COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Hot Air Balloons AD/BAL/14 Fast Flow Restrictor Valves 11/95 DM Applicability: All hot air balloons. Requirement: Inspect LP gas cylinders for fitment of fast flow restrictor valves and remove if fitted. Note: Inspection of LP cylinders for fitment of restrictor valves may be accomplished by an AS2337- approved gas cylinder test station or by an operational check of each cylinder, with burner alight. Compliance: Before further flight. Thereafter, following any maintenance, or inspection for date stamping. Background: There have been cases reported of fast flow restrictor valves being fitted internally to LP gas cylinders during maintenance. Because a balloon burner uses fuel within the operating range of the fast flow restrictor valve, a serious accident could result.