Definition
A fire and overheat warning system that uses a long sensing element — typically a thin, heat-sensitive wire or tube routed as a continuous loop — through fire-prone areas of the aircraft, such as engine compartments. The element's electrical properties change when any part of it is exposed to a preset temperature or rate of temperature rise, triggering a warning in the cockpit. Common types include thermistor-based (Kidde, Fenwal) and pneumatic (Lindberg) systems.
Plain English
A long heat-sensing wire or tube that loops through areas where a fire could start. If any section gets too hot, the wire reports it and a warning light or alarm comes on in the cockpit.
Context Anchor
Seen in aircraft maintenance, engine fire warning systems, and inspection of protected areas such as engine compartments and other enclosed fire zones.
Derivation
Continuous-loop describes the sensor's physical layout — a single unbroken length running in a loop, so heat anywhere along it sets off the alarm. This contrasts with spot-detector systems, which only sense heat at fixed individual points.
Why Pilots Care
It gives early warning of fire or overheat so the crew can shut down the engine or take other action before damage spreads.
Analogy
Think of it like a long string of holiday lights wired so that heating any part of the string trips the breaker. You don't need a sensor at every bulb — the whole string is the sensor.
Intuition Check
Do not picture a row of separate smoke alarms. In this term, “continuous-loop” means the heat-sensing part runs as a connected path through the area it protects.
Example Sentence 1
During the preflight check, the crew tested the continuous-loop fire-detection system and confirmed the engine fire warning light illuminated when the test switch was pressed.
Example Sentence 2
After landing the pilot noted a fault light and traced it to a damaged section of the continuous-loop fire-detection system in the right nacelle.