AD/AS 355/84 Amdt 2 Stabilisers Upper and Lower Vertical Fin Spars (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/AS 355/84 Amdt 1 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 AS 355 (Twin Ecureuil) Series Helicopters

AD/AS 355/84 Amdt 2 Stabilisers - Upper and Lower
Vertical Fin Spars 9/2008

Applicability:

Model AS 355 helicopter versions E, F, F1, F2, and N, without Eurocopter Alert Service Bulletin No. 55.00.11 incorporated.

Requirement:

Inspect the spar of the upper and lower fins for cracks in accordance with Eurocopter AS 355 Alert Service Bulletin No. 05.00.44, or later EASA approved revision.

If a crack is found in one of the spars, before further flight, replace the affected vertical fin in accordance with Maintenance Manual Work Card 55.00.00.402.

Note 1:  EASA AD 2006-0096 refers.

Note 2:  Accomplishment of AD/AS 355/98 constitutes terminating action to the requirements of this Directive.

Compliance:

Within 25 flight hours after 12 January 2005, and thereafter at intervals not to exceed 110 flight hours.

The compliance time remains unchanged by this issue of the Directive.

This Amendment becomes effective on 28 August 2008.

Background:

Reports were received of cracks discovered in the spar of the upper vertical fin on two AS 355 N helicopters.  Undetected cracking on the attachment spar of a vertical fin could lead to failure of the spar, and result in loss of the vertical fin.

Amendment 1 converted the Requirement document to an Alert Service Bulletin with the same reference number and limited aircraft applicability.  There is no change to the technical content of the directive.

Amendment 2 is issued to introduce AD/AS 355/98, which provides mandatory terminating action to the requirements of this Directive.

David Villiers
Delegate of the Civil Aviation Safety Authority

17 July 2008