Summary
We propose to adopt a new airworthiness directive (AD) for Bell Model 206L-4 and 407 helicopters. This proposed AD would require replacing or reworking certain aft bearing caps. This proposed AD is prompted by the manufacture of certain freewheel aft bearing caps without a lubrication channel to allow oil flow into the aft bearing support assembly. The proposed actions are intended to prevent failure of the freewheel unit and subsequent loss of control of the helicopter.