Airworthiness Directive · Amendment 39-16586 · Tail rotor drive
Bell Helicopter Textron Canada Limited Model 427 Helicopters
This AD applies to Bell Helicopter Textron Canada Limited Model 427 helicopters, all serial numbers (SNs), certificated in any category.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued 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:
Unless already done, do the following actions:
(1) Applicable to SNs 56001 through 56073, and 56077: Within 30 days after April 14, 2011 (the effective date of this AD), inspect both sides of the hanger bracket, P/N 427-044-223-101, for cracks following Bell Helicopter Alert Service Bulletin No. 427-09-29, REV A, dated November 17, 2009.
(i) If no cracks are found during the inspection required by paragraph (f)(1) of this AD, before further flight, rework both sides of the hanger bracket, P/N 427-044-223-101, following Bell Helicopter Alert Service Bulletin No. 427-09-29, REV A, dated November 17, 2009.
(ii) If cracks are found during the inspection required by paragraph (f)(1) of this AD, before further flight, replace the hanger bracket, P/N 427-044-223-101, with a new hanger bracket, P/N 427-044-223-101, that has been reworked following Bell Helicopter Alert Service Bulletin No. 427-09-29, REV A, dated November 17, 2009.
(2) Applicable to all SNs: As of April 14, 2011 (the effective date of this AD), you may not install replacement tail rotor driveshaft hanger bracket, P/N 427-044-223-101, unless the bracket has been inspected and found free of cracks and has been reworked following Bell Helicopter Alert Service Bulletin No. 427-09-29, REV A, dated November 17, 2009.
Note: This AD differs from the MCAI and/or service information as follows: No differences.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
