COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-42 (Cheyenne III) Series Aeroplanes AD/PA-42/23 Aileron Hinge 11/97 Applicability: Model PA-42, PA-42-720, PA-42-720R, and PA-42-1000 aircraft with serial numbers as listed in Piper Service Bulletin (SB) 967. Requirement: 1. Inspect (using dye penetrant methods) the area beneath and in the area of the inboard aileron hinge bracket on the aileron spar for cracks in accordance with the Instructions section of Piper SB 967. If cracks are found on the aileron spar: (a) Inspect the corresponding aileron rib at the inboard aileron hinge bracket location; and (b) Replace any cracked spar assembly and any cracked aileron rib in accordance with the maintenance manual; 2. Replace the inboard aileron hinge brackets with a part of improved design P/N 74461-02 (left) and P/N 74461-03 (right), in accordance with the Instructions section of Piper SB 967, unless already accomplished. Note: FAA AD 96-21-03 Amdt 39-9780 refers. Compliance: For Requirement 1 and 2 : Upon the accumulation of 3,000 hours total time in service, or within 200 hours time in service after 9 October 1997, whichever occurs later, unless already accomplished. This airworthiness directive becomes effective on 9 October 1997. Background: The FAA received several reports of cracks in the vicinity of the inboard aileron hinge bracket, aileron spar, and aileron rib. The actions required by this Directive are intended to prevent structural failure of the aileron, which could result in loss of control of the aircraft.