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/43 Flying Controls - Audible Warning 6/91 T Applicability: All Jetstream series 3100 aircraft. Requirement: Action in accordance with the British Aerospace Alert Service Bulletin 27-A-JA 910340. Note 1: This Alert SB is classified MANDATORY by the CAA (UK). Note 2: CAA (UK) Airworthiness Directive 017-03-91 also refers. Compliance: Prior to 15 April 1991. Background: Action in accordance with the requirement document is necessary in order to avoid the possibility of uncommanded nose-down pitching motion of the aircraft when conducting landings with the wing flaps extended to 50 degrees and with ice present on the tailplane.