AD/EC 120/9 Amdt 1 Collective Pitch Lever Friction Mechanism (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/EC 120/9 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.

Eurocopter EC 120 Series Helicopters

AD/EC 120/9 Amdt 1 Collective Pitch Lever Friction Mechanism 6/2005

Applicability:

All EC 120 helicopters.

Requirement:

1.    Operation of the collective pitch lever friction mechanism by helicopter crews:

a.     Only slightly tighten the collective pitch lever friction.

b.    If stiff operation is felt in flight with the collective pitch lever, loosen the collective pitch lever friction immediately.

2.    Action in accordance with the instructions described in paragraph 2.B.2.a. of Eurocopter EC 120 Alert Service Bulletin (ASB) No. 67A009, or later EASA approved revision.

3.    Action in accordance with the instructions described in paragraph 2.B.2.b. of ASB No. 67A009, or later EASA approved revision.

Note:  DGAC AD F-2002-606 R1 refers.

Compliance:

1.    As from the next flight after 22 January 2003, and each flight thereafter; until compliance with Requirement 2.

2.    Within 110 flight hours or 3 months after 22 January 2003, whichever occurs first; and each time a replacement friction mechanism is installed on a helicopter.

3.    Within 110 flight hours or 13 months, whichever occurs first, following compliance with Requirement 2.

The compliance times remain unchanged by this issue.

This Amendment becomes effective on 9 June 2005.

Background:

A report was received of collective pitch lever stiffness during flight.  Investigation revealed an increased pad friction factor due to local unevenness of the pad material. 

Amendment 1 is issued in response to a revision of the related DGAC AD, which converts the Requirement document to an Alert Service Bulletin; with no change to the technical content.

David Villiers
Delegate of the Civil Aviation Safety Authority

27 April 2005