Document ID: FAA-2009-0785-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Bombardier Model DHC 8 400 Series Airplanes
Posted Date: 2009-09-04T04:00Z

[Federal Register: September 4, 2009 (Volume 74, Number 171)]
[Proposed Rules]               
[Page 45787-45789]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04se09-20]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0785; Directorate Identifier 2009-NM-125-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).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above that would supersede an existing AD. 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:

    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.
* * * * *
    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 October 5, 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 W12-40, 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., 400 C[ocirc]te-Vertu Road West, Dorval, Qu[eacute]bec 
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

[[Page 45788]]

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-2009-0785; 
Directorate Identifier 2009-NM-125-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

    On June 3, 2009, we issued AD 2009-12-13, Amendment 39-15936 (74 FR 
27686, June 11, 2009). That AD required actions intended to address an 
unsafe condition on the products listed above.
    When we issued AD 2009-12-13, the eventual replacement of all 
elevator PCUs identified in paragraph (f)(1) of that AD was not 
required. We have now determined that further rulemaking is necessary 
for this action, and this proposed AD follows from that determination. 
We are proposing to mandate the optional terminating action in 
paragraph (f)(3) of AD 2009-12-13 in this AD. You may obtain further 
information by examining the MCAI in the AD docket.

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 61 products of U.S. registry.
    The actions that are required by AD 2009-12-13 and retained in this 
proposed AD take about 3 work-hours per product, at an average labor 
rate of $80 per work hour. Based on these figures, the estimated cost 
of the currently required actions is $240 per product.
    We estimate that it would take about 13 work-hours per product to 
comply with the new basic requirements of this proposed AD. The average 
labor rate is $80 per work-hour. Required parts would cost about $0 per 
product. Where the service information lists required parts costs that 
are uncovered under warranty, we have assumed that there will be no 
charge for these costs. 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 new actions 
of this proposed AD on U.S. operators to be $63,440, or $1,040 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 removing Amendment 39-15936 (74 FR 
27686, June 11, 2009) and adding the following new AD:

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket No. FAA-2009-
0785; Directorate Identifier 2009-NM-125-AD.

[[Page 45789]]

Comments Due Date

    (a) We must receive comments by October 5, 2009.

Affected ADs

    (b) The proposed AD supersedes AD 2009-12-13, Amendment 39-
15936.

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 continuing 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.

Restatement of Requirements of AD 2009-12-13, Without Optional 
Terminating Action

    (f) Unless already done, do the following actions.
    (1) Within 30 days after June 26, 2009 (the effective date of AD 
2009-12-13), 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 June 26, 2009, 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 (g) 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 operator 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) Actions accomplished before June 26, 2009, 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.

New Requirements of This AD: Actions and Compliance

    (g) Unless already done, within 2,000 flight hours or 12 months 
after the effective date of this AD, whichever occurs later, replace 
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 PCUs, P/N 390600-1007, having a serial number 
not specified in paragraph (f)(1) of this AD; or with PCUs, 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. This 
action terminates the requirements of paragraph (f)(1) of this AD.

FAA AD Differences

    Note 2: This AD differs from the MCAI and/or service information 
as follows: No differences.

Other FAA AD Provisions

    (h) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New 
York Aircraft Certification Office (ACO), 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 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. 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

    (i) 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.

    Issued in Renton, Washington, on August 26, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-21339 Filed 9-3-09; 8:45 am]

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