COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES British Aerospace BAe 146 Series Aeroplanes AD/BAe 146/27 Amdt 1 Passenger and Service Door Mechanism 9/91 Applicability: Models & Constructors numbers; as specified in BAe 146 SB 52-89-00668H, J, K & L Revision 2. Requirement: Action in accordance with BAe Mandatory SB 52-89-00668H, J, K & L Revision 2. Compliance: Prior to 31 October 1991. Background: Constant high outward force on the door during opening sequence may prevent the side baulk blade from retracting, this hindering emergency evacuation. Modifications required by the initial issue of this Directive introduced stronger springs to increase tension at the side baulk blade. This amendment requires additional work for aircraft already modified, due to a dimension error. Compliance date required by the UK CAA is extended by three months.