COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes AD/HS 748/15 Nose Landing Gear Jack Support Beam 5/95 Applicability: All HS748 aircraft pre modification 1472. Requirement: Retire from service Main Landing Gear Jack Support Beam P/N 48 D 11498. Note: CAA(UK) AD 004-02-89 and British Aerospace Mandatory Service Bulletin 53/55 refer. Compliance: Retire before: 1. 900 landings, if pre modification 684; or b. 3000 landings, if post modification 684. Note: Embodiment of Modification 1472 (SB 53/28) cancels the requirement of this AD. Background: Cracks have been reported in the subject nose landing gear jack support beam. Failure of this beam could result in an inability to extend or retract the nose landing gear. CAA(UK) compliance was 31 May 1989, this AD is issued to ensure aircraft recently imported into Australia meet this requirement.