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 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. AMD Falcon 50 and 900 Series Aeroplanes AD/AMD 50/31 Hydraulic Line Chafing 7/2003 TX Applicability: Dassault Aviation Mystere Falcon 50 aeroplanes with serial numbers 2 though 329 inclusive. Requirement: 1. Carry out an inspection and measurement of the hydraulic lines in accordance with Dassault Aviation Service Bulletin (S/B) F50-A370. 2. Replace any chafed hydraulic lines as detailed in the replacement criteria of Dassault Aviation S/B F50-A370. 3. Ensure that the hydraulic lines as detailed in Dassault Aviation Service Bulletin S/B F50-A370 are fitted in accordance with Dassault Aviation Service Bulletin S/B F50-A370. 4. Incorporate temporary revision F50-WC-844.0/1 into the Airframe Maintenance Manual. Note: DGAC Telex AD T2003-190(B) refers. Compliance: 1. Within 3 flights from the effective date of this Directive. 2. Within the time limits as detailed in the replacement criteria of Dassault Aviation S/B F50-A370. 3. Within 3 flights from the effective date of this Directive. 4. Within 3 flights from the effective date of this Directive. This Airworthiness Directive becomes effective on 14 May 2003. AMD Falcon 50 and 900 Series Aeroplanes AD/AMD 50/31 (continued) Background: During lubrication of the teleflex engine controls located within the engine pylon, clamps locating the hydraulic lines can be undone to gain access to the teleflex cables. Failure to reinstall the clamps properly can lead to failure of the hydraulic lines, due to chafing, and subsequent failure of the hydraulic system. David Villiers Delegate of the Civil Aviation Safety Authority 9 May 2003 The above AD is notified in the Commonwealth of Australia Gazette on 14 May 2003.