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 206/82 Centre Post Installation - Structural Attachment - Inspection and Modification 2/80 Applicability: All model 206L with S/Nos. 45004 to 45153 and 46601 to 46617. All model 206L-1 with S/Nos. 45154 to 45299. Document: Bell Technical Bulletin No. 206L-79-41. Compliance: As per the requirement document. Background: The manufacturer has advised that cracks have been found during periodic inspections of the centre post structural attachment area.