COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Chrislea CH-3 Series Aeroplanes AD/CH-3/3 Front Seat Restraint Installation - Modification 9/72 Applicability: All models. Requirement: Modify each front seat restraint installation by fitting a safety harness in accordance with a scheme approved by the Secretary. Note: Guidelines for installation schemes are outlined in Airworthiness Advisory Circular No. 62 dated March 1972. Compliance: Before 1 October 1973.