Airworthiness Directive · Amendment 39-12134 · Sikorsky Aircraft Corporation Model S-76B and S-76C Helicopters
Sikorsky Aircraft Corporation Model S-76B and S-76C Helicopters
Model S-76B and S-76C helicopters, with main rotor shaft assembly (shaft), part number (P/N) 76351-09630 all dash numbers, serial number (S/N) C213-00274, C213-00275, C213-00276, C213-00277, C213-00278, C213-00279, C213-00280, C213-00282, C213- 00292, C213-00294, C213-00295, C213-00296, C213-00297, C213-00299, and C213-00300, installed, certificated in any category.
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2001-03-51, which was sent previously to all known U.S. owners and operators of Sikorsky Aircraft Corporation (Sikorsky) Model S-76B and S-76C helicopters by individual letters. This AD requires, for certain main rotor shafts, initial and recurring fluorescent penetrant inspections. Replacing each affected main rotor shaft (shaft) on or before reaching 1,000 hours time-in- service (TIS) is also required. This amendment is prompted by four reports of shaft cracks. The actions specified by this AD are intended to prevent failure of the shaft and subsequent loss of control of the helicopter.
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.
