During testing the fire detection system, which CAS messages should be observed?

• A. Red ENGINE FIRE and Amber FIRE DETECT CAS message
• B. Red ENGINE FIRE only
• C. Amber FIRE DETECT CAS only
• D. No messages

Answer: (A)

During a fire-detection test, you’re checking both the warning and the detection status, to confirm the system annunciates properly. The red ENGINE FIRE warning is the primary cue that a fire is detected in the engine, demanding immediate action. At the same time, the amber FIRE DETECT CAS message confirms that the fire-detection circuit has sensed a fire condition and is communicating that status to the crew. Seeing both together shows that the detection system is functioning and that the warning logic will drive the appropriate crew responses. If only one appears, you’re not fully validating the annunciation sequence; if none appear, the test would indicate a fault or incomplete test. Therefore, the correct observation during testing is both the red ENGINE FIRE warning and the amber FIRE DETECT CAS message.