The engine fire warning system consists of a core element, a sensor tube, and which additional component?

The engine fire warning system is designed to detect high-temperature conditions that may indicate an engine fire. The core element, typically a sensing device, continuously monitors the environment around it. A sensor tube is used to detect temperature changes, but the system requires a means to alert the pilot to any potential fire hazards.

The responder assembly plays a crucial role in this warning system by receiving signals from the sensor tube. When the tube detects temperatures that exceed a preset threshold, the responder assembly activates the visual and/or audible warnings in the cockpit, thereby informing the crew of the engine fire condition. This immediate feedback is essential for ensuring that the pilot can take appropriate safety measures.

In contrast, other components listed, such as a temperature gauge, thermostat, or micro switches, do not fulfill the primary function of relaying a fire warning signal to the cockpit. A temperature gauge simply displays temperature readings, a thermostat regulates temperature but does not provide a warning system, and micro switches are typically used for other control functions rather than direct fire detection. Thus, the responder assembly is integral to the operation of the fire warning system, making it the correct answer.