Engines

Question 1

What percentage value passes through the core of the engine?

Answer 1

52%, the other 48% is around the engine.

Question 2

What is the purpose of the Anti-Surge Bleed System is it automatic?

Answer 2

It is automatic.
Prevent compressor stall during initial acceleration
Air in acceleration of the engine rotor during start.

Question 3

Which compressor is the low compressor and how many stages does it have?

Answer 3

N1 and it comprises the first 6 compressor stages.

Question 4

Which compressor is the high compressor stage and how many stages does it have?

Answer 4

N2 and it comprises the last 7 compressor stages.

Question 5

What is the Starter Duty Cycle?

Answer 5

90 seconds ON, 5 min OFF, 30 seconds ON, 5 min off. (May continue indefinetely).

Question 6

What is the Ignition Duty Cycle?

Answer 6

10 minutes ON, 10 minutes OFF.

Question 7

Losing N2 RPM sense input to the Fuel Control will cause what engine reaction?

Answer 7

The engine will default to takeoff RPM.

Question 8

Losing Ps4 input to the Fuel Control will cause what engine reaction?

Answer 8

The engine will default to idle RPM.

Question 9

What can be done to help cool hot engine oil, if still within limits?

Answer 9

Increase thrust. This will move colder fuel at a fast rate through the fuel oil cooler.

Question 10

The start valve solenoid is powered by what bus?

Answer 10

The DC Transfer Bus through the ENGINE START switch.

Question 11

Which engine instruments do not require electrical power?

Answer 11

N1
N2
EGT

Question 12

Which engine compressor section drives the accessory gearbox and how is this achieved?

Answer 12

N2, and this is done through a tower shaft.

Question 13

What accesories are mounted on the gearbox?

Answer 13

Pneumatic Starter
Engine driven fuel pump
Fuel control unit
Hydraulic pump
Tachometer generator
Oil pump
Constant Speed Drive (CSD)
AC Generator

Question 14

What is the recommended psi for a start and can an attempt with a lower value be made?

Answer 14

36 psi and yes you may attempt with a lower value.

Question 15

How many gallons of oil are in the engine oil tank and how many are usable.

Answer 15

5 total 4 of which are usable.

Question 16

Can an oil strainer be bypassed?

Answer 16

Yes. But you would see an oil strainer clogging light go on.

Question 17

How is oil cooled?

Answer 17

With airflow and by fuel absorbing heat in the fuel oil cooler unit.

Question 18

What psi does the low pressure engine driven fuel pump pressurize fuel to?

Answer 18

90 psi

Question 19

What psi does the high pressure engine driven fuel pump pressurize fuel to?

Answer 19

900 psi

Question 20

What is the path that fuel takes from the wings to the engines?

Answer 20

Low pressure fuel pump (90 psi)
Fuel heater
Fuel filter
High pressure pump (900 psi)
Fuel control unit
Fuel oil cooler
Combustion chamber

Question 21

Can the high pressure pump suction feed?

Answer 21

No, only the low pressure pump can.

Question 22

If the low pressure pump fails what engine operation is affected?

Answer 22

Fuel heating will not be operable.

Question 23

Can the engine run with the high pressure fuel pump broken?

Answer 23

No the engine will flameout due to fuel starvation.

Question 24

Where does the fuel filter get its air from?

Answer 24

The 13th stage bleed air. (Off its own manifold).

Question 25

Where does the Fuel Control Unit get its indications from?

Answer 25

N2 Inlet temperature (Tt2) Combustion chamber pressure (Ps4) Thrust lever settings

Question 26

Hos is the Fuel Control Unit driven?

Answer 26

By N2 off the engine accessory drive.

Question 27

What will happen if N2 sense is lost?

Answer 27

The engine will automatically drive to 95%. Throttle control will be lost.

Question 28

If the combustion chamber air pressure line ruptures what will happen to the engine?

Answer 28

It will be driven to idle RPM. Throttle control will be lost.

Question 29

What is the capacitance of the engine ignition system?

Answer 29

20 Joules

Question 30

When will the ignitors function?

Answer 30

When selected to either A or B and the fuel control levers ON.

Question 31

Are thrust reversers considered to be part of the landing criteria?

Answer 31

No

Question 32

What powers the RAT/EPR probe?

Answer 32

Right AC Bus

Question 33

Is that RAT/EPR probe heated?

Answer 33

Yes inflight only sensed groundshift.

Question 34

What does Automatic Reserve Thrust do and what does it look for? (MD80)

Answer 34

Compares engine N1 rotation against one another looking for a difference of 30%. Will increase thrust on the good engine by 700 lbs.

Question 35

What are the three things that will cause ART to fire?

Answer 35

30% difference in engine N1 Windshear Switching flight guidance systems

Question 36

What is the max thrust of JT8D-219 engines? (MD80)

Answer 36

21,000 lbs.

Question 37

What is the max start EGT for JT8D-219 engines? (MD80)

Answer 37

475 on the ground and 625 inflight.

Question 38

What is max continuous EGT for JT8D-219 engines? (MD80)

Answer 38

580

Question 39

What is max takeoff EGT for JT8D-219 engines? Is there a limit associated with this?

Answer 39

630 Reserve, 595 max. Has a limitation of 5 minutes.

Question 40

When does ART arm?

Answer 40

When both engines are above 64%

Question 41

What does Automatic Thrust Restoration do and when is it activated?

Answer 41

It will move both throttles up until one engine reaches its EPR limit. It is activated by vertical speed < 0 for 5 seconds or there is a .25 and 7% N1 drop on the same engine.

Question 43

When is Automatic Thrust Restoration armed?

Answer 43

Takeoff pitch selected in the flight directors Altitude is > 350 ft. Power is less than that for GA in both engines

Question 44

When does ART know when to engage?

Answer 44

By comparing N1 rotation and looking for differences that are greater than 30%.

Question 45

When does ART disarm?

Answer 45

When the slats are retracted,