COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-31 Series Aeroplanes AD/PA-31/114 Amdt 3 Main Landing Gear Forward Side Brace 9/96 Applicability: PA-31 aircraft with models and serial numbers listed in Part I of Piper SB No 845A, except those aircraft fitted with improved landing gear forward side braces in accordance with Part II of Piper SB No 845A. Requirement: 1. Remove the main landing gear (MLG) forward side braces and inspect in accordance with Part I of Piper SB No 845A, except that the paint is to be removed from the entire component and the entire component is to be inspected in accordance with an approved fluorescent dye penetrant procedure. 2. Replace both the left and right MLG side braces with parts of improved design, P/N 85165-02 (left) and P/N 85165-03 (right) or P/N 85166-02 (left) and 85166-03 (right), as applicable. Note 1: CAO 108.10 Appendix II constitutes an approved procedure for the purpose of this AD inspection. Note 2: Colour contrast (red dye) penetrant systems are not considered sufficiently sensitive to detect the type of cracking expected. Note 3: FAA AD 96-10-14 Amdt 39-9621 refers. Compliance: 1. Inspect the main landing gear forward side braces before 1000 hours component time in service, or before the issue of the next Maintenance Release after 4 March 1993, whichever occurs last. Repeat the inspection before the issue of each Maintenance Release and following any occasion on which the landing gear is operated at speeds above the maximum landing gear operating speed specified in the applicable aircraft Flight Manual; until Requirement 2 of this AD is accomplished. 2. Unless already accomplished, within 1,200 hours time in service after 15 August 1996. The compliance of the previous issue of this Directive remains unchanged. This Amendment is effective from 15 August 1996. Background: Cracking has been experienced in the MLG forward side braces, failure of which could cause landing gear collapse. Amendment 2 required the removal of the side braces from the aircraft and a more sensitive inspection of the entire component. It followed the discovery, in several Australian aircraft, of fine fatigue cracking which could not be reliably detected with colour contrast penetrant systems. Cracking was also discovered in areas not covered by the Piper SB. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Amendment 3 is issued in response to a new Country of Origin AD, which requires incorporating both a left and right MLG forward side brace of improved design as terminating action for the repetitive inspection requirement. The Federal Aviation Administration's policy on ageing commuter class aircraft is to eliminate or, in certain instances, reduce the number of repetitive short interval inspections when improved parts or modifications are available. The original issue of this Airworthiness Directive became effective on 31 October 1986. Amendment 1 of this Airworthiness Directive became effective on 24 March 1988. Amendment 2 of this Airworthiness Directive became effective on 4 March 1993.