AD 2011-24-03

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 series airplanes. 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 reported incident where the main landing gear (MLG) failed to extend during testing of the MLG alternate release system. Investigation revealed that the door release lever bushing was worn, causing an increase in the lateral movement of the release cable system. An increase in free-play within the release cable system would cause additional wear to the door release lever bushing and may lead to the turnbuckle fouling against the nacelle frame. The bushing wear at the door release lever and turnbuckle fouling could cause a failure in the alternate release system, preventing the landing gear from extending in the case of a failure of the normal MLG extension/retraction system.
* * * * *
The unsafe condition is loss of control during landing. We are issuing this AD to require actions to correct the unsafe condition on these products.

Final rule.

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:

2011-24-03 Bombardier, Inc.: Amendment 39-16867. Docket No. FAA- 2011-0720; Directorate Identifier 2010-NM-252-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective January 3, 2012.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes, certificated in any category, having serial numbers 4001 and subsequent.

Subject

(d) Air Transport Association (ATA) of America Code 32: Landing Gear.

Reason

(e) The mandatory continuing airworthiness information (MCAI) states:
There has been one reported incident where the main landing gear (MLG) failed to extend during testing of the MLG alternate release system. Investigation revealed that the door release lever bushing was worn, causing an increase in the lateral movement of the release cable system. An increase in free-play within the release cable system would cause additional wear to the door release lever bushing and may lead to the turnbuckle fouling against the nacelle frame. The bushing wear at the door release lever and turnbuckle fouling could cause a failure in the alternate release system, preventing the landing gear from extending in the case of a failure of the normal MLG extension/retraction system.
* * * * *
The unsafe condition is loss of control during landing.

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.

Actions

(g) Within 30 days after the effective date of this AD, revise the maintenance program by incorporating Task 323400-203 specified in Bombardier Temporary Revision (TR) MRB-46, dated February 4, 2010, to Section 1-32, Systems/Powerplant Maintenance

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Program, of the Maintenance Review Board (MRB) Report Part 1, of the Bombardier Q400 Dash 8 Maintenance Requirements Manual, PSM 1-84-7. The initial compliance time for the actions specified in Bombardier TR MRB-46, dated February 4, 2010, is within 6,000 flight hours after the effective date of this AD. Thereafter, operate the airplane according to the procedures and compliance times in Bombardier TR MRB-46, dated February 4, 2010.

Note 1: The revision required by paragraph (g) of this AD may be done by inserting a copy of Bombardier TR MRB-46, dated February 4, 2010, into Section 1-32, Systems/Powerplant Maintenance Program, of the Maintenance Review Board (MRB) Report Part 1, of the Bombardier Q400 Dash 8 MaintenanceRequirements Manual, PSM 1-84-7. When Bombardier TR MRB-46, dated February 4, 2010, has been included in general revision of the Bombardier Q400 Dash 8 Maintenance Requirements Manual, the Bombardier Q400 Dash 8 Maintenance Requirements Manual may be removed from Bombardier TR MRB-46, dated February 4, 2010, provided that the relevant information in the general revision is identical to that in Bombardier TR MRB-46, dated February 4, 2010.

No Alternative Actions, Intervals, and/or Critical Design Configuration Control Limitations (CDCCLs)

(h) After accomplishing the revision required by paragraph (g) of this AD, no alternative actions (e.g., inspections), intervals, and/or CDCCLs may be used unless the actions, intervals, and/or CDCCLs are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (i) 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

(i) 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, 1600 Stewart Avenue, Suite 410, Westbury, NY 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

(j) Refer to MCAI Canadian Airworthiness Directive CF-2010-26, dated August 17, 2010; and Bombardier Temporary Revision MRB-46, dated February 4, 2010, to Section 1-32, Systems/Powerplant Maintenance Program, of the Maintenance Review Board Report Part 1, of the Bombardier Q400 Dash 8 Maintenance Requirements Manual, PSM 1-84-7; for related information.

Material Incorporated by Reference

(k) You must use Bombardier Temporary Revision MRB-46, dated February 4, 2010, to Section 1-32, Systems/Powerplant Maintenance Program, of the Maintenance Review Board Report Part 1, of the Bombardier Q400 Dash 8 Maintenance Requirements Manual,PSM 1-84-7, 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., 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.
(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.
(4) 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 NARA, call (202) 741-6030, or goto: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

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 August 1, 2011 (76 FR 45713). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

There has been one reported incident where the main landing gear (MLG) failed to extend during testing of the MLG alternate release system. Investigation revealed that the door release lever bushing was worn, causing an increase in the lateral movement of the release cable system. An increase in free-play within the release cable system would cause additional wear to the door release lever bushing and may lead to the turnbuckle fouling against the nacelle frame. The bushing wear at the door release lever and turnbuckle fouling could cause a failure in the alternate release system, preventing the landing gear from extending inthe case of a failure of the normal MLG extension/retraction system.
This [Transport Canada Civil Aviation] directive is to mandate the incorporation of a new maintenance task to prevent excessive free-play of the turnbuckle and cable within the alternate release system.

The unsafe condition is loss of control during landing. 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 considered the comment received.

Request To Refer to Revision Incorporating Temporary Revision

Horizon Air Industries, Inc. (the commenter) requested that we revise paragraph (g) of the NPRM (76 FR 45713, August 1, 2011) to reference Revision 7, dated June 5, 2010, of the Bombardier Q400 Dash 8 Maintenance Requirements Manual (MRM), PSM 1-84-7, instead of Bombardier Temporary Revision (TR) MRB-46, dated February 4, 2010, to Section 1-32, Systems/Powerplant Maintenance Program, of the Maintenance Review Board (MRB) Report Part 1, of the Bombardier Q400 Dash 8 MRM, PSM 1-84-7. The commenter explained that this TR was removed from this MRM by Revision 7 of this MRM; therefore, this TR does not exist. The commenter reasoned that referencing Bombardier TR MRB-46 in the final rule will force operators to request an alternative method of

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compliance to use Revision 7 of this MRM, because this TR is no longer included in this MRM. The commenter suggested that, if the AD must reference the same document as Canadian AD CF-2010-26, dated August 17, 2010, then a paragraph needs to be added to the final rule allowing operators to remove this TR once it is incorporated into the manual by the general revision.
We agree that operators should be allowed to remove Bombardier TR MRB-46 once it is included in the general revision of the Bombardier MRM. Therefore, we have revised this final rule to add a note following paragraph (g) of this final rule toallow operators to remove Bombardier TR MRB-46, dated February 4, 2010, once it has been included in the general revisions of the Bombardier Q400 Dash 8 MRM. We have revised the final rule and re-identified subsequent notes accordingly.

Conclusion

We reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.

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 required different actions in this AD from those in the MCAI in order to follow our FAA policies. Any such differences are highlighted in a NOTE within the AD.

Costs of Compliance

We estimate that this AD will affect 65 products of U.S. registry. We also estimate that it will take about 1 work-hour per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $5,525, or $85 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 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.

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 (76 FR 45713, August 1, 2011), 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.