COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 747 Series Aeroplanes AD/B747/27 Escape Slide Flapper Valve - Modification 2/81 Applicability: All models 747 with B.F. Goodrich escape slides and turbo fans identified in B.F. Goodrich SB No. 25-060 dated 14 July 1980. Documents: 1. FAA AD 80-20-02, Amendment 39-3928; or 2. Boeing SB 747-25-2543; OR 3. B.F. Goodrich SB 25-060. Compliance: Before 1 January 1981. Background: Some escape slides on overseas aeroplanes have failed to inflate correctly during emergency test inflation.