Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD) applicable to Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. This action requires, before further flight, revising the life limits for certain parts and replacing each part that has exceeded its life limit. The AD also requires revising the applicable component history cards or equivalent records and the Airworthiness Limitations Schedule of the BHTC Model 407 maintenance manual to reflect these new life limits. This amendment is prompted by an engineering evaluation of additional flight test data, which resulted in redefining the service life for certain parts and revising the Airworthiness Limitations Schedule. The actions specified in this AD are intended to prevent a fatigue failure of certain parts that may have exceeded revised life limits and subsequent loss of control of the helicopter.