M15.13

Question 1

What are the three main engine controls?

Answer 1

• engine start controls
• forward thrust controls
• reverse thrust controls

Question 2

What is the start switch used for?

Answer 2

To switch fuel on and off and to switch ignition on during engine start

Question 3

What happens when the reverse thrust lever is pulled upwards?

Answer 3

The reverse thrust equipment on the engine is deployed

Question 4

What happens when the thrust reverse lever is pushed downwards?

Answer 4

The thrust reverser equipment is stowed away

Question 5

What does the engine start lever turn on?

Answer 5

The ignition and fuel supple to the combustion chamber

Question 6

How is fuel supplied?

Answer 6

Via a high and low pressure shut-off valve

Question 7

What type of valve is the low pressure fuel shut-off valve?

Answer 7

An electric motor driven valve

Question 8

When would the low pressure fuel shut-off valve illuminate and when would it go off?

Answer 8

The light illuminates when the valve is closed and goes out when the valve is open.

Question 9

When would the high pressure fuel shut-off valve open?

Answer 9

It opens and closes in conjunction with the engine start lever

Question 10

what does the mechanical thrust control system transmit?

Answer 10

The thrust lever input signals to the fuel control unit on the engine

Question 11

What are the forward thrust levers also called?

Answer 11

The throttles

Question 12

What are the main positions for the thrust levers?

Answer 12

Idle and take-off

Question 13

Where is the thrust reverse levers located?

Answer 13

At the top of the forward thrust lever

Question 14

What are the main positions of the reverse thrust levers?

Answer 14

Idle and full reverse thrust

Question 15

Where area rack and pinions found?

Answer 15

At the thrust control drum in the engine pylon and at the fuel control unit

Question 16

Why is a friction brake used in the forward thrust controls?

Answer 16

To keep the throttle control system in a selected position

Question 17

What are the three positions for a mechanical and electrical reverse thrust?

Answer 17

• the normal position (stowed)
• reverse idle (activate reversers)
• full reverse throttle (increase engine power)

Question 18

What is the throttle interlock system used for?

Answer 18

It stops the thrust being adjusted while the reverse thrusters are deploying or stowing

Question 19

How many separate thrust control signals are sent to the control unit from the control levers?

Answer 19

2 due to safety reasons

Question 20

How many resolvers are there for each thrust control lever?

Answer 20

2

Question 21

What is the job of a resolver?

Answer 21

To convert angular direction of the input lever to an electrical signal

Question 22

What is the job of the thrust lever lock system?

Answer 22

It makes sure that the forward thrust lever and the reverse thrust lever cant be used at the same time

Question 23

What is start ignition?

Answer 23

When the ignition is only used for start up of the engine

Question 24

What is continuous ignition?

Answer 24

When the engine has harsh external conditions that could lead to a flame-out of the combustion

Question 25

Why does each engine have two ignition systems?

Answer 25

For safety reasons

Question 26

When is the two ignition system used?

Answer 26

- one of the systems is supplied from emergency power - one of the systems is used during start ignition - both is used for continuous ignition

Question 27

What part of the ignition system should you never touch?

Answer 27

The output of the ignition exciter including the igniter lead contacts

Question 28

Where are the igniter plugs located in the combustion chamber?

Answer 28

Below the centre line

Question 29

When would you adjust the immersion depth of the igniter plug?

Answer 29

When the bushing must be changed

Question 30

What do two blue rings on igniters indicate?

Answer 30

That the igniter is made of beryllium oxide which is toxic (don’t touch with bare hands)

Question 31

What type of wire is used inside of ignition lead?

Answer 31

A copper wire

Question 32

What type of insulation is used in a igniter lead?

Answer 32

Silicon rubber

Question 33

Why is the igniter lead air cooled?

Answer 33

When the copper wire increases temperature the resistance also increases

Question 34

What are the two systems for gas turbine engine starts?

Answer 34

Electrical and pneumatic (APU is the only electrical start)

Question 35

What is a start system used for?

Answer 35

To get the necessary conditions which is need in the combustion chamber

Question 36

When does the engine starter switch off?

Answer 36

When the engine has started and goes passed the self sustaining speed

Question 37

Where is the starter shut-off valve located?

Answer 37

The lower area of the engine