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 39.1 (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 rotorcraft 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/108 Tail Servo-Control 2/2005 TX Applicability: AS 350 B3 helicopters fitted with a GOODRICH tail servo-control part number (P/N) SC5071-XX or SC5072, except: - tail rotor servo-controls P/N SC5072 with a serial number equal to or above 1372, - tail rotor servo-controls overhauled or repaired in compliance with Service Bulletin GOODRICH No. SC507X-67-39-01-3, and - tail rotor servo-controls having never been removed since the delivery of a new rotorcraft. Requirement: 1. Intentional auto-rotation flight is prohibited until the check of the tail servo-control is accomplished in accordance with paragraph 2.B.2 of Alert Telex (AT) Eurocopter AS 350 No 67.00.30. or later DGAC approved revision. 2. Carry out the following in accordance with AT AS 350 No 67.00.30. or later DGAC approved revision: a. For helicopters not fitted with Automatic Flight Control System - comply with paragraph 2.B.2.a. b. For helicopters fitted with Automatic Flight Control System - comply with paragraph 2.B.2.b 3. Remove from service any servo-control that is found to be non-compliant as a result of the bench check carried out in accordance with paragraph 2.B.6. of the AT and install a compliant tail servo-control in accordance with paragraph 2.B.2 of the AT. 4. Check spare tail servo-controls in accordance with paragraph 2.B.6. of the AT. Note: DGAC AF UF-2004-196 (EASA approval 2004-12557) refers. Compliance: For Requirement 1 - As of the effective date of this Directive. For Requirement 2 - Within 50 hours time in service from the effective date of this Directive. For Requirement 3 - Before further flight after accomplishing Requirement 2. For Requirement 4 - Before installation on a rotorcraft. This Airworthiness Directive becomes effective on 7 January 2005. Background: The Direction Générale de l'Aviation Civile of France has advised that servos fitted with the incorrect servo piston could cause loss of tail rotor control authority during certain phases of autorotative flight. This Directive prohibits intentional autorotation flight until tail rotor servo-control systems are inspected and, if necessary, replaced. David Punshon Delegate of the Civil Aviation Safety Authority 6 January 2005