Airworthiness Directive · Amendment 39-14795 · Turbomeca Arriel 2B Series Turboshaft Engines
Turbomeca Arriel 2B Series Turboshaft Engines
Superseded. A later AD replaced this one: AD 2007-10-07. Comply with the one in force.
This AD applies to Turbomeca Arriel 2B, 2B1, and 2B1A turboshaft engines. These engines are installed on, but not limited to, Eurocopter AS350B3 and EC130B4 helicopters.
The FAA is adopting a new airworthiness directive (AD) for Turbomeca Arriel 2B, 2B1, and 2B1A turboshaft engines. This AD requires visually inspecting the splines of the high-pressure (HP) pump drive gear shaft and coupling shaft assembly for wear. This AD results from reports of uncommanded in-flight shutdowns of engines. We are issuing this AD to detect wear on the splines of the HP pump drive gear shaft and coupling shaft assembly, which could interrupt the fuel flow and cause an uncommanded in-flight shutdown of the engine on a single- engine helicopter. The in-flight shutdown of the engine could result in a forced autorotation landing or accident.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
Perform an initial visual inspection of the splines of the coupling assembly and the HP pump drive gear shaft for wear. Use 2.A. through 2.C.(2) of the Instructions to be Incorporated of Turbomeca Mandatory Service Bulletin (MSB) No. 292 73 2812, Update No. 2, dated June 28, 2005, as follows:
(1) For hydraulic mechanical units (HMUs) that have accumulated 450 or more hours time-since-new (TSN) or time-since-overhaul (TSO) on the effective date of this AD, inspect within 50 hours after the effective date of this AD. Replace the HMU if worn beyond limits.
(2) For HMUs that have fewer than 450 hours TSN or TSO on the effective date of this AD, inspect after accumulating 450 hours TSN or TSO, but before accumulating 500 hours TSN or TSO. Replace the HMU if worn beyond limits.
Thereafter, perform a visual inspection of the splines of the coupling shaft assembly and the HP pump drive gear shaft for wear every time you remove or install the HMU. Use 2.A. through 2.C.(2) of the Instructions to be Incorporated of Turbomeca MSB No. 292 73 2812, Update No. 2, dated June 28, 2005. Replace the HMU and coupling shaft assembly if worn beyond limits.
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.
