Airworthiness Directive · Amendment 39-21668 · Tail rotor drive shaft
Leonardo S.p.a. Helicopters
This AD applies to Leonardo S.p.a. Model A119 and AW119 MKII helicopters, certificated in any category, with 90-degree tail rotor gearbox (TGB) part number (P/N) 109-0440-06-101 or 109-0440-06-105, and with TGB shaft P/N 109-0443-03-107 having a serial number (S/N) listed in Table 1 of Leonardo Helicopters Alert Service Bulletin No. 119-090, Revision A, dated September 14, 2020 (ASB 119-090), installed.
Note 1 to paragraph (c): A TGB shaft is also referred to as a mast gear assembly.
The FAA is superseding Airworthiness Directive (AD) 2020-19-11 for certain Leonardo S.p.a. Model A119 and AW119 MKII helicopters. AD 2020-19-11 required repetitive borescope inspections of the 90-degree tail rotor gearbox (TGB) and depending on the inspection results, removing the TGB from service. This AD was prompted by the determination that additional parts may be susceptible to the unsafe condition. This AD retains the inspection requirements of AD 2020-19-11, and revises the compliance time and applicability. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 25 hours time-in-service (TIS) or 3 months, whichever occurs first after the effective date of this AD, and thereafter at intervals not to exceed 6 months, borescope inspect the entire internal surface of the TGB shaft for corrosion. Refer to Detail A of Figure 1 of ASB 119-090, for a depiction of the entry point for the borescope. If there is corrosion, before further flight, remove the TGB from service.
(2) As of the effective date of this AD, do not install on any helicopter any TGB P/N 109-0440-06-101 or 109-0440-06-105 that has TGB shaft P/N 109-0443-03-107 having an S/N listed in Table 1 of ASB 119-090, unless the actions required by paragraph (g)(1) of this AD have been accomplished.
