Airworthiness Directive · Amendment 39-18493 · Turbomeca S.A. Turboshaft Engines
Turbomeca S.A. Turboshaft Engines
This AD applies to all Turbomeca S.A. Arriel 2E turboshaft engines that have a pre-TU 193 adjusted high-pressure/low-pressure (HP/LP) pump and metering valve assembly, installed.
We are adopting a new airworthiness directive (AD) for all Turbomeca S.A. Arriel 2E turboshaft engines. This AD requires removing the pre-TU 193 adjusted high-pressure/low-pressure pump and metering valve assembly and replacing it with a part that is eligible for installation. This AD also requires replacing the constant delta- pressure (delta-P) diaphragm of the fuel metering valve. This AD was prompted by reports of fuel flow non-conformities found during acceptance tests of Arriel 2E hydro-mechanical metering units (HMUs). We are issuing this AD to prevent failure of the delta-P diaphragm, which could result in an uncommanded in-flight shutdown and damage to the helicopter.
(1) Prior to exceeding 880 operating hours since new on the adjusted HP/LP pump and metering valve assembly or within 50 operating hours after the effective date of this AD, whichever occurs later:
(i) Remove from service the adjusted HP/LP pump and metering valve assembly and replace with a part that is eligible for installation, and
(ii) replace the constant delta-P diaphragm of the fuel metering valve.
(2) Reserved.
After the effective date of this AD, do not install into any engine any pre-TU 193 adjusted HP/LP pump and metering valve assembly, nor install onto any helicopter any engine that has a pre-TU 193 adjusted HP/LP pump and metering valve assembly.
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.
Engines
