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 125/59 Cold Air Unit Fragmentation Guard - Installation 3/82 Applicability: As detailed in the requirement document. Document: British Aerospace HS 125 SB No. 21-123-(2815). Compliance: Before 31 March 1983. Background: A fragmentation guard is installed around the fan housing of the cold air unit to protect the main engine beam in the event of a fan bursting failure.