COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-23 (Apache and Aztec) Series Aeroplanes AD/PA-23/30 Rudder Trim Tab Horn - Inspection 5/63 Applicability: Models PA-23 and PA-23-160. Requirement: 1. Visually inspect, with at least a 10X magnifying glass, the rudder trim tab horn attach rivets for looseness or evidence of rivet working and the adjacent tab skin for cracks. If skin cracks, loose or working rivets are found, visually inspect the rudder trim tab support rib P/N 17468-17 for cracking; or 2. FAA AD 63-7-3. Compliance: Not later than 700 hours total time in service and thereafter at intervals not exceeding 100 hours time in service.