COMMONWEALTH OF AUSTRALIA CIVIL AVIATION ORDERS CIVIL AVIATION SAFETY AUTHORITY PART 105 SCHEDULE OF AIRWORTHINESS DIRECTIVES GULFSTREAM (GRUMMAN) G.159 SERIES AEROPLANES AD/G159/42 Electrical Power Distribution Protection 1/89 Applicability: All models. Requirement: Action in accordance with Gulfstream Mandatory Aircraft Service Change No 262. Compliance: Prior to 26 January 1990. Background: In all serial numbers of the G1, the APU generator output sensing wires are routed from the APU to the generator over-voltage protector without any circuit protection. Additionally, in some aircraft, the APU generator feeders themselves do not have circuit protection, and the inverter circuit protection currently provided is insufficient to protect the aircraft. This AD provides fault protection.