COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES British Aerospace BAe 3100 (Jetstream) Series Aeroplanes AD/JETSTREAM/80 Elevator Bias Spring Assembly Bearing 13/98 Applicability: All Jetstream Series 3100 and Series 3200 aircraft. Requirement: Action in accordance with BAe Regional Aircraft Mandatory Service Bulletin (SB) 27-A-JA980606 Revision 1. Note: On aircraft with SB 27-A-JA980606 (original issue) incorporated, no further action is required. Compliance: Unless already accomplished, before 31 January 1999. This Airworthiness Directive becomes effective on 3 December 1998. Background: The manufacturer received a report from an operator of the detachment of the link that connects the bias spring to the elevator quadrant in the elevator control system. The failed bearing is designed to accommodate only a limited amount of misalignment and the failure has been attributed to a twist force applied by the spring due to the incorrect orientation of the spring hook ends.