Airworthiness Directive · Amendment 39-19631 · Main rotor drive system
Bell Helicopter Textron Canada Limited Helicopters
This AD applies to Bell Model 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, and 407 helicopters, certificated in any category.
We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 206A, 206B, 206L, 206L- 1, 206L-3, 206L-4, and 407 helicopters. This AD requires inspecting and cleaning the oil supply restrictor (restrictor) to the freewheel assembly. This AD was prompted by reports of a blocked oil line restrictor in the freewheel lubrication system. The actions of this AD are intended to address an unsafe condition on these products.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
Within 100 hours time-in-service:
(1) For all helicopters:
(i) Inspect the oil line restrictor for blockage. If there is any blockage in the restrictor, before further flight, inspect the freewheel assembly clutch, inner shaft, outer shaft, forward seal, cap, and bearings for wear, corrosion, nicks, scratches, and cracks; the splines for wear, cracks, chipped teeth, and broken teeth; the housing for flaking; and for free rotation and engagement of the clutch and bearing. If there is any damage that exceeds allowable limits or if the clutch or bearing does not engage or freely rotate, before further flight, repair or replace the freewheel assembly.
(ii) Clean, inspect, and flush each removed fitting, restrictor, tube, hose, and filter with dry cleaning solvent. Do not approve for return to service until each restrictor is free from contamination.
(2) For Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters with a reducer, replace the reducer with a filter part number 50-075-1.
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.
