incorporated by Reference

    (i) You must use Bombardier Service Bulletin 84-27-32, Revision 
A, dated January 18, 2008, or Bombardier Q400 All Operator Message 
217B, dated April 26, 2007 to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this 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 [email protected]; Internet http://www.bombardier.com.
    (3) You may review copies of the 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.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and

[[Page 27689]]

Records Administration (NARA). For information on the availability 
of this material at NARA, 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 June 3, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-13570 Filed 6-10-09; 8:45 am]
BILLING CODE 4910-13-P

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