COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Robin Aviation Series Aeroplanes AD/ROBIN/29 Hydraulic Lines 11/96 Applicability: All HR 100/250 and HR 100/285 series aircraft fitted with retractable landing gear. Requirement: Replace the inlet and outlet pipes of the Retractable Gear (R/G) hydraulic pump as required by Avions Pierre Robin SB No 148 dated April 26, 1996. Note: DGAC AD 96-147(A) refers. Compliance: Unless previously carried out, at the next scheduled aircraft maintenance inspection and thereafter, at every second disassembly of the pipes. Background: The manufacturer has advised that frequent removal and re-tightening of the tube fitting nuts located at the end of the fluid pipes has resulted in cracking of the tubing flares.