Powerplant

Question 1

Type of engine

Answer 1

General Electric CF34-8C5

-High bypass turbofan controlled by a full authority digital engine control system (FADEC)

Question 2

N1

Answer 2

Fan Rotor

Question 3

N2

Answer 3

• Compressor rotor
• Ten stage axial flow compressor
• Also composed of a…

Question 4

Core air percentage

Answer 4

20%

Question 5

Bypass air

Answer 5

80%

Question 6

Engine thrust

Answer 6

Normal TO 13,360lbs
Max takeoff thrust (APR) 14,510lbs
Max continuous 13,680lbs

Question 7

N1 fan

Answer 7

-Single stage fan consisting of 28 titanium allow blades

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Question 8

N2 compressor

Answer 8

-A 10 stage variable geometry (VG, variable AOA, controlled by FADEC using high pressure fuel to move pitch of the compressor blades) axial flow…

Question 9

N2 accessory gearbox

Answer 9

N2 compressor drives the accessory gearbox powering the following items (FISH OIL +)

• Fuel pump (engine driven high pressure fuel pump)
• IDG
• Starter
• Hydraulic pumps
• oil pump
• FADEC alternator (+)

Question 10

High pressure engine driven fuel pump

Answer 10

…

Question 11

Fuel/oil heat exchanger

Answer 11

…

Question 12

Fuel Filter

Answer 12

…

Question 13

Fuel metering unit (FMU)

Answer 13

• Works with the FADEC to increase or decrease the fuel flow to meet the conditions
• Not mechanically linked to the thrust levers

Question 14

Full authority digital engine control (FADEC)

Answer 14

• Fuel control
• Compressor airflow management
• Engine starting and ignition control

Question 15

FADEC unit

Answer 15

Each engine has its own unit.

• Each unit has two channels
• Active channel switches every second engine start.
• When N2 is above 50%, the FADEC alternator supplies power to both channels (No outside power is required)

Question 16

FADEC and engine idle

Answer 16

FADEC choosing among the 5 best idle settings
-flight ide
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Question 17

Flight idle

Answer 17

Landing gear is up or…

Question 18

Approach idle

Answer 18

The N2 core speed that permits the engine to accelerate to go-around thrust in the minimum time.
-Activates when thrust levers at idle and gear down or flaps>20º

Question 19

Landing idle

Answer 19

Increase N2 to allows reverse thrust in the minimum time.

• Occurs at weight on wheels or wheel rotation
• N2 stays elevated for 5 seconds waiting for reverse thrust before going to ground idle

Question 20

Reverse Idle

Answer 20

…

Question 21

Ground idle

Answer 21

Minimum N2 thrust setting on the ground ( somewhere in the 55-65%)
-…

Question 22

One-engine-only (OEO) fuel scheduling

Answer 22

Occurs when N1’s are 15% different or more

…

Question 23

Automatic performance reserve (APR) thrust

Answer 23

• Armed when during takeoff when N1 is within 8% of scheduled takeoff thrust (Normal or flex) on both engines
• No EICAS message when APR arms
• …
• APR also activates when thrust reverses are set to MAX POWER detent.

Question 24

Power plant ignition system

Answer 24

Ignition A powered by the AC essential bus
Ignition B powered by battery
…

Question 25

When will you get a HOT indication on the ITT gauge?

Answer 25

905ºC