Airworthiness Directive · Amendment 39-18389 · Turbomeca S.A. Turboshaft Engines
Turbomeca S.A. Turboshaft Engines
This AD applies to Turbomeca S.A. ARRIEL 2C, 2C1, 2C2, 2S1, and 2S2 turboshaft engines with modification TU34 or TU34A installed.
We are adopting a new airworthiness directive (AD) for all Turbomeca S.A. ARRIEL 2C, 2C1, 2C2, 2S1, and 2S2 turboshaft engines with modification TU34 or TU34A installed. This AD requires inspecting the torque conformation box (TCB) for correct resistance values and removing TCBs that fail inspection before further flight. This AD was prompted by TCB failures. We are issuing this AD to prevent failure of the TCB, loss of engine thrust control, and damage to the helicopter.
(1) Within 600 engine flight hours (EFHs) or 6 months after the effective date of this AD, whichever occurs first, check the resistance values on the TCB. Use Accomplishment Instructions, paragraph 2.3.2 of Turbomeca S.A. Mandatory Service Bulletin 292 72 2860, Version A, dated July 15, 2015, to do the inspection. Repeat this inspection every 600 EFHs since last inspection.
(2) Remove before further flight any TCB that fails the inspection required by paragraph (e)(1) of this AD.
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.
