15.20 - Fire Protection Systems Flashcards
(11 cards)
Thermodynamics turbine failure.
Rapid build up of ice on inlet screens or inlet guide vanes can lead to severe overheating. Causing turbine blades to melt, be severed or be thrown outwards.
Generally caused by ice, excess air bleed or leakage, or faulty controls that permit a compressor stall or excess fuel.
Mechanical turbine failure.
Fractured or thrown blades.
Penetration of the turbine case is a fire hazard as is the penetration of fluid lines and hoses.
What can an improperly adjusted fuel nozzle lead to
Can give a high fuel flow which can cause a burn through of the exhaust cone.
What are the two most common types of engine fire detection systems
Spot detectors
Continuous loop detectors.
Spot detectors
Fire detection.
Thermal switch system, thermocouple system, optical fire detection system and the pneumatic fire detection system.
Thermal switch system.
Older a/c
Complete circuits at set temps.
Connected in parallel with each other but in series with the lights.
Thermocouple system
Depends on rate of temp change.
Optical fire detectors.
Aka flame detectors.
Infra-red type or ultraviolet type.
IR type used on used on light turboprop aircraft. And helicopter engines.
Pneumatic thermal fire detection system.
Helium filled probe connected at one end to a responder assembly.
The helium expands and triggers an internal switch.
Has an integrity switch in case of a leak.
Gives an average or discrete temperature.
Average temp sensing is done by helium
Discrete sensing is done by hydrogen filled core.
Fire detection control unit
Fire detection card
Control modules contain removable control cards.
Fire bottles.
Stainless steel
Pressurised by nitrogen
Spherical design is lightest weight, cyclindrical shapes used where space is a limiting factor.
