Engines

Question 1

The N1 rotor consists of what three items?

Answer 1

1. N1 Fan
2. Low pressure compressor (booster)
3. Four-Stage low pressure turbine

Question 2

What is the primary (used for combustion) vs. bypass air split?

Answer 2

20% primary / 80% bypass

Question 3

The N2 rotor consists of what two items?

Answer 3

1. The Nine-stage HP compressor
2. High Pressure single-stage turbine

Question 4

The accessory drive is powered (i.e. turned) by what?

Answer 4

The high pressure turbine

Question 5

What items are on the accessory drive?

Answer 5

1. Oil Scavenge Pump
2. Engine Fuel Pumps
3. IDG (Integrated Drive Generator)
4. Starter
5. Hydraulic Pump

Question 6

What powers the EEC’s ?

Answer 6

Dedicated engine-driven alternators that are independent of the airplane’s electrical system

Question 7

T/F: The ENGINE CONTROL Lights only operate on the ground and illuminate when there are engine control system faults.

Answer 7

True

Question 8

When does the EEC set Approach Idle in flight?

Answer 8

When the flaps are in the landing configuration or if engine anti-ice is ON for either engine.

Question 9

The reverse thrust lever is blocked at the Interlock position until the __________ have approached the deployed position.

Answer 9

reverser sleeves

Question 10

What happens when the Engine Start Levers are placed to IDLE during engine start?

Answer 10

1. The ignition system is energized through the EEC
2. The spar fuel and engine fuel shutoff valves are electrically opened to introduce fuel

Question 11

The left ignitor plug receives power from ?

Answer 11

Associated AC Transfer Bus

Question 12

The right ignitor plug receives power from?

Answer 12

The AC Standby Bus (For this reason, if an engine is started with battery power only, the right igniter must be selected)

Question 13

T/F: The EEC turns on the ignition system automatically if the EEC senses a possible engine flameout condition.

Answer 13

True

Question 14

When should Engine Ignition be on?

Answer 14

1. Takeoff
2. Landing
3. Operation in Heavy Rain
4. Anti-Ice operation
5. Severe turbulence

Question 15

The engine starting system uses ________ to turn the engine’s N2 rotor during a start

Answer 15

pneumatic power

Question 16

What minimum N2 value should be observed before placing the start lever to IDLE?

Answer 16

20 % N2 (25% is recommended)

Question 17

What is the definition of Max Motoring (N2) ?

Answer 17

N2 acceleration less than 1% rise in approximately 5 seconds

Question 18

What is starter cutout speed?

Answer 18

Approximately 56% N2

Question 19

What happens at Starter Cutout speed?

Answer 19

The ENGINE START switch automatically returns to OFF, the bleed air valve opens, and the start valve closes.

Question 20

What is considered a Wet Start?

Answer 20

A wet start occurs if the EGT does not rise after the Start Lever is moved to IDLE.

Question 21

T/F: The EEC provides the same start protection during in-flight starts as it does for ground starts.

Answer 21

False

Question 22

T/F: Taxi operations, at or near idle, apply to the engine cool down times

Answer 22

True

Question 23

The EEC is comprised of what two channels?

Answer 23

Active & Standby

Question 24

If the EEC normal mode is not available, the EEC downgrades to what mode?

Answer 24

Soft alternate mode

Question 25

Placing the ENGINE START switch to FLT provides ignition to _________

Answer 25

both ignitors

Question 26

The N1 Fan and booster combined act as a _________ compressor

Answer 26

4 stage

Question 27

The thrust reversers can be deployed when either radio altimeter senses less than _____ altitude, or when the _________ is in ground mode

Answer 27

10 feet; air/ground sensor

Question 28

The EGT readout will blink on and off when...

Answer 28

EEC senses a condition that may lead to a hot start

Question 29

Each engine has ______ igniter plugs that operate ____________

Answer 29

2; independently

Question 30

The _____________ lights only operate ____________ and indicate that the aircraft is not to takeoff due to engine control system malfunctions.

Answer 30

ENGINE CONTROL; on the ground (below 80kts prior to t/o; or ~30 seconds after touchdown)

Question 31

The EEC uses N1to set thrust in one of what 2 modes?

Answer 31

Normal & Alternate

Question 32

At the same airspeed and altitude, N1 and N2 RPM will be _______ for approach idle than for flight minimum idle.

Answer 32

higher (reduces engine acceleration time in the event of a go-around)

Question 33

During ground starts, the EEC monitors engine parameters to detect:

Answer 33

1. Impending hot starts 2. EGT start limit exceedances 3. Wet starts

Question 34

What kind of engines does the B737 have?

Answer 34

CFM56-7 high bypass, dual rotor, axial flow turbofan engines

Question 35

The EEC interfaces with which engine components?

Answer 35

Hydromechanical Unit (fuel metering), Engine Air control systems (stator vanes and bleed air valves), Fuel flow transmitters, Ignition & Starting systems, Thrust Reversers

Question 36

Both ON and ALTN are visible on the EEC Switch. What mode is the EEC in?

Answer 36

It has automatically switched to the Soft Alternate mode.

Question 37

What are two ways of manually selecting the Hard Alternate mode on the EEC?

Answer 37

1. Retarding the thrust lever to idle when in the soft mode 2. Manually selecting ALTN on the EEC switch

Question 38

What is the difference between the Hard alternate and Soft alternate modes of the EEC.

Answer 38

The Hard mode will always provide greater than or equal to thrust than the normal mode. The Soft simply uses the last valid flight conditions to define engine parameters.

Question 39

T/F: The reverse thrust lever is blocked at the interlock position until the reverser sleeves have approached the deployed position

Answer 39

True

Question 40

What conditions must be met for the reverse thrust lever to be used?

Answer 40

The forward thrust lever must be in the full idle position, with the radio altimeter less than 10 feet or air/ground sensor in the ground mode.

Question 41

Regardless of Ignition Selector switch position, placing the ENGINE START switch to ___________ provides ignition to both igniters continuously

Answer 41

FLT (flight)

Question 42

How are the left and right ignitor plugs powered?

Answer 42

Left - associated AC Transfers Bus Right - AC Standby Bus (Right ignitor must be selected when starting with battery power only)

Question 43

What happens when starter cutout speed (~56% N2) is reached during an engine start?

Answer 43

The ENGINE START switch automatically returns to OFF, the bleed air valve opens, and the start valve closes