Airworthiness Directive · Amendment 39-9541 · Bell Helicopter Textron Canada Limited Helicopters
Bell Helicopter Textron Canada Limited Helicopters
This AD applies to Bell Helicopter Textron Canada Limited 206A, 206A-1 (OH-58A), 206B, 206B-1.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron, A Division of Textron Canada, Ltd., (BHTC) Model 206A and 206B helicopters, that currently requires an inspection of the main transmission input driveshaft assembly (driveshaft) at intervals of 300 hours time-in-service (TIS); the application of a zinc chromate primer inspection visual aid; and, daily visual checks of the driveshaft. This amendment requires inspections of the driveshaft at intervals of 300 hours TIS; the application of a self-adhesive temperature indicator visual inspection aid ; and, preflight visual owner/operator (pilot) checks of the driveshaft. This amendment is prompted by recent studies that indicate self-adhesive temperature indicators are a more reliable means of detecting overheat conditions on grease-lubricated couplings than the zinc chromate primers currently in use. The actions specified by this AD are intended to prevent failure of the driveshaft due to coupling wear or overheating, which could result in loss of power to the main rotor and a subsequent forced emergency 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.
