COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Short SD3-30 Series Aeroplanes AD/SD3-30/18 Fuselage Sealing 4/86 Applicability: All models with S/Nos SH3002 to SH3116. Requirement: Short SB SD330-53-58. Compliance: Prior to 31 July 1986. Background: Following an incident of a fuel purge valve failure, investigation indicated that, to safeguard against the possibility of fuel ingress into the main cabin, an improvement in fuselage top skin sealing is desirable.