Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Helicopters

We are superseding Airworthiness Directive (AD) 2003-05-03 for Bell Model 407 helicopters. AD 2003-05-03 required preflight checking and repetitively inspecting for a crack in certain tailbooms that have been redesigned, replacing the tailboom if there is a crack, modifying and re-identifying certain tailbooms, installing an improved horizontal stabilizer assembly, and assigning a 5,000 hour time-in-service (TIS) limit. This new AD retains the requirements of AD 2003-05-03 and requires additional inspection requirements. This AD was prompted by additional reports of cracked tailboom skins. The actions in this AD are intended to prevent separation of the tailboom and subsequent loss of control of the helicopter.