COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-34 (Seneca) Series Aeroplanes AD/PA-34/9 Rudder Servo Trim Tab - Inspection 6/73 Applicability: All models not incorporating modification kit P/N 760 800 V. Document: Piper SB No. 390A. Compliance: Within 10 hours time in service after 25 June 1973 and thereafter at intervals not exceeding 100 hours time in service.