COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES GAF N22 and N24 Series Aeroplanes AD/GAF-N22/56 Amdt 1 Rudder Pedal Pivot Arms 10/95 Applicability: All N22 and N24 aircraft (including pre Mod N33 configuration). Requirement: 1. For pre Mod N794 Rudder Pedal Pivot Arms:- (a) Remove the rudder pedal pivot arms from the aircraft and perform a fluorescent dye penetrant inspection around the shaft housing in accordance with ASTA Service Bulletin ANMD-27-42, Revision 3, Accomplishment Instructions A.Part 1.(1). (b) Treat the inside of the rudder pedal pivot arms for corrosion in accordance with ASTA Service Bulletin ANMD-27-42, Revision 3, Accomplishment Instructions B.Part 2.(6),(12)&(13). It is recommended that Mod N794 be incorporated in its entirety at this time. If Mod N794 is incorporated at a later time, it will be necessary to repeat the corrosion protection treatment after welding. Pedal pivot arms exhibiting severe corrosion, in the form of loose rust flakes or severe pitting, are to be scrapped. 2. For post Mod N794 Rudder Pedal Pivot Arms:- (a) Visually inspect the rudder pedal pivot arms using 10x magnification, in accordance with ASTA Service Bulletin ANMD-27-42, Revision 3, Accomplishment Instructions A.Part 1.(2). Compliance: 1. (a) Action in accordance with Requirement paragraph 1(a) before 1000 hours component time in service, or before 14 October 1995, whichever occurs last. Repeat the inspection at intervals not to exceed 300 hours component time in service. 1. (b) Unless previously done, action in accordance with Requirement paragraph 1(b) not later than the next fluorescent dye penetrant inspection after 30 September 1995. 2. Action in accordance with Requirement paragraph 2 at intervals not exceeding 1800 hours component time in service or before 14 October 1995, whichever occurs last. Background: Major defect reports have been received of cracking in both pilot and co-pilot rudder pedal pivot arms at times in service as low as 1400 hours. If not detected, cracks could progress to a point where aircraft control may be impeded. The omission of internal corrosion treatment at manufacture, and subsequent internal corrosion, exacerbates the problem. This Amendment reduces the inspection threshold and introduces a corrosion treatment for unmodified arms, and introduces a visual inspection for modified arms. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES