AD/Ecureuil/115 Tail Rotor Drive Shaft Rivets (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/115 Tail Rotor Drive Shaft Rivets 1/2006

Applicability:

Eurocopter EC 130 B4 helicopters delivered before 1 January 2005.

Requirement:

1.    Check that there are no cracks and no loose rivets in the tube-to-flange attachment of the tail rotor drive centre section shaft, and check the perpendicularity of bearing No. 1, in accordance with paragraph 2.B. of Eurocopter EC 130 Alert Service Bulletin (ASB) No. 65A002 dated
16 November 2005 or later DGAC approved revisions.

2.    -   If a crack or a loosened rivet is found, replace the tail rotor drive centre section shaft.

       -   If the out-of-perpendicularity of the bearing is more than 0.1 mm, carry out the procedure described in paragraph 2.B.2. of ASB No. 65A002 or later DGAC approved revisions.

Note:  DGAC AD F-2005-190 EASA approval No. 2005-6410 dated 15 November 2005 refers.

Compliance:

1.    Within 50 flying hours or three months after the effective date of this AD, whichever occurs first.

2.    Before the next flight after the effective date of this AD.

This Airworthiness Directive becomes effective on 19 January 2006.

Background:

There have been several cases of loosened rivets in the tube-to-flange attachment of the tail rotor drive centre section shaft.  In one case, this loosening of rivets was associated with a crack in the tube which started from a loosened rivet hole.  These occurrences can lead to failure of the tail rotor drive centre section shaft.

James Coyne
Delegate of the Civil Aviation Safety Authority

30 November 2005