Engines

Question 1

Engine Types

Answer 1

GE CF34-10E high bypass ratio dual rotor turbofan

Question 2

Igniter Knob in Off position

Answer 2

• deactivates ignition on the ground

- FADEC disregards Off position in flight

Question 3

How does fuel flow from the fuel tank to the fuel injectors?

Answer 3

• Fuel exited tank via ejector pumps —> Low Pressure Fuel Pump —>
  A) High Pressure Fuel Pump —> Fuel tank return
  B) Heat Exchanger —> Hight Pressure Fuel Pump —> Fuel Filter —> FMU —> fuel injectors

Question 4

When does the FADEC energize both ingniters

Answer 4

• engine air start
• engine flame out
• missed light off
• cold soak condition on the ground
• high alt airport ground start
• selector OVRD

Question 5

When should an auto-relight be considered unsuccessful

Answer 5

• engine relight does not occurs within 30 secs

- N2 falls below 7.2%

Question 6

Components of Engine Control System

Answer 6

• FADEC
• Thrust Levers
• T2 sensors
• N1 sensors

Question 7

What do T2 and N1 sensors provide?

Answer 7

• T2 sensors monitor engine inlet temp for use by FADEC

- N1 sensors provide Fan Speed data for FADEC and airplane vibration monitoring

Question 8

Function of the FADEC

Answer 8

• 2 channels (in-control channel switch after each engine start)

– Engine protection;
– Control of the requested and max N1;
– Control of the ATTCS

Question 9

What powers the FADEC

Answer 9

• PMA above 50% N2

- Airplane electrical system below 50% N2 and as backup

Question 10

ATTCS activation logic

Answer 10

RSV automatically commanded when TL as TOGA and:

– Difference between both engine N1 values is greater than 15%; or
– One engine failure during takeoff; or
– One engine failure during go-around; or
– Windshear detection

*auto armed for go-around

Question 11

Min Flex takeoff thrust

Answer 11

• 75% maximum rated takeoff thrust; or
• CLB-2 + 1% N1

(Whichever is higher)

Question 12

When is GA mode activated

Answer 12

• inflight
• landing gear down
• flaps down
• thrust mode other than takeoff
• TL set to TOGA

Question 13

Approach Idle activation

Answer 13

• allows rapid acceleration to GA thrust

– In flight;
– Altitude less than 15000 ft; and
– Flaps 1 or greater or landing gear down

Question 14

Final Approach thrust activation

Answer 14

– Altitude lower than 1200 ft AGL;
– Landing flaps;
– Landing gear down

Question 15

Engine Protections

Answer 15

FADEC Start Protections:

• Hung Start
• Hot Start
• No Light Off

Overspeed Protection
- at 102% N2 FADEC commands engine shutdown

Overtemp Protection
- FADEC controls ITT limits throughout start and engine operation

Question 16

Min Oil level for takeoff

Answer 16

Oil level must be in the green range

Question 17

When does FADEC alternate exciters

Answer 17

After each start

Question 18

Engine indication during start

Answer 18

• ignition at approx 7% N2
• fuel flow at approx 20% to 25% N2
• light off
• starter cutout at 50% N2

Question 19

How are the thrust reversers controlled

Answer 19

• Electrically controlled via the FADEC
• Hydraulically actuated
• independently operated