COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Hot Air Balloons AD/BAL/6 Blanking Hose Ends 5/86 DM Applicability: All balloons. Requirement: Any hose disconnected from a system shall have a pressure seal blank fitting installed on the unattached end. Compliance: Any time one end of a hose is disconnected and the other end remains connected to a source of pressurized LPG. Background: Some operations are conducted with one or more cylinders of a manifold system removed. In these cases operators rely on the seals of the hose end fitting disconnect check valve to retain pressurized LPG.