AD/Bell 407/36 Anti-drive Link Assembly (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bell Helicopter Textron Canada (BHTC) 407 Series Helicopters

AD/BELL 407/36 Anti-drive Link Assembly 7/2009 TX

Applicability:

Bell Helicopter Textron Canada (BHTC) Helicopter Models 407 with anti-drive link assembly Part Number (P/N) 406-010-432-101 with a serial number (S/N) prefix TI or TIFS.

Models affected: Model 407 - S/N 53000 through 53887, 53890 through 53916, 53918, 53920, 53921, 53923 through 53926, and 53928.

Requirement:

Perform a one time inspection and if required, rectification, of the anti-drive link assembly P/N 406-010-432-101 to ensure that bearing P/N 406-310-403-101 is correctly staked in the link assembly in accordance with BHTC Alert Service Bulletin 407-09-87, dated 27 March 2009, or later approved revision.

Note:  Transport Canada AD CF-2009-14 dated 15 April 2009 refers.

Compliance:

Within the next 10 flight hours, but no later than 30 days from the effective day of this AD, unless already accomplished.

This Airworthiness Directive becomes effective on 6 May 2009.

Background:

During a pre-flight check it was observed that the swash plate link assembly bearing P/N 406-310-403-101 had moved in the lever race making contact with the swash plate support.  Further investigation has revealed that the bearing had not been staked correctly during manufacture.

This situation, if not corrected, could lead to loss of control of the helicopter.

James Coyne
Delegate of the Civil Aviation Safety Authority

30 April 2009