Jeppesen Oral- Chapter 11 (Fire Protection) Flashcards
oVERHEAT, RATE OF RISE, FLAME DETectors
When heated past a predetermined temperature, switch closes and activates system
at least one
Continuous loop system
Nothing. Fast temperature rise is required for this system to operate
Both the thermocouple produced power and the aircraft electrical system
The engine fire sensing loop is bent of kinked excessivly
Dilute oxygen levels around the engine to a point that does not allow further combustion, or reduce temperatures below ignition, flash point
Kiddie- sensing element consisting of a sealed inconel tube containing two conductors that are embedded in a thermistor material. One wire is grounded to the outer tube at each end and acts as an internal ground and the other is a positive lead. When fire overheat occurs, the thermistor resistance drops and allows current to flow between the two wires Fenwal- sensing elements consisting of small diameter flexible inconel tube containing a single wire electrode surrounded by ceramic beads. These beads prevent electrode and tube from touching each other. Current is applied to the electrode while the outer tube is grounded to the aircraft structure. When fire occurs, the core resistance of the ceramic beads drops, allowing current to flow
Ignition source, fuel, oxygen
Halon (freon or chlorofluorocarbons [CFC]
Through perforated tubing and or discharge nozzles
Discharge cartridge or squib is electrically ignited, fires a projectile into the frangible disk, thereby releasing fire extinguishing agent
As a HRD fire extinguisher system
Yellow- normal discharge Red- thermal discharge
