15.20 Fire Protection Systems Flashcards
(22 cards)
What are thermodynamic turbine failures cased by?
Caused by cooling airflow issues or fuel control problems, often due to ice, stalls, or leakage. Can melt blades.
What is the cause of emchanical turbine failures?
Blade failures or fractures that puncture components, leading to fire or overheating
What fire detection components commonly used?
Overheat detectors
Rate of temperature rise detectors
Flame detectors (optical)
What are fire system requirements?
No false alarms
Fast and accurate fire detection
Detection of reignition
Continuous indication
Electrical test from flight deck
Robust against fluids, vibration, heat
What is a fire zone?
An area in the aircraft designated to require fire detection/extinguishing equipment due to high fire risk.
What are the two main categories of fire detection systems?
Spot detectors
continouous loop systems
How does a thermal switch detector work?
It closes a circuit when a set temperature is reached, triggering a fire light.
What does a thermocouple detector measure?
The rate of temperature rise (not a steady overheat).
What do optical detectors respond to?
Infrared (IR) or ultraviolet (UV) radiation from flames.
How does a pneumatic detector detect fire?
Heated helium gas increases pressure and triggers a switch.
What does the titanium wire in some detectors do?
Releases hydrogen gas under high temperature, raising pressure further to trigger the alarm.
What are the two most common types of continuous loop systems?
Fenwal and Kidde
What materials are used in Fenwal and Kidde systems?
Fenwal uses eutectic salt; Kidde uses thermistor core.
How do continuous loops differ from spot detectors?
They offer full-area monitoring and average temperature sensing.
Whats the purpose of dual loop fire systems?
To reduce false alarms – both loops must agree before warning.
What does automatic self interrogation do?
Tests the backup loop automatically if a fault is detected.
What extinguishing agent is most commonly used?
Halon 1301 – effective, low-toxicity, clean, and non-corrosive.
What is a squib in fire extinguishing systems?
An explosive cartridge that bursts the discharge valve disc to release agent.
What do the red and yellow discs indicate?
Red = automatic thermal discharge; Yellow = manual crew discharge.
What prevents backflow in 2-shot systems?
A two-way check valve.
What fire extinguishing sytems must transport aircraft have?
2 shots system (main + reserve)
Wheat happens when the fire switches in the flight deck are activated?
Closes fuel valve
Arms extinguishing system
Shuts down the affected engine
