Engine fire protection systems Flashcards
What are the main categories of an engine fire protection system
Spot detection, continuous loop, flame detectors
Name examples of spot detection type systems
Thermal switch and thermal couple
Name examples of a continuous loop detection system
Fenwal, kidde, And pneumatic
When using thermal couple type fire detection systems, what happens if the engine overheat slowly
A thermal couple depends on the rate of temperature rise, and will not give a warning if the engine slowly overheat or a short circuit develops
How many thermal couples are required for an engine fire detection
Depends on the size of the fire zone and the total circuit resistance
Describe the operation of a kidde Continuous loop fire detector system
Has two wires in bedded in a special ceramic core with an inconel tube. One wire acts as an internal ground and the other wire is a hot lead that provides a current.When the ceramic core material heats up the resistance drops, completing the circuit between the internal wires, lighting a light
Where does a thermal couple fire detector system gets its electrical power to operate
The thermal couple produces power to close a relay, and power from the aircraft electrical system flows through the relay to the warning light
Describe a thermal switch fire detector system
Thermal switch system has one or more lights that are engaged by the aircraft electrical system when a heat sensitive thermal switch closes the circuit at the specific temperature
How are thermal switch is electrically connected in a circuit
Connected in parallel with each other but in series with a warning light
What is the most common cause of a false fire warning in a continuous loop detector system
Dents, kinks, crushed sensing elements.
Will a continuous loop fire detector still indicate the presence of a fire if the element is broken two
Yes
What two methods are used to discharge fire extinguishing agents
Mechanical and electrical
What method is used to release the fire extinguishing agent in a typical turbine engine fire protection system
Common method is to equip the fire extinguisher in containers with the discharge valves that are operated by electrically discharge cartridges. Squib
What method is used to determine the proper fire extinguisher container pressure
Check the container gauge to determine if the pressure is between the prescribed a minimum and maximum limit
What is the color marking used to identify fire extinguishing lines
Brown tag with black diamonds
What method other than the pressure gauge is used to indicate low agent pressure in a container
Some Aircrafts are equipped it with a low pressure warning light in the cockpit
What is the purpose of the yellow and red discharge plugs in the turbine engine fire extinguishing system
The yellow plug indicates a pilot initiated discharge. The red plug indicates thermal activated discharge
What are the two methods Commonly used to distribute the fire extinguishing agent to the engine
A perforated tube or discharge nozzle are used to distribute the agent
How does the fire extinguisher agent put out the fire
It dilutes the atmosphere so that it will not support combustion
What does HRD stand for
High rate of discharge
How is the fire extinguishing agent distributed from a HRD system
It is delivered from open end tubes
How long does it take to discharge the extinguishing agent in a HRD system
1 to 2 Seconds
Which type of fire detection system gives a more complete coverage to a fire hazard
Continuous loop system
