STARTING AND IGNITION Flashcards
(27 cards)
What is the ignition and fuel supply controlled by?
Engine start level
What are the 3 main positions of the thrust reverser?
Normal (stowed) Reverse idle (used to activate) Full reverse (increase engine power)
When is continuous ignition activated in modern aircraft?
When there is a risk of flame out.
What does the igniter plug and igniter exciter do?
Plug- creates spark
Exciter- generates high voltage
How do you know if the HP fuel valve is open?
By the fuel flow indication, exhaust gas temp or fuel used as it is not indicated directly.
How many ignition systems does each engine have?
2 (named A and B)
One system always supplied by emergency power system of aircraft.
How is the immersion depth adjusted for igniter plug?
Using spacers.
Igniter bushing pre-adjusted with spacers
What is the insulator made of in igniters if there are 2 blue rings?
Beryllium oxide (toxic)
What material are modern non-toxic igniter plugs’ insulation?
Ceramic. (Inflexible)
What material is the internal wire of the ignition lead?
Copper.
Covered by silicon rubber insulator
What would a hot igniter lead result in?
More resistance and lower energy spark.
How are starter systems powered?
Pneumatically or electrically.
How long does the engine speed increase for after the starter assistance has been switched off?
Until it reaches idle
Always higher than self sustaining speed
What are the stages of engine start up?
Compressor moves from accessory gearbox Igniter on High pressure fuel on Light up Self sustaining speed Starter cut out speed Idle speed
Where can bleed air be used from to start the engine?
APU, another engine or ground cart.
How usually is a starter shut off valve operated?
Electrically controlled by a solenoid and Pneumatically operates by air pressure from the starter duct.
What type of valve is the fuel shut-off?
Electric motor driven valve
When will the HP valve open or close?
Opens when handle is moved up, visa versa
How is the LP fuel valve controlled on most modern airbus?
Engine master switch
What direction will thrust and reverse thrust rotate the mechanical drum?
Thrust - anti-clockwise
Reverse - clockwise
What other system does the thrust control system provide info to?
Fuel control unit
Where are taco and pinion transmissions usually found?
Thrust control drum in the pylon
What will stop the throttles moving due to vibration, but will allow pilot input?
Friction lock
What microswitches can be activated depending on thrust lever position?
- take off warning
- cabin pressurisation
- thrust reverser activation
