Airworthiness Directives; Eurocopter France Helicopters
We are superseding an existing emergency airworthiness directive (EAD) for Eurocopter France (Eurocopter) Model AS350B3 helicopters with certain part-numbered laminated half-bearings (bearings) and tail rotor (T/R) blades installed. The existing EAD currently requires installing two placards and revising the Rotorcraft Flight Manual (RFM). The EAD also requires certain checks and inspecting and replacing, if necessary, all four bearings. Finally, the EAD requires a one-time removal and inspection of the bearings, and replacing the bearings if necessary. Since we issued that EAD, we have determined that newly-designed helicopters with other part-numbered T/R blades may be affected by this unsafe condition and that the requirements should allow the bearing removal and inspection to be performed before the last flight of the day. This superseding AD removes the bearing and T/R blade part numbers (P/N) from the applicability paragraph and clarifies when the bearing removal and inspection is required. The actions are intended to prevent vibration due to a failed bearing, failure of the T/R, and subsequent loss of control of the helicopter.