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. Dassault Aviation Falcon 2000 Series Aeroplanes AD/F2000/21 Wing Anti-Ice Telescopic Tubes 12/2006 Applicability: Falcon 2000 aircraft fitted with wing anti-ice telescopic tubes having Part Number (P/N) 5035-400 or 5035-500. Requirement: 1. Remove and modify the affected tubes in accordance with instructions contained in Zodiac SB 5035-30-001 and 5035-30-002. 2. Do not install an affected telescopic tube P/N 5035-400 or 5035-500 in any aircraft as replacement part, unless it has been modified in accordance with instructions contained in Zodiac SB 5035-30-001 and 5035-30-002. Note: EASA AD 2006-0276 dated 6 September 2006 refers. Compliance: 1. Before the telescopic tubes P/N 5035-400 and 5035-500 exceed the limit of 2,400 Flight Hours (FH) or 2,000 Flight Cycles (FC) time-in-service (TIS) since new, whichever occurs first; and For telescopic tubes P/N 5035-400 and 5035-500 that have already exceeded or will exceed 2,400 FH or 2,000 FC TIS within the next 330 FH or 7 months after the effective date of this AD, within 330 FH or 7 months, whichever occurs first after the effective date of this AD. 2. From 16 April 2007. This Airworthiness Directive becomes effective on 23 November 2006. Background: The wing anti ice telescopic tubes (P/N 5035-400 and 5035-500) ball joints were originally designed with high temperature polymer (Kynel™) sealing rings. Temperature induced cracking of these rings associated with long term wear has been encountered in a small number of cases. This degradation may lead to binding of the ball joint and high swivelling forces which may result in improper operation of the leading edge slats and also in failure of the ball joint mounting bracket with possible friction on the aileron control rod, which could lead, if combined with a failure of the aileron emergency actuator, to an aileron jamming. The purpose of this AD by requiring modification of the wing anti-ice telescopic tubes in accordance with the ZODIAC service bulletins is to ensure that no old type sealing rings remain in operation beyond a life limit of 2,400 flight hours or 2,000 flight cycles. James Coyne Delegate of the Civil Aviation Safety Authority 12 October 2006