COMMONWEALTH OF AUSTRALIA CIVIL AVIATION ORDERS CIVIL AVIATION SAFETY AUTHORITY PART 105 SCHEDULE OF AIRWORTHINESS DIRECTIVES GULFSTREAM (GRUMMAN) G.159 SERIES AEROPLANES AD/G159/19 Amdt 4 Landing Gear 13/89 Applicability: All models. Requirement: Carry out a fluorescent dye NDI for cracking of the landing gear aluminium forgings in accordance with Gulfstream Customer Bulletin No. 228B. Compliance: Within 150 landings after 28 December 1989, or since last overhaul whichever is the later, thereafter in accordance with the G1 Inspection Schedule. Background: The manufacturer has specified a range of NDI procedures to relieve this inspection, and enable inclusion into the Inspection Schedule. The Authority has called up fluorescent dye as the most suitable for Australia conditions.