ENGINE

Question 1

ENGINE

Answer 1

General Electric CF34-10E (190/195)
•	Hi-bypass/dual-rotor turbofan
	10-stage compressor with variable geometry/2-stage HP turbine
	1-stage fan/4-stage LP turbine
•	Maximum thrust 20,000 pounds (190/195)

Question 2

Starting and Ignition System

Answer 2

•	ATS (Air Turbine Starter)
•	Two igniters per engine
•	Starter Control Valve
•	Each engine can be started via:
	*APU air
	*Crossbleed air (engine assist)
	*External air source (air cart or huffer cart)
	*Windmilling start (airborne only)

Question 3

The NORMAL start sequence:

Answer 3

• Fadec controlled
• For air starts the FADEC ignores an ‘OFF’ position selected on the ignition

ENGINE NORMAL SEQUENCE:

SELECT START > 7% N2 > 20% N2 F.FLOW LIGHT OFF WITHIN 5s > 50% N2 IGNITION OFF and STARTER CUT OUT.

Question 4

Thrust Reverser System

Answer 4

• Hydraulically actuated
• FADEC provides interlock protection against inadvertent deployment
• Idle thrust commanded if opened in flight
• For ground use only
• Idle thrust reverse is commanded while cowls are not totally deployed

Question 5

Engine FADEC

Answer 5

• ESS powered below 50% N2
• PMA powered above approximately 50%N2
• 1 installed for each engine
• Each FADEC has 2 channels (active and standby)

Question 6

ATTC (Automatic Takeoff Thrust Control Sys

Answer 6

• Controlled by the FADEC
Automatically provides maximum engine thrust (RSV) whenever it’s armed, thrust levers TOGA, and one of the following occurs:
Difference between N1 values > 15%
One engine failure during takeoff
engine failure during go-around
Windshear detection
• Automatically armed for normal go-around (GA) mode

Question 7

Engine Protection

Answer 7

• During engine start the FADEC will prevent:

* Hung start (inhibited in flight) – compressor not accelerating to generate required airflow
* Hot start (inhibited in flight) – insufficient airflow to keep ITT under control
* No light off – air and fuel, but no ignition

Question 8

Overspeed

Answer 8

• If N2 reaches 102% the FADEC commands an automatic shutdown
*In the event of three (3) consecutive shutdowns due to an overspeed within 30 seconds, the FADEC will not attempt a relight

Question 9

OVER TEMPERATURE

Answer 9

• FADEC will prevent fuel flow during ground start until ITT is at or below 120C
  * Automatically dry-motoring occurs and fuel flow is commanded with ITT below 120C

Question 10

After start stabilized engine parameters

Answer 10

N1: 27
ITT: 460
N2: 62
FF: 250 KGH
OP: > 25 PSI