Power Plant

Question 1

Broad engine overview

Answer 1

Axial flow, geared fan, concentric twin-spool, FADEC controlled, and ultra-high bypass ratio turbo fan.

Question 2

What type of thrust reverser system?

Answer 2

Cascade. Blocker doors to state into place when translating sleeves move aft, redirecting air through the cascades.

Question 3

What allows the fan blades to rotate slower then the N1 shaft and what is the benefit?

Answer 3

Fan drive gear system, fan spins 3 times slower then the N1 shaft. More efficient when both operating at their own optimum speeds.

Question 4

N1 shaft overview

Answer 4

-drives FDGS
- 3 stage low px comp that is powered by the 3 stage low px turbine.

Question 5

N2 shaft overview

Answer 5

2 stage high px turbine.

Drives 8 stage high px compressor and Eng main gearbox.

Question 6

How much thrust does the bypass flow generate?

Answer 6

80%

Question 7

What does the main (accessory) gearbox drive?

Answer 7

• hyd EDP
• oil lubrication and scavenge pump
• VFG
• PMAG
• integrated fuel pump and control

Also used to transfer torque from air turbine starter to crank Eng during start.

Question 8

When will the EEC abort a start on ground?

Answer 8

• N1 locked rotor
• hot or hung start
• loss of EGT data
• igniter failure
• fuel control failure