AD/ARRIEL/25 Amdt 1 - Fuel Filter Drain Screw (Cth)

AIRWORTHINESS DIRECTIVE On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ARRIEL/25 and issues the following AD under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Turbomeca Turbine Engines - Arriel Series AD/ARRIEL/25 Amdt 1 Fuel Filter Drain Screw 10/2007

Applicability: Turbomeca ARRIEL 2S1 and ARRIEL 2S2 turboshaft engines that have a Hydromechanical Unit (HMU) installed that was manufactured before 8 December 2006 or repaired/overhauled by a Turbomeca approved repair centre before 8 December 2006. Requirement: Replace the fuel filter drain screw with a new one and tighten to an effective torque of 6.5 Nm in accordance with Turbomeca Mandatory Service Bulletin 292 73 2824 or later approved revisions.

Note: EASA AD 2007-0063 dated 08 March 2007 refers. Compliance: Unless already accomplished, within 30 HMU operating hours after the effective date of this AD. This Amendment becomes effective on 27 September 2007. Background: During assembly of the HMU it was discovered that the torque being applied to the screw was exceeding the material qualities of the screw. This could lead to failure of the screw allowing leakage of fuel potentially causing engine failure or fire.