COMMONWEAL TH OF AUSTRALIA CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES (Civil Aviation Regulations 1998), PART 39 -105 Fokker F27 Series Aeroplanes AD/F27/96 Pitot Static System - Modification 9/78 Applicability: All model F27 aeroplanes with S/Nos. 10505 to 10547 and 10550. Document: 1. Fokker F27 SB No. 34-41; or 2. BLA 78-40-34. Compliance: Within 800 hours time in service after 30 September 1978.