AD 2001-25-06
Effective 01/04/2002 · Published 12/20/2001
Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76B and S-76C Helicopters
Summary
This amendment adopts a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-76B and S-76C helicopters. This action requires modifying the electrical power distribution system to change the source of the 28 volts supplied to Nos. 1 and 2 attitude and heading reference (AHRS) WARN circuits. This amendment is prompted by a ground test simulating loss of the essential bus by pulling bot…