Ultra violet flame detection

 

Three dual circuit detector assemblies were strategically placed within the nacelle to detect flame break-out from any point of combustion chamber circumference. As their tile suggests, they respond to UV light. Once again, both circuits must detect to signal a warning and, when necessary, signal circuit operation may be selected. There were problems with this detector during service, it was reliable and was replace by some additional lengths of fire wire.

 

Engine internal overheat

 

Thermal switches are located adjacent to bearings 2, 3, 4 and 5; any one will illuminate its ‘ENGINE OVERHEAT’ warning. Prompting engine shut-down. Turbine cooling air temperature is sensed and presented on a gauge at the flight engineer’s panel; a 640C thermal switch brings on the ‘ENGINE OVERHEAT’ warning.

 

Nacelle/wing overheat

 

This comprises a single fire wall loop in each nacelle adjacent to pressurisation bleed-air equipment and two thermal switches in a wing equipment bay above the engine. Any one of the three elements, sensing a hot air leak, will trigger a ‘NACELLE/WING OVERHEAT’ warning.

 

Engine fire protection

 

One fire extinguisher bottle is located in a wing equipment bay above each engine. Each bottle has two firing heads and is capable of discharging into its own, or the adjacent, engine bay. In the event of an engine fire, first the engine is shut down, then the engine’s own bottle discharged and if the fire still persists the adjacent bottle is used.

 

Fuselage smoke

 

Ten smoke detectors are strategically positioned within the fuselage adjacent to equipment zones and baggage holds. During Concorde’s service life, toilet smoke detectors became mandatory and were fitted to all Concordes in 1987