COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters AD/BELL 206/24 Engine Chip Detector Indicator - Installation 6/70 Applicability: All model 206A prior to S/No. 441 and model AB-206A. Document: Bell SL No. 206A-129. Compliance: Within 100 hours time in service after 30 June 1970. Background: AD/Agusta 206/16 equivalent.