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 748/22 Main Hydraulic Accumulators - Corrosion Inspection Applicability: British Aerospace HS748 aircraft. 7/97 Requirement: Inspect the main hydraulic accumulators for corrosion and repair as required, in accordance with British Aerospace Service Bulletin HS748-29-49 issued Feb 25/97. Compliance: Within 30 days from effective date of this Directive and thereafter every two years. This Airworthiness Directive becomes effective on 19 June 1997. Background: Extensive corrosion has been found under the mounting brackets of the main hydraulic accumulators of an operator's aircraft during unscheduled maintenance which required removal of the accumulators.