AD/As 355/85 Amdt 2 Sliding Door Rear Fitting Pin (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 355/85 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 355/85 Amdt 2 Sliding Door Rear Fitting Pin 11/2006

Applicability:

Model AS 355 helicopters, versions E, F, F1, F2, and N; equipped with sliding door(s); and without MOD 073298 and/or 073308, or ASB No. 52.00.23 incorporated.

Requirement:

1.    Check the support shaft of the rear roller and the rear fitting of the sliding door(s) for cracks, in accordance with paragraph 2.B. of Eurocopter Alert Service Bulletin (ASB) No. 05.00.45.

2.    Replace the roller support shaft and fitting of the left hand and/or right hand sliding doors in accordance with paragraph 2.B. of ASB No. 05.00.23.

3.    Before installation on a helicopter of sliding door(s) held as spares, and referenced in paragraph 1.A.2. of ASB No. 52.00.23, accomplish paragraph 2.B. of ASB No. 52.00.23.

4.    Scrap the stock of shafts part number 350A 25-1275-20 and roller support fittings part number 350A 25-1270-20, in accordance with paragraph 2.B.5 of ASB
No. 52.00.23.

Note:  EASA AD 2006-0251 R1 refers.

Compliance:

1.a.           For aircraft equipped with sliding doors that have logged less than 90 flight hours:

                 Upon accumulating 110 flight hours.  Inspect thereafter at intervals not to exceed 110 flight hours, until accomplishment of Requirement 2.

1.b.           For aircraft equipped with sliding doors that have logged 90 or more flight hours:

                 Unless the initial inspection is already accomplished, within 20 flight hours after 26 October 2006.  Inspect thereafter at intervals not to exceed 110 flight hours, until accomplishment of Requirement 2.

2.              Before 1 July 2007.

3. and 4.   Before 1 July 2007.

This Amendment becomes effective on 26 October 2006.

Background:

The manufacturer received a report of failure and a report of cracking of the sliding door rear roller support pin.  Investigation revealed that the cracks started from a spring pin bore and grew due to fatigue.  Metallurgical analysis revealed heat treatment non-conformity of the pin material.

Amendment 1 was prompted by reports of cracking and failure of the roller support shaft rear attaching fitting.

Amendment 2 is issued in response to a new EASA AD, which converts the Requirement document to an Alert Service Bulletin with the same reference number, and mandates modification action that cancels the inspection requirements of this Directive.

David Villiers
Delegate of the Civil Aviation Safety Authority

13 September 2006