Airworthiness Directive · Amendment 39-12710 · Enstrom Helicopter Corporation Model F-28, F-28A, F-28C, F-28F, 280, 280C, 280F, and 280FX Helicopters
Enstrom Helicopter Corporation Model F-28, F-28A, F-28C, F-28F, 280, 280C, 280F, and 280FX Helicopters
Model F-28, F-28A, F-28C, F-28F, 280, 280C, 280F, and 280FX helicopters, certificated in any category.
This amendment supersedes an existing airworthiness directive (AD) for Enstrom Helicopter Corporation (EHC) Model F-28, F-28A, F-28C, F-28F, 280, 280C, 280F, and 280FX helicopters. That AD currently requires determining the radius of the shaft fillet, performing certain visual and dye-penetrant inspections before further flight, and replacing certain main rotor transmissions. This amendment requires the same actions as the previous AD, adds additional main rotor gear box part numbers, and corrects various errors contained in the current AD. This amendment is prompted by a commenter who noted that two additional main rotor gear box part numbers should have been included in the AD. The actions specified by this AD are intended to prevent shaft failure 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.
