Engine Fire Protection Flashcards
What types of fire detection systems are used for engine fire detection?
Overheat.
Rate of rise.
Flame detectors.
How does a thermal Switch fire protection system operate?
When heated past a predetermined temperature, the switch closes, causing the warning devices in the cockpit to activate.
How many thermal switches are needed in a thermal switch fire protection system?
At least one
What kind of fire detection system allows more complete coverage than a spot type system?
A continuous loop system
What happens if an engine equipped with a thermocouple fire warning system overheats slowly?
Nothing, because a fast temperature rise or rapid heating is required for this type of fire system to operate.
What electrical power is required for a thermocouple fire protection system to operate?
Both the thermocouple produced power and the aircraft electrical system are required for this type of fire protection system to operate.
What is the likely cause of a false fire warning?
The fire sensing loop is bent or kinked excessively
What are fire extinguishing systems designed to do?
Dilute the oxygen levels around the engine to a point that does not allow combustion.
Reduce temperatures below the ignition point.
Describe how a Kidde and Fenwall continuous loop fire protection system functions:
A Kidde system has two conductors embedded in a thermistor material.
A Fenwall system has one conductive wire, surrounded by ceramic beads.
When heated the ceramic beads or thermistor material resistance drops, allowing current to flow.
What elements must be present for a fire to occur?
Ignition source (heat or spark).
Fuel.
Oxygen.
What group of fire extinguishing agents are no longer manufactured because of environmental concerns?
Halons (Freon or CFCs).
Not manufactured since 1995.
How are fire extinguishing agents distributed?
Through perforated tubing, and/or discharge nozzles
What is the purpose of the discharge cartridge and how is it activated?
The discharge cartridge, or squib, which is electrically ignited, fires a projectile into the frangible disk, thereby releasing fire extinguishing agent. 
How is a fire extinguisher system with a high rate of discharge classified?
As an HRD fire extinguisher system
What do the red and yellow discs in a fire extinguishing system indicate?
Yellow disc - normal discharge.
Red disc - thermal discharge.
