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 125/139 Thrust Reverser - Control Circuit Wiring 4/94 Applicability: All BAe 125 Series 1000 aircraft identified in Raytheon Corporate Jets Incorporated Mandatory Service Bulletin SB.78-9-3662B dated 7 January 1994. Requirement: Incorporate Modification Number 253662B in accordance with Raytheon Corporate Jets Incorporated Mandatory Service Bulletin SB.78-9-3662B dated 7 January 1994. Note: This Service Bulletin has been classed as Mandatory by the CAA(UK). Compliance: Prior to 31 October 1994. Background: This Directive is issued to improve the integrity of the thrust reverser electrical control circuit and to correct the rudder bias not inhibited annunciation logic. This will prevent the application of high thrust reverse with an asymmetric configuration and uninhibited rudder bias before the condition is annunciated.