AD 2020-21-15 Airworthiness Directives; Airbus Helicopters

This AD becomes effective December 7, 2020.

(1) The Manager, Rotorcraft Standards Branch, FAA, may approve AMOCs for this AD. Send your proposal to: Rao Edupuganti, Aviation Safety Engineer, Regulations and Policy Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email 9-ASW-FTW-AMOC-Requests@faa.gov. (2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, the FAA suggests that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office, before operating any aircraft complying with this AD through an AMOC.

The subject of this AD is addressed in European Union Aviation Safety Agency (EASA) AD No. 2019-0165-E, dated July 12, 2019. You may view the EASA AD on the internet at https://www.regulations.gov in Docket No. FAA-2020-0618.

(1) Within 55 hours time-in-service or 5 months, whichever occurs first: (i) Open the TGB oil filter plug cover (cover) identified as “b” in Detail “A” and Detail “B” in Figure 1 of Airbus Helicopters Emergency Alert Service Bulletin (EASB) No. 65.00.19 or Airbus Helicopters EASB No. 65A008, both Revision 0 and dated July 10, 2019 (EASB 65.00.19 or EASB 65A008), as applicable to your model helicopter, by removing any lockwire, opening the cover (b), and removing the strainer (e) using a screwdriver. Remove the TGB oil filter plug (plug) identified as “h” in Detail “B” in Figure 1 of EASB 65.00.19 or EASB 65A008, as applicable to your model helicopter, by removing the sealing compound at the base of the plug (h), marking the base of the plug (h) and the TGB housing (c), and removing and cleaning the plug (h) and the exterior surface of the TGB housing (c) surrounding the plug (h) installation area. (ii) Using an adjustable or fixed head borescope with a 6 mm or larger diameter camera probe, inspect for operating oil (oil) retention and visibility of the two T holes in the TGB oil housing recess (housing recess) (towards the rear of the helicopter) identified as “g” in Section C-C in Figure 2 of EASB 65.00.19 or EASB 65A008, as applicable to your model helicopter. (A) If there is any oil retention in the housing recess (g) and the two T holes are not completely visible as shown in photo 1, in the Accomplishment Instructions, paragraph 3.B.2.b., of EASB 65.00.19 or EASB 65A008, as applicable to your model helicopter, before further flight, remove the TGB control rod and inspect for and remove any foreign objects in the TGB oil duct (oil duct) identified as “k” in Detail “D” of Figure 2 of EASB 65.00.19 or EASB 65A008, as applicable to your model helicopter. (B) With all of the oil drained from the housing recess (g), inspect for oil retention and visibility of the two T holes in the housing recess (g) as required by paragraph (e)(1)(ii) of this AD. ( 1 ) If there is any oil retention in the housing recess (g) and the two T holes are not completely visible, before further flight, replace the TGB. ( 2 ) If there is no oil retention in the housing recess (g) and the two T holes are completely visible, before further flight: ( i ) Inspect for any foreign objects in the oil duct identified as “k” in Section EE of Figure 3 of EASB 65.00.19 or EASB 65A008, as applicable to your model helicopter. If there is any foreign object, before further flight, remove each foreign object. ( ii ) Inspect for oil flow at the end of the oil duct (k) BTP (q) cover by following the procedures in the second step through the sixth step, inclusive, of the Accomplishment Instructions, paragraph 3.B.3.b., of EASB 65.00.19 or EASB 65A008, as applicable to your model helicopter. ( iii ) If the oil does not flow at the end of the oil duct (k) BTP (q) cover, before further flight, replace the TGB. ( iv ) If the oil flows at the end of the oil duct (k) BTP (q) cover, before further flight, remove from service the TGB control rod bearing. (2) As of the effective date of this AD, do not install a TGB on any helicopter unless, with the non-installed TGB in a level position using shims, the requirements of paragraph (e)(1) of this AD have been accomplished. Unless already done, installation of a new TGB control rod bearing is also required. Accomplishment Instructions, paragraph 3.B.6., of EASB 65.00.19 and EASB 65A008, as applicable to your model helicopter, contain information pertaining to inspecting a non-installed TGB. A TGB with a log card entry showing it has passed the requirements in the Accomplishment Instructions, paragraph 3.B.6., of EASB 65.00.19 and EASB 65A008, as applicable to your model helicopter, is acceptable for compliance with this paragraph.

This AD defines the unsafe condition as obstruction of the oil duct of the tail rotor gearbox (TGB) control bearing. This condition could result in a lack of lubrication on the TGB control bearing, which could affect the correct operation of the TGB, and subsequent reduced control of the helicopter.