Ad/Ecureuil/114 - Tail Rotor Drive Shaft (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/114 Tail Rotor Drive Shaft 12/2005 TX

Applicability:

AS 350 B3 and EC 130 B4 helicopters.

Requirement:

1.    Incorporate the revisions referenced below in the maintenance documentation, according to the helicopter model.

2.    Comply with the maintenance operations specified in the referenced revisions, according to aircraft version.

AS 350 B3:

-      Temporary revision 005a of the PRE, section 05.99.

-      Revision of the Work Card No. 65.10.00.601, paragraph 2.2.3 introduced by rush revision No 23 b of the MET or further approved revisions.

EC 130 B4:

-      Temporary revision 007a of the MSM, chapter 04.

-      Revision of the Task No. 65-11-00, 6-2 introduced by temporary revision No. 5b of the AMM or further approved revisions.

Note:  DGAC AD F-2005-158 EASA approval No. 2005-6222 dated 6 September 2005 refers.

Compliance:

1.    Unless previously accomplished, within 3 days from the effective date of this Directive.

2.    Repetitively at intervals of 110 flight hours after the effective date of this Directive.

This Airworthiness Directive becomes effective on 30 September 2005.

Background:

This Directive is issued following the discovery of wear on the tail rotor drive shaft at bearing No. 4 under the elastomer sleeve.  The presumed cause is rotation of the sleeve on the shaft.

Wear of the drive shaft could lead to failure of the shaft and loss of the tail rotor drive.

A check of the elastomer sleeves, and in particular, to ensure that there is no rotation of the sleeves on the shaft has been introduced in the airworthiness limitations section by the revisions referenced above.

James Coyne
Delegate of the Civil Aviation Safety Authority

28 September 2005