Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Leonardo S.p.a. (Leonardo) Model A119 and AW119MKII helicopters. This proposed AD would require repetitive borescope inspections of the tail rotor gearbox (TGB) and depending on the inspection results, removing the TGB from service. This proposed AD was prompted by reports of corrosion on the internal surface of the 90- degree TGB output shaft. The actions of this proposed AD are intended to address an unsafe condition on these products.