COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES 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 CAR 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. Learjet 45 Series Aeroplanes AD/LJ45/5 Horizontal Stabiliser Actuator Assembly 5/2003 TX Applicability: Learjet Model 45 aeroplanes with serial numbers 45-001 through 45-232 inclusive. Requirement: 1. Carry out an inspection to determine the part number (P/N) of the horizontal stabiliser actuator assembly (A66) in accordance with Paragraph 2 of the Accomplishment Instruction of Bombardier Learjet Alert Service Bulletin (ASB) A45-27-15 dated 20 March 2003. 2. If, as a result of the Requirement 1 inspection, an horizontal stabiliser actuator assembly (A66) with either P/N 6627401000-001 or 2A9200F is found to be installed, replace the actuator assembly with a new actuator assembly P/N 6627401000-005 in accordance with Paragraph 2 of the Accomplishment Instruction of ASB A45-27-15. 3. Horizontal stabiliser actuator assembly (A66) with either P/N 6627401000-001 or 2A9200F may not be installed on any aeroplane as a replacement part. Note: FAA Emergency AD 2003-06-51 refers. Compliance: For Requirements 1 and 2 - Before further flight after the effective date of this Directive. For Requirement 3 - As of the effective date of this Directive. This Airworthiness Directive becomes effective on 21 March 2003. Background: Learjet has received a report of an horizontal stabiliser actuator assembly (A66) internal structural failure which has resulted in excessive linear free play. This free play could result in possible loss of control of the aeroplane. This Directive requires an inspection to determine the part number of the installed actuator assembly and, if necessary, replacement of the actuator. James Coyne Delegate of the Civil Aviation Safety Authority 21 March 2003 The above AD is notified in the Commonwealth of Australia Gazette on 21 March 2003. Page 1 of 1