Chapter 6: Engines

Question 1

Engine Make and Model

Answer 1

General Electric CF34-8E

Question 2

Start/Stop 1(2)—STOP

Answer 2

Shuts down respective engine if TLA idle in flight, <5 deg on ground (EICAS message if not idle)

Question 3

Ignition Switch—OFF

Answer 3

In flight, FADEC ignores OFF position; On ground, FADEC deactivates igniters and inhibits fuel flow

Question 4

FADEC Power Source

Answer 4

PMA (Permanent Magnetic Alternator) if N2>~50%, Aircraft electrical system otherwise

Question 5

ATTCS Commands RSV Power when:

Answer 5

TLA TOGA Position and…

• N1 Difference > 15%
• Engine Failure during Takeoff
• Engine Failure during Go-Around
• Windshear Detection

Question 6

N1 Wing Anti-Ice Cyan Line

Answer 6

Indicates minimum N1 required for bleed requirements during final approach (radio alt. <1,200’)

Question 7

Describe Fuel Flow from Tanks to Engine

Answer 7

After leaving tanks, fuel passes through engine-driven low-pressure fuel pump and splits into two paths. The first path goes through the engine-driven high-pressure fuel pump and is routed to the ejector pumps. The second goes through the fuel/oil heat exchanger, fuel filter (in the FMU), then returns to the engine-driven high-pressure fuel pump and is routed to the FMU, then the fuel injectors.

Question 8

Fuel/Oil Heat Exchanger

Answer 8

Maintains oil within an acceptable temperature range and heats fuel to prevent freezing

Question 9

FMU (Fuel Metering Unit)

Answer 9

• Meters and distributes fuel to the injectors
• Controls shutoff valve for normal shutdowns
• Provides engine overspeed protection

Question 10

Variable Geometry Actuator

Answer 10

Controlled by FADEC via the FMU, fuel-driven actuators adjust position of stators to optimize efficiency of compressor for corrected N2 speed

Question 11

Describe the Lubrication System

Answer 11

One supply pump, 4 scavenge pumps
Oil filter with bypass and cold start relief valve
Oil lubrication pump -> Filter -> Fuel/Oil Heat Exchanger -> divides into 4 circuits (A,B,C,AGB)

Question 12

Starting System Components

Answer 12

Starter Control Valve

Air Turbine Starter

Question 13

Ignition System

Answer 13

Two igniters per engine A/B
B igniter powered by respective AC BUS, commanded by SPDA 2
A igniter powered by AC STBY BUS, (commanded by SPDA 1)

One igniter energized for ground starts, both for air starts or if switch in OVRD position

Question 14

Ground Start Sequence

Answer 14

Starter Valve Opens
~7% N2: Ignition is energized
~20% N2: Fuel flow initiated
~50% N2: Starter cutout and FADEC commands FMU to produce ground idle speed

Both igniters energized if no light off 15s after FF, must be aborted if no light off 30s after FF

Question 15

Air Start Sequence

Answer 15

~7% N2: Both igniters energized
~20% N2 OR 15s: Fuel flow is initiated
~50% N2: Starter cutout and FADEC commands FMU to accelerate engine to flight idle

No hot or hung start protection, must be aborted if no light off 30s after FF

Question 16

Windmill Start Sequence

Answer 16

7% N2: Both igniters are energized
7.2% N2 or 15s: Fuel flow is initiated

No hot or hung start protection, must be aborted if no light off within 30s of FF

Question 17

Auto Relight

Answer 17

WML is displayed, FADEC commands relight fuel flow, both igniters energized
In flight: Must be MANUALLY aborted if >30s or N2 < 7.2%
On Ground: Automatically aborted if N2 < 52%

Question 18

Thrust Reverser After Engine Failure

Answer 18

Available on respective engine for 30s
Moving both TLA to MAX REV commands MIN REV
Moving ONLY operative TLA to MAX REV commands MAX REV

Question 19

Minimum Flex Takeoff Thrust

Answer 19

The higher of 75% of max rated thrust or TO-2 + 0.5% N1

Question 20

When will CLB-1 selection be inhibited on the ground?

Answer 20

If CLB-1 N1 is greater than takeoff thrust

Question 21

Idle Thrust Selections

Answer 21

Ground
Flight
Approach (<15,000’, flaps or gear deployed)
Final Approach (Radio alt. <1,200’, landing flaps, gear down)

Automatic increase of flight and approach idle in icing conditions; no automatic increase for final approach idle, but N1 cyan tick is displayed

Question 22

TO-1 Thrust Rating

Answer 22

TO-1: 13,000 lbs
TO-1 RSV: 14,200 lbs

ISA and Sea Level

Question 23

TO-2 Thrust Rating

Answer 23

TO-2: 11,800 lbs
TO-2 RSV: 13,000 lbs

ISA and Seal Level

Question 24

GA Thrust Ratings

Answer 24

GA: 13,000 lbs
GA RSV: 14,200 lbs

ISA and Sea Level

Question 25

CON Thrust Rating

Answer 25

CON: 12,800 lbs

ISA and Sea Level

Question 26

CLB-1 Thrust Rating

Answer 26

CLB-1: 12,400 lbs

ISA and Sea Level

Question 27

CLB-2 Thrust Rating

Answer 27

CLB-2: 11,100 lbs

ISA and Sea Level

Question 28

CRZ Thrust Rating

Answer 28

CRZ: 10,400 lbs

ISA and Sea Level

Question 29

FADEC Protections

Answer 29

On the ground: Hot start, hung start, no light off

In the Air: Overspeed protection if N2 > 102%, FADEC commands shutdown. Will not relight if 3 overspeeds within 30s

Question 30

Engine Start with High ITT

Answer 30

FADEC inhibits fuel flow if ITT > 120 C