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. Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes AD/CONVAIR/10 Main Landing Gear Cylinders 5/2006 Applicability: Model 340 and 440 aircraft, and all such model aircraft converted to turbopropeller power. Requirement: 1. Inspect the entire outer surface of the main landing gear cylinders part numbers 528002 or 528402, including the fulcrum arms, for cracks using magnetic particle or dye penetrant methods, or approved equivalent method. If cracks are detected, before further flight, either rework the cylinder in a manner approved by the FAA, or replace the cylinder with a cylinder which has been inspected in accordance with Requirement 1, and is found to be free of cracks. 2. If cylinders are reworked, accomplish the following: a. Identify and record the cylinders and areas reworked. b. Limit the use of reworked cylinders to those aircraft operating below or at a maximum of 55,000 lbs. take-off gross weight. If any reworked cylinder is installed in any aircraft converted to turbopropeller power in accordance with STC SA4-1100 (known as Model 580), install a placard in only those aircraft previously approved for operating weights above 55,000 lbs., and in full view of the pilots, which reads as follows: "Maximum Take-off Gross Weight 55,000 lbs." 3. Repeat the Requirement 1 inspection. 4. If no cracks are detected during any Requirement 1 inspection, and it is determined that a cylinder has less than 14,000 hours time in service, repeat the Requirement 1 inspection. 5. If no cracks are detected during any Requirement 1 or 4 inspection, and a cylinder is determined to have more than 14,000 hours time in service, repeat the Requirement 1 inspection. Note: FAA AD 71-02-03 Amdt 39-1145 refers. Compliance: 1. Unless the initial inspection is already accomplished, within 50 hours time in service after 11 May 2006. 2. Before further flight. 3. At intervals not to exceed 1,000 hours time in service from the last inspection. 4. Before the accumulation of 15,000 hours time in service. 5. At intervals not to exceed 1,000 hours time in service from the last inspection. This Airworthiness Directive becomes effective on 11 May 2006. Background: The FAA requires inspections to detect cracking in the main landing gear cylinders. Undetected cracks could result in failure of a main landing gear. David Villiers Delegate of the Civil Aviation Safety Authority 29 March 2006