AD/Ecureuil/119 Engine Controls Twist Grip Assembly (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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.

Eurocopter AS 350 (Ecureuil) Series Helicopters

AD/ECUREUIL/119 Engine Controls - Twist Grip Assembly 7/2006

Applicability:

Eurocopter EC 130 B4 helicopters equipped with a twist grip assembly, part number:

- 350A27520900 or 350A27520901 or 350A27520902 or 350A27520903, with a serial number below 64, on the pilot’s side; or

- 350A27521201, with a serial number below 67, on the co-pilot’s side.

Requirement:

The following measures are rendered mandatory as from the effective date of this AD.

1.    Check the bonding between the drive tube and the control pinion of the pilot and co-pilot collective lever twist grip assembly, by applying a load to the twist grip, in accordance with paragraphs 2.B.1 and 2.B.2 of EUROCOPTER EC 130 Alert Service Bulletin (ASB) No. 76A001, date 9 February 2006 or later DGAC approved revision.

2.    If the twist grip turns when applying the load to the twist grip, replace the corresponding collective lever.

3.    Comply with the instructions specified in paragraph 2.8.3 of the Eurocopter ASB No. 76A001, or later DGAC approved revision.

Note:  EASA AD 2006-0079 dated 3 April 2006 refers.

Compliance:

1.    No later than within 110 flying hours or within 4 months, whichever occurs first after the effective date of this AD.

2.    Before further flight after complying with Requirement 1 of this AD.

3.    Before installation on a helicopter, of a twist grip assembly covered by this AD and held as spares.

This Airworthiness Directive becomes effective on 6 July 2006.

Background:

This is issued following a case experienced during an autorotation training procedure during which the engine remained at idle rating although the twist grip had been turned back to the flight position.

Analysis has revealed failure of the twist grip drive tube and control pinion bonded attachment due to non-compliant surface preparation.

James Coyne
Delegate of the Civil Aviation Safety Authority

24 May 2006