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/GY80/1 Fuel System - Inspection and Modification 10/69 Applicability: All models with S/Nos. prior to No. 125. Requirement: 1. Inspect the fuel supply lines from each wing tank where they pass through the wing-root/fuselage structure for any evidence of chafing. If chafing has occurred replace the affected pipes. 2. In the region where the fuel supply lines pass through the wing-root and fuselage structure, protect the pipes against possible chafing by means of a suitable piece of split rubber hose secured around the pipe in the critical area; or 3. Sud Aviation SB No. 28. Compliance: 25 November 1969.