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 748/7 Flight Control System Bearing Retaining Rings 13/94 Applicability: All HS748 aircraft. Requirement: Action in accordance with British Aerospace Mandatory Service Bulletin 27/110. Note: UK CAA AD 006-03-87 refers. Compliance: At the inspection intervals specified in paragraph 2.A and 2.B of the Requirement Document Accomplishment Instructions. Background: The UK CAA requires an on-going check for the security of bearings in housings held in place by Walker Schofield retaining rings.