M15.13 Flashcards
What are the three main engine controls?
- engine start controls
- forward thrust controls
- reverse thrust controls
What is the start switch used for?
To switch fuel on and off and to switch ignition on during engine start
What happens when the reverse thrust lever is pulled upwards?
The reverse thrust equipment on the engine is deployed
What happens when the thrust reverse lever is pushed downwards?
The thrust reverser equipment is stowed away
What does the engine start lever turn on?
The ignition and fuel supple to the combustion chamber
How is fuel supplied?
Via a high and low pressure shut-off valve
What type of valve is the low pressure fuel shut-off valve?
An electric motor driven valve
When would the low pressure fuel shut-off valve illuminate and when would it go off?
The light illuminates when the valve is closed and goes out when the valve is open.
When would the high pressure fuel shut-off valve open?
It opens and closes in conjunction with the engine start lever
what does the mechanical thrust control system transmit?
The thrust lever input signals to the fuel control unit on the engine
What are the forward thrust levers also called?
The throttles
What are the main positions for the thrust levers?
Idle and take-off
Where is the thrust reverse levers located?
At the top of the forward thrust lever
What are the main positions of the reverse thrust levers?
Idle and full reverse thrust
Where area rack and pinions found?
At the thrust control drum in the engine pylon and at the fuel control unit
Why is a friction brake used in the forward thrust controls?
To keep the throttle control system in a selected position
What are the three positions for a mechanical and electrical reverse thrust?
- the normal position (stowed)
- reverse idle (activate reversers)
- full reverse throttle (increase engine power)
What is the throttle interlock system used for?
It stops the thrust being adjusted while the reverse thrusters are deploying or stowing
How many separate thrust control signals are sent to the control unit from the control levers?
2 due to safety reasons
How many resolvers are there for each thrust control lever?
2
What is the job of a resolver?
To convert angular direction of the input lever to an electrical signal
What is the job of the thrust lever lock system?
It makes sure that the forward thrust lever and the reverse thrust lever cant be used at the same time
What is start ignition?
When the ignition is only used for start up of the engine
What is continuous ignition?
When the engine has harsh external conditions that could lead to a flame-out of the combustion
Why does each engine have two ignition systems?
For safety reasons
When is the two ignition system used?
- one of the systems is supplied from emergency power
- one of the systems is used during start ignition
- both is used for continuous ignition
What part of the ignition system should you never touch?
The output of the ignition exciter including the igniter lead contacts
Where are the igniter plugs located in the combustion chamber?
Below the centre line
When would you adjust the immersion depth of the igniter plug?
When the bushing must be changed
What do two blue rings on igniters indicate?
That the igniter is made of beryllium oxide which is toxic (don’t touch with bare hands)
What type of wire is used inside of ignition lead?
A copper wire
What type of insulation is used in a igniter lead?
Silicon rubber
Why is the igniter lead air cooled?
When the copper wire increases temperature the resistance also increases
What are the two systems for gas turbine engine starts?
Electrical and pneumatic (APU is the only electrical start)
What is a start system used for?
To get the necessary conditions which is need in the combustion chamber
When does the engine starter switch off?
When the engine has started and goes passed the self sustaining speed
Where is the starter shut-off valve located?
The lower area of the engine
