COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Gates Learjet 35 and 36 Series Aeroplanes 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. AD/LEARJET 35/38 Main Landing Gear Tyre 7/2001 DM Applicability: All Model 35, 35A, 36, and 36A aircraft, fitted with Goodyear main landing gear tyre(s) part number 178K23-5 within the serial number range of 0148xxxx through 0152xxxx. Requirement: Perform a general visual inspection of the main landing gear tyres to determine if any tyre has Goodyear part number 178K23-5 within the serial number range of 0148xxxx through 0152xxxx, in accordance with Bombardier (Learjet) Advisory Wire 32-021, dated 5 February 2001. Replace, before further flight, any tyre that has Goodyear part number 178K23-5 and is within the serial number range specified in the inspection criteria. Note 1: FAA AD 2001-07-11 Amdt 39-12177 refers. Note 2: Goodyear Service Bulletin GY SB 2001-32-001 refers. Note 3: If any tyre has part number 178K23-5 but its serial number is not in the range 0148xxxx through 0152xxxx, no further action is required by this Directive. Compliance: Before 28 May 2001, unless already accomplished. This Airworthiness Directive becomes effective on 23 May 2001. Background: The main landing gear tyre manufacturer reported that certain Goodyear Flight Eagle tyres have experienced tread separation. Approximately 300 tyres have been identified as possibly defective. David Alan Villiers Delegate of the Civil Aviation Safety Authority 16 May 2001 The above AD is notified in the Commonwealth of Australia Gazette on 23 May 2001.