Engines

Question 1

Model number and basic setup of the engine:

Answer 1

CFM 56-7
N₁: Fan + 4 stage LP Compressor - 4 Stage Turbine
N₂ 9 Stage HP Compressor - 1 Stage HP Turbine
CFM 56-7B24 (-700) 24k Thrust
CFM 56-7B27 (-800) 27k Thrust

Question 2

What are the EECs?

How are they powered?

Answer 2

Electronic Engine Control

Independent Alternator

Question 3

What is Normal EEC control vs. Soft Altn vs Hard Altn?

Answer 3

ON: Commands N₁ based on sensed flight conditions
Soft: Commands N₁ based on last valid flight parameters
Hard: Commands N₁ based on a fixed schedule

Question 4

What are the engine IDLE modes, and when are they commanded?

Answer 4

Ground
Flight
Approach - Flaps or Anti-Ice ON

Question 5

What items are on the accessory drive?

Answer 5

IDG
Starter
Hydraulic Pump
Oil Pump
Engine Fuel Pump

Question 6

What does the Green or Amber REV indicate?

Answer 6

Amber: Reverser is in transit / unlocked
Green: Reverser is deployed

Question 7

Power source for Ignitor L / R

Answer 7

L: onside AC Transfer Bus
R: AC Standby Bus

Question 8

Engine Start:
GND
OFF
CONT
FLIGHT

Answer 8

GND: Engine starter turns engine: START VALVE OPEN
OFF: Igniters off unless flameout sensed
CONT: Igniter (as selected) operates continuously
FLIGHT: Both igniters operate continuously

Question 9

EEC Auto protections

Answer 9

Hot Start
Wet Start (No Lightoff)
EGT Exceedence
* Ground Only

Question 10

REVERSER

Answer 10

Illuminates when reverser is commanded to stow