Airworthiness Directive · Amendment 39-12074 · Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters
Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters
Model S-76A, S-76B, and S-76C helicopters up to and including serial number 760513 with positioning rod assembly (rod assembly), part number (P/N) 1945E-31A or 2071-31, or side brace rod end (rod end), P/N 1945E-235 or 2071-235, installed, certificated in any category.
This amendment adopts a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, S-76B, and S-76C helicopters. This AD requires initial and repetitive inspections of the main landing gear positioning rod assembly (rod assembly) and the side brace rod end (rod end) for corrosion. If any corrosion is found, this AD requires replacing any part that is corroded with an airworthy part before further flight. This amendment is prompted by a landing gear collapse caused by corrosion due to dissimilar metals in the landing gear rod end. The actions specified in this AD are intended to detect corrosion of the threaded joint in the rod assembly to prevent a collapse of the landing gear, and subsequent loss of control of the helicopter during landing.
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.
