General Authority of Civil Aviation (GACA) Aeronautical Information Publication (AIP) Practice Exam

What occurs if the AFT CARGO FIRE "ARM" switch is pushed after extinguishing a forward cargo fire?

1. The aft compartment discharges immediately

2. The arming functions activate but no discharge occurs

3. Both forward and aft compartments are discharged

4. Only the aft compartment valve is armed

The correct answer is: The arming functions activate but no discharge occurs

When the AFT CARGO FIRE "ARM" switch is pushed after extinguishing a forward cargo fire, the function of the arming switch is critical to the operation of the fire suppression system. The correct answer indicates that when the switch is activated, the arming functions become active, but no discharge occurs at that moment. In general aviation safety protocols, arming a system indicates that the capabilities for deploying a fire extinguishing agent are ready to be utilized. However, if a fire has just been extinguished in another compartment, the system typically won't automatically discharge again since the crew would need to assess and ensure that a fire persists before deploying any extinguishing agents. This design is crucial for preventing unnecessary discharges, which could lead to wasted extinguishing agent or harm the aircraft's systems unnecessarily. Understanding how these systems work is essential for flight safety and maintenance procedures. Proper knowledge of the cargo fire suppression system helps ensure that actions taken in the cockpit are appropriate based on the current status of the aircraft's systems.