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-23/79 Stabilator Assembly Lower Surface - Inspection 10/79 Applicability: All model PA-23-250 (six place) with S/Nos. 27-7654001 to 27-7954044, fitted with stabilator S/Nos. referenced in Piper SB No. 606. Document: Piper SB No. 606. Compliance: Within 100 hours time in service after 31 October 1979 and there- after at intervals not exceeding 100 hours time in service until stabilator assembly is replaced or modified in accordance with SB No. 606. Background: The manufacturer has determined that the affected stabilator assemblies may not have proper bonding between the ribs and skins.