Airworthiness Directives; Eurocopter France Model AS 332C, AS 332L, AS 332L1, and AS 332L2 Helicopters

This amendment adopts a new airworthiness directive (AD) that is applicable to Eurocopter France (ECF) Model AS 332C, AS 332L, AS 332L1, and AS 332L2 helicopters. This action requires inserting instructions into the Model AS 332C, AS 332L, AS 332L1, and AS 332L2 Rotorcraft Flight Manuals (RFMs) regarding actions to take if either the ``OVSP 1'' or ``OVSP 2'' amber warning light illuminates. This action also requires, for the Model AS 332C, AS 332L, and AS 332L1 helicopters, measuring the vibration levels of the engine-to-main gearbox (MGB) shaft, inspecting the torque on the MGB coupling bolts, and conducting an engine-to-MGB coupling 23,000 revolutions per minute (RPM) input check. This amendment is prompted by an accident involving a Model AS 332L1 helicopter in which the helicopter experienced an engine overspeed resulting in failure of both engines. The actions specified in this AD are intended to prevent failure of the rotor drive engine-to-MGB coupling, which, if undetected, could result in an engine overspeed leading to an uncontained engine turbine wheel burst and subsequent loss of control of the helicopter.