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/48 Wing Main Spar Access Panel - Cold Worked Holes Applicability: All series 3200 aircraft up to and including constructor number 922. 10/91 Requirement: Action in accordance with the Requirements of BAe Service Bulletin 57-JM 8160, dated 19 June 1991. Note: This Service Bulletin is classified as Mandatory by the UK CAA. Compliance: Prior to exceeding 6000 flights, or prior to 31 December 1991, whichever is the later. The Australian CAA recommend early compliance. Background: Multi-site cracking of the wing main spar webs has been found on the Jetstream Series 3200 wing fatigue test specimen. Cold expansion of the critical holes is to designed to improve the structures resistance to cracking.