Crj Engines

Question 0

How much will apr increase thrust.

Answer 0

App. 2%

Question 1

What is the thrust output?

Answer 1

8729 lbs

Question 2

Where does thrust reversing come from?

Answer 2

Bypass n1 air

Question 3

How does the turbine engine work?

Answer 3

N1 air enters the n2 core where it is compressed mixed with fuel and ignited. The resulting combustion gas are then exhausted through the high pressure two stage n2 turbine which drives the n2 assembly. The exhaust gases are then discharged onto the low pressure four stage n1 turbine to drive the n1 fan.

Question 4

What does the variable geometry compressor do? Vg

Answer 4

Improves fuel efficiency of the compressor by optimizing the air flows angle of attack at the compressor blades and protects the compressor from stall and surge damage.

Question 5

What does the accessory gearbox drive. And what is it driven by?

Answer 5

Oil pumps
Hydraulic pump
Fuel pump and fuel control unit
Idg

Mounted on gearbox is the ats

Driven by n2 compressor

Question 6

What does the fcu do?

Answer 6

Provides correct amount of fuel for thrust position. Provide initial fuel for oil heat exchanger.

Question 7

How can fuel be interrupted?

Answer 7

Ng fire push light

Thrust to shutoff

Question 8

What does the fuel pump do?

Answer 8

3 pumps in one housing. Provides fuel at a flow rate that exceeds requirements of engines. Pump pressure also generates motive flow for scavenge and main ejectors.

Question 9

How is a blocked fuel filter depicted? What happens to fuel flow?

Answer 9

Pictorially on synoptic page and as a caution message on eicas.

Question 10

What does the fuel control unit do. Fcu?

Answer 10

Meters fuel at low rpm and controls and actuated vg inlet guide vanes. At high rpm fuel is controlled by the n1 amplifier.

Question 11

What do the dc pumps and main ejectors do.?

Answer 11

Dc pumps provide fuel flow for start and low pressure this initiates motive flow.
Main ejectors provide continuous flow to engines.

Question 12

What is n2 speed control?

Answer 12

At low power settings the fcu hydro mechanically controls the n2 speed
Matched movement of the thrust should pride matched n2 rpm. N1 and itt indications may very.

Question 13

What is n1 speed control?

Answer 13

At takeoff climb and cruise power the n1 amplifier controls rpm. Trims to achieve desired rpm. This happens above 79% n1 and should match n1 speeds. This is desirable especially for takeoff

Question 14

What happens if the engine speed switches are moved to the off position when high power is set.

Answer 14

Rapid increase in engine rpm will occur and itt limits may be exceeded.

Question 15

What does the start valve do? How is it operated?

Answer 15

Controls amount of air to starter closes around 55% n2

Via the start stop switch

Question 16

How are the igniters powered.

Answer 16

A-ac

B-dc

Question 17

What does it take for apr to activate(produce power)?

Answer 17

A significant loss of n1 power in either engine

Question 18

When do n1 and n2 vib indicators appear?

Answer 18

N1 after normal oil pressure is established

N2 when vibration is detected.

Question 19

On the pa panel what happens in the cabin when emer is pushed?

Answer 19

Red light on overhead exit, and at fa handset cradle the amber emg light flashes.

Question 20

When an rtu becomes iNop how can you tune it?

Answer 20

By inhibiting it on the standby com and using the 1/2 switch to tune.