AD/ARRIUS/7 Amdt 1 - High Pressure Turbine (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/ARRIUS/7 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 - Arrius Series AD/ARRIUS/7 Amdt 1 High Pressure Turbine 7/2005 TX

Applicability: Turbomeca ARRIUS 2F engines which are fitted to Eurocopter EC120B helicopters. Requirement: 1. Do not operate engines fitted with number 2 modules as listed in Alert Fax TURBOMECA 057/05/DSO/TM.

2. Engines may be returned to service following inspection/rework at a repair centre, or after module 2 replacement on site or in a workshop, or after inspection of the standard of the ferrule by applying deep servicing instructions on site.

Note: DGAC AD UF-2005-073R1 EASA approval No 2005-3868 dated 29 April 2005 refers. Compliance: From the effective date of this Directive. This Amendment becomes effective on 5 May 2005. Background: Following an accident involving an EC1 208, the initial investigation of the Arrius 2F engine showed that one HP blade was totally released from the HP disk. This blade was contained inside the containment ring.

The preliminary examination of the engine parts showed that the standard of one ferrule initiated a disturbance in the secondary air system used to cool the HP turbine.