AD/AS 355/73 Amdt 1 - Flight Control Stop Screws (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 355/73 and issues the following AD under subregulation 39.1 (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 355/73 Amdt 1

Flight Control Stop Screws 9/2004

Applicability: Models AS 355 E, F, F1, F2, and N helicopters; without MOD 073206 or MOD 073102 incorporated.

Components affected: roll, pitch, and collective flight control stops.

Requirement: 1. Action in accordance with paragraph 2.B.1. of Eurocopter Alert Service Bulletin AS 355 No. 67.00.25 R1.

2. Action in accordance with paragraph 2.B.2. of Eurocopter Alert Service Bulletin AS 355 No. 67.00.25 R1.

Note: DGAC AD F-2003-322 R1 refers.

Compliance: 1. Within 100 flight hours after 30 October 2003, unless already accomplished.

2. Within 500 flight hours or 1 year after 30 October 2003, whichever occurs first. The compliance time remains unchanged by this issue. This Amendment becomes effective on 2 September 2004.

Background: A report was received of an incident during a ground run-up with a Model EC 120 helicopter, where it was possible to push the collective lever downward beyond it's normal position. Investigation revealed that the locknut of the low pitch stop had come loose and that the stop was out of adjustment. The worst case scenario is that of collective low pitch stop maladjustment, which can result in rotor under-speed in an auto-rotation situation.