Airworthiness Directive · Amendment 39-16189 · Turbomeca Arriel 2B and 2B1 Turboshaft Engines
Turbomeca Arriel 2B and 2B1 Turboshaft Engines
Superseded. A later AD replaced this one: AD 2012-03-11. Comply with the one in force.
This AD applies to Turbomeca Arriel 2B and 2B1 turboshaft engines that have not incorporated Modification TU 147. These engines are installed on, but not limited to, Eurocopter AS 350 B3 and EC 130 B4 helicopters.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
Unless already done, do the following actions.
(1) Within 550 engine flight hours from the effective date of this AD, check the transmissible torque between the low-pressure (LP) pump impeller and the high-pressure (HP) pump shaft of the HP/LP pump metering unit (HMU). Use paragraph 2 of the Instructions to be Incorporated of Turbomeca Mandatory Service Bulletin No. A292 73 2830, Version B, dated July 10, 2009, to do the check.
(2) If the check is compliant, apply the nominal tightening torque to the screw of the LP pump impeller.
(3) If the check is not compliant, replace the HP/LP pump HMU with a unit that has not incorporated Modification TU 147 but has passed the check, or with a unit that has incorporated Modification TU 147.
This AD differs from the MCAI and/or service information as follows:
(1) The MCAI requires the checking of the transmissible torque between the LP pump impeller and the HP pump shaft within 550 engine flight hours from the effective date of the AD, but no later than June 30, 2010.
(2) This AD requires the checking of the transmissible torque between the LP pump impeller and the HP pump shaft within 550 engine flight hours from the effective date 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.
