Airworthiness Directive · Amendment 39-21245 · Rotor drive- gearbox
Leonardo S.p.a. Helicopters
This AD applies to Leonardo S.p.a. Model AB139 and AW139 helicopters, certified in any category, with main gearbox (MGB) input module part number (P/N) 3K6320A00135 with serial number (S/N) KHI-200 or P/N 3K6320A00136 with an S/N listed in Table 1 to this paragraph installed.
The FAA is adopting a new airworthiness directive (AD) for Leonardo S.p.a. (Leonardo) Model AB139 and AW139 helicopters. This AD requires removing certain main gearbox (MGB) input modules from service. This AD was prompted by the discovery that a batch of duplex bearings, which are installed on the MGB input modules, are defective. The actions of this AD are intended to address an unsafe condition on these products.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) If the P/N and S/N of both MGB input modules are listed in paragraph (a) of this AD, within 300 hours time-in-service (TIS), remove from service each MGB input module.
(2) If the P/N and S/N of only one MGB input module are listed in paragraph (a) of this AD, within 1,200 hours TIS, remove from service that MGB input module.
(3) After the effective date of this AD, do not install an MGB input module with a P/N and S/N listed in paragraph (a) of this AD on any helicopter.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
