Airworthiness Directive · Amendment 39-13809 · Pratt & Whitney Canada PT6B-36A and PT6B-36B Turboshaft Engines
Pratt & Whitney Canada PT6B-36A and PT6B-36B Turboshaft Engines
This AD applies to Pratt & Whitney Canada (PWC) PT6B-36A and PT6B-36B turboshaft engines with compressor rear hubs, part number (P/N) 3018111 installed. These engines are installed on, but not limited to, Sikorsky S-76B helicopters.
The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney Canada (PWC) PT6B-36A and PT6B-36B turboshaft engines with compressor rear hubs, part number (P/N) 3018111 installed. This AD requires reviewing, and correcting if necessary the critical part record for compressor rear hubs, P/N 3018111. This AD also requires removing compressor rear hubs from service that exceed the published part life limit, before further flight. This AD results from the discovery of a compressor rear hub, P/N 3018111, that exceeded the published life limit. This occurred because the operator used an incorrect life limit calculation contained in a PWC Service Bulletin. We are issuing this AD to prevent uncontained failure of the compressor rear hub and damage to the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
(f) Within 30 days or at the next engine shop visit, whichever occurs first after the effective date of this AD, do the following:
(1) Using the Flight Count Factor of 3, review and correct the critical part record for compressor rear hubs, P/N 3018111. Use paragraph 3 of the Accomplishment Instructions of PWC Service Bulletin (SB) No. PT6B-72-11002, Revision 8, dated June 11, 2003, to do this.
(2) Remove the compressor rear hub from service before further flight, if its life limit is found to be at or higher than the published life limit in PWC SB No. PT6B-72-11002, Revision 8, dated June 11, 2003.
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.
