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 125/93 Electrical Power - DC Bus Tie System 8/88 Applicability: All BAe 125 aircraft post mod 251335. Requirement: Action in accordance with BAe 125 SB 24-264. Compliance: Prior to 6 October 1988. Background: BAe have advised that a case has occurred where the PS1 and PS2 DC bus bars remained electrically connected with the bus-tie contactor opened.