What is the primary purpose of fire and overheat detection systems on an aircraft?

• A. To automatically extinguish fires
• B. To forewarn you and the crew of any abnormalities or impending fire or overheat
• C. To measure fuel levels
• D. To control cabin pressure

Answer: (B)

The main purpose of fire and overheat detection systems is to provide an early warning to the crew of any abnormalities or signs that a fire or excessive heat may be developing. Sensors placed in critical areas monitor temperatures and other indicators, and when values exceed safe limits, a warning is issued in the cockpit through lights and alarms. This alerts pilots and crew so they can quickly diagnose the situation, isolate the affected area, shut down or reconfigure systems as needed, and deploy fire suppression if required. While fire suppression and system control are part of the overall response, the detection system itself is about warning and awareness, not automatically putting the fire out. The other options describe functions handled by different systems (fuel level measurement, cabin pressure control), which are not the primary roles of fire and overheat detectors.