AD 2011-18-18

(a) This airworthiness directive (AD) becomes effective October 14, 2011.

(b) None.

(c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes; certificated in any category; serial numbers 4001 through 4305 inclusive.

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

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

Several operators have reported pitch oscillations and/or elevator asymmetry caution lights illumination when flying with the autopilot engaged. Investigations revealed that loose rivets in the torque tube assemblies caused relative motion between the crank arms and torque tubes.

Loose rivets could result in excessive wear and subsequent significant backlash in the driving crank arms. This condition, if left uncorrected, will progressively get worse and degrade the controllability of the aeroplane.

(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.

(g) At the applicable times identified in paragraphs (g)(1) and (g)(2) of this AD, do an inspection to determine the part numbers of the left and right elevator torque tubes, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision ‘D,' dated September 22, 2010. A review of airplane maintenance records is acceptable in lieu of this inspection if the part numbers of the left and right elevator torque tubes can be conclusively determined from that review.

(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, but before the accumulation of 10,000 total flight hours.

(h) If, as a result of the inspection required by paragraph (g) of this AD, any left elevator torque tube has part number (P/N) 82760709-009, at the applicable time in paragraph (g)(1) or (g)(2) of this AD, do the actions in paragraph (h)(1) or (h)(2) of this AD.

(1) Replace the elevator torque tube with a new elevator torque tube having P/N 82760709-011, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision ‘D,' dated September 22, 2010.

(2) Replace the rivets in each elevator torque tube assembly with Hi Lite pins having P/N B0206001AG8 and collars having P/N HST1070CY, and re-identify the elevator torque tube assembly having P/N 82760709-009, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision ‘D,' dated September 22, 2010.

(i) If, as a result of the inspection required by paragraph (g) of this AD, any right elevator torque tube has P/N 82760757-009, at the applicable time in paragraph (g)(1) or (g)(2) of this AD, do the actions in paragraph (i)(1) or (i)(2) of this AD.

(1) Replace the elevator torque tube with a new elevator torque tube having P/N 82760757-011, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision ‘D,' dated September 22, 2010.

(2) Replace the rivets in each elevator torque tube assembly with Hi Lite pins having P/N B0206001AG8 and collars having P/N HST1070CY, and re-identify the elevator torque tube assembly having P/N 82760757-009, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-27-50, Revision ‘D,' dated September 22, 2010.

(j) Actions done before the effective date of this AD, in accordance with the service bulletins listed in table 1 of this AD, are considered acceptable for compliance with the corresponding action specified in this AD.

(k) As of the effective date of this AD, no person may install on any airplane an elevator torque tube assembly having P/N 82760709-009 or 82760757-009.

Note 1:

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

(l) 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, 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.

(m) Refer to MCAI Canadian Airworthiness Directive CF-2010-27, dated August 20, 2010; and Bombardier Service Bulletin 84-27-50, Revision ‘D,' dated September 22, 2010; for related information.

(n) You must use Bombardier Service Bulletin 84-27-50, Revision ‘D,' dated September 22, 2010, 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; e-mail 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 go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.