Airworthiness Directive · Amendment 39-21708 · Landing gear system
Leonardo S.p.a. Helicopters
This AD applies to Leonardo S.p.a. Model AB412 and AB412 EP helicopters, certificated in any category, with a high skid landing gear assembly part number (P/N) 412-050-012-(XXX), 412-050-014-(XXX), 412-050-050-(XXX), or 412-050-059-(XXX), where “(XXX)” represents any 3-digit combination, installed.
The FAA is adopting a new airworthiness directive (AD) for certain Leonardo S.p.a. Model AB412 and AB412 EP helicopters. This AD was prompted by the results of a fatigue review. This AD requires establishing a life limit for certain part-numbered high landing gear aft crosstubes. The FAA is issuing this AD to address the unsafe condition on these products.
For high landing gear aft crosstube P/Ns 412-050-010-101, 412-050-010-107, 412-050-010-111, and 412-050-045-107:
(1) Before further flight after the effective date of this AD, determine the total number of landings. For purposes of this AD, a landing is counted anytime a helicopter lifts off into the air and then lands again regardless of the duration of the landing and regardless of whether the engine is shutdown. If the total number of landings cannot be determined, multiply the total hours time-in-service accumulated by the high landing gear aft crosstube by 4. Remove any high landing gear aft crosstube from service that has accumulated or exceeded 10,000 total landings.
(2) Create a component history card or equivalent record to establish a life limit of 10,000 total landings.
(3) Thereafter, remove any high landing gear aft crosstube from service before accumulating 10,000 total landings.
