Airworthiness Directive · Amendment 39-21698 · Main rotor blades
Leonardo S.p.a. Helicopters
This AD applies to Leonardo S.p.a. Model AB139 and AW139 helicopters, certificated in any category, with a main rotor blade (MRB) that has less than 1,200 total hours time-in-service (TIS) and has part number 3G6210A00131 with any serial number listed in Table 1 of Leonardo Helicopters Alert Service Bulletin No. 139-520, dated April 26, 2018 (ASB 139-520), installed.
The FAA is adopting a new airworthiness directive (AD) for Leonardo S.p.a. Model AB139 and AW139 helicopters with certain main rotor blades installed. This AD was prompted by a report of an in- flight loss of a main rotor blade (MRB) tip cap. This AD requires inspecting the MRB tip cap for disbonding. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 50 hours TIS after the effective date of this AD, using a tap hammer or equivalent, tap inspect each MRB tip cap for disbonding in the area depicted in Figure 1 of ASB 139-520.
(i) If there is no disbonding, tap inspect each MRB tip cap as required by paragraph (g)(1) of this AD at intervals not to exceed 50 hours TIS.
(ii) If there is any disbonding that does not exceed the limits specified in Annex A, paragraphs 2.3 and 2.4 of ASB 139-520, tap inspect the MRB tip cap as required by paragraph (g)(1) of this AD at intervals not to exceed 10 hours TIS.
(iii) If there is any disbonding that exceeds the limits specified in Annex A, paragraphs 2.3 and 2.4 of ASB 139-520, remove the MRB from service before further flight.
(2) Accumulation of 1,200 total hours TIS on the affected part without findings of any disbonded area or with findings of any disbonded area that is within the permitted limits specified in Annex A, paragraphs 2.3 and 2.4 of ASB 139-520, constitutes terminating action for the repetitive inspections required by paragraphs (g)(1)(i) and (ii) of this AD.
(3) As of effective date of this AD, do not install any MRB that is identified in paragraph (c) 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
