COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 747 Series Aeroplanes AD/B747/97 Cargo Fire Extinguishing Agent Containers 9/91 Applicability: Model 747-400 series as listed in Boeing SB 747-26A 2180. Requirement: Action in accordance with the Technical Requirements of FAA AD 91-12-03 Amdt 39-7014. Compliance: As specified in the Requirement Document with a revised effective date of 5 September 1991 for Australian registered aircraft. Background: The FAA has received a report from one operator identifying two occurrences of false indication of low pressure in the cargo compartment fire extinguishing containers. This condition, if not corrected, could reduce or stop the discharge of fire extinguishing agent due to water freezing in the metered distribution lines, and could cause false low pressure indications in the initial discharge indicating system.