Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Helicopters (Airbus) Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters. This proposed AD was prompted by a manufacturer assessment that determined additional actions are necessary to improve particle detection for main gearboxes (MGBs) with certain planet gear bearings installed. This proposed AD would require repetitively inspecting the MGB bevel wheel for the presence of particles, repetitively inspecting the MGB magnetic plug for particles, and prohibit installing an affected MGB unless certain requirements are met. These actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference. The FAA is proposing this AD to address the unsafe condition on these products.