Airworthiness Directive · Amendment 39-21130 · Tail rotor system
Airbus Helicopters
Superseded. A later AD replaced this one: AD 2021-26-07. Comply with the one in force.
This AD applies to Airbus Helicopters Model EC120B helicopters, certificated in any category, all serial numbers.
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model EC120B helicopters. This AD was prompted by a report of recurrent loss of tightening torque on several attachment bolts of the tail rotor hub body. This AD requires repetitive inspections of the tail rotor hub body for cracks and applicable corrective actions if necessary, and repetitive replacement of the attachment bolts, washers, and nuts of the tail rotor hub body. The FAA is issuing this AD to address the unsafe condition on these products.
(1) For the purposes of this AD, an affected part is any tail rotor hub body part number C642A0100103.
(2) For the purposes of this AD, a serviceable part is any affected part that is new (not previously installed on any helicopter); or any affected part on which an inspection has been done as specified in the instructions of Airbus Helicopters Emergency Alert Service Bulletin 05A020, Revision 0, dated October 29, 2019, or Airbus Helicopters Emergency Alert Service Bulletin 05A020, Revision 1, dated November 8, 2019, and there were no cracks.
Within 15 hours time-in-service (TIS) or 7 days, whichever occurs first after the effective date of this AD: Inspect the affected part (as defined in paragraph (g)(1) of this AD) for cracking in accordance with the instructions of section 3.B.2 of Airbus Helicopters Emergency Alert Service Bulletin 05A020, Revision 1, dated November 8, 2019. Thereafter, repeat the inspection at intervals not to exceed 15 hours TIS.
(1) If, during any inspection required by paragraph (h) of this AD, there are any cracks, before next flight, replace the tail rotor hub body with a serviceable part (as defined in paragraph (g)(2) of this AD) and replace the bolts, washers, and nuts with new bolts, washers, and nuts, in accordance with the instructions of section 3.B.3 of Airbus Helicopters Emergency Alert Service Bulletin 05A020, Revision 1, dated November 8, 2019, and inspect the tail rotor splined flange for the conditions identified in figure 1 to paragraph (i)(1) of this AD and at the areas identified in figure 2 to paragraph (i)(1) of this AD in accordance with the instructions of section 1.E.2 of Airbus Helicopters Emergency Alert Service Bulletin 05A020, Revision 1, dated November 8, 2019.
Note 1 to paragraph (i)(1): You may refer to “Detailed Check—Splined Flange,” Task 64-21-00, 6-5, Airbus Aircraft Maintenance Manual (AMM) Version B, dated April 7, 2014, which pertains to the tail rotor splined flange inspection.
(2) If, during any inspection of the tail rotor splined flange required by paragraph (i)(1) of this AD, the condition of the part exceeds the criteria as specified in figure 1 to paragraph (i)(1) of this AD, before next flight, replace the tail rotor splined flange with an airworthy tail rotor splined flange in accordance with the instructions of section 3.B.4 of Airbus Helicopters Emergency Alert Service Bulletin 05A020, Revision 1, dated November 8, 2019.
Within the applicable compliance time specified in figure 3 to paragraph (j) of this AD, replace the attachment bolts, washers, and nuts of the tail rotor hub body with new bolts, washers, and nuts in accordance with the instructions of Airbus Helicopters Emergency Alert Service Bulletin 05A020, Revision 1, dated November 8, 2019. Thereafter, repeat the replacement of the bolts, washers, and nuts at intervals not to exceed 1,000 hours TIS.
As of the effective date of this AD, it is allowed to install on any helicopter an affected part, provided it is a serviceable part, as defined in paragraph (g) of this AD.
