COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Aerospatiale GY 80 (Horizon) Series Aeroplanes AD/GY80/7 Propeller Governor Oil Inlet Union - Replacement 6/79 Applicability: All GY80 aircraft fitted with variable pitch Hartzell propeller. Document: Aerospatiale Horizon SB No. 37. Compliance: Within 100 hours time in service after 31 July 1979. Background: This Directive is issued as the result of overseas notification of oil loss caused by failure of the crankcase mounted union.