COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES British Aerospace BAe 125 Series Aeroplanes AD/HS 125/135 Fire Protection Circuitry - Inspection of Blocking Diodes 4/93 Applicability: All series 125 aircraft identified in Corporate Jets Limited Service Bulletin S.B. 26-33 dated 8 December 1992. Requirement: Action in accordance with the Accomplishment Instructions of Corporate Jets Limited Service Bulletin S.B. 26-33 dated 8 December 1992. Note: This Service Bulletin has been classified as Mandatory by the CAA(UK), AD 012-12-92 refers. Compliance: Prior to 1 May 1993. Background: This Directive has been issued following reports of isolated cases of dormant failure of the blocking diodes associated with the 'EXT FIRED' (bottle gone) indicators. Compliance with this Directive will provide improved system integrity.