Powerplant

Question 1

Max Takeoff Power SHP

Answer 1

5071 SHP

Question 2

Describe Nl

Answer 2

Low pressure axial compressure

Question 3

Describe Nh

Answer 3

High pressure centrifugal compressor

Question 4

What is the engine accessory gear box driven by?

Answer 4

high pressure (Nh) compressor rotor

Question 5

What components are on the engine accessory gear box?

Answer 5

Fuel Metering Unit (FMU) (Fuel Pumps)
Oil Pump
DC Starter-Generator
Permanent Magnet Alternator (PMA)

Question 6

How much extra power does the FADEC deliver when the power levers are over-traveled past the rating detent?

Answer 6

25%

Question 7

What components are mounted on the propeller reduction gear box?

Answer 7

Hydraulic Pump (main engine-driven pump)
AC Generator
Pitch Control Unit (PCU)
Auxiliary Feathering Pump
Propeller Overspeed Governor

Question 8

Maximum reverse thrust SHP

Answer 8

1500 SHP

Question 9

Describe the FMU.

Answer 9

The electro-mechanical Fuel Metering Unit is driven by the engine accessory gearbox and controls fuel flow to the engine based on signals from the FADEC.

Question 10

How many fuel pumps are in the FMU?

Answer 10

two integral engine driven fuel pumps; a low pressure pump and a high pressure pump

Question 11

What are the functions of the FADEC?

Answer 11

controls engine fuel flow
controls various engine bleed valves to prevent compressor surges and stalls
prevents engine overspeed
controls automatic start and shutdown
supplies voltage to the Propeller Electronic Control (PEC)
detects and indicates powerplant faults

Question 12

Electrical power source for the FADEC

Answer 12

Permanent Magnet Alternator (PMA) driven by the accessory gearbox when Nh is above 20%; essential DC bus initially

Question 13

FADEC responds to a critical fault with…

Answer 13

either a power stabilization to flight idle or engine shutdown.

Question 14

An uptrim condition is indicated in the cockpit by:

Answer 14

“UPTRIM” message on ED
change in power rating from NTOP to MTOP on ED
change in torque bug position from NTOP to MTOP

Question 15

A power uptrim will occur when either of the following conditions exist:

Answer 15

torque on the failed engine falls below 25%

power turbine speed (NPT) falls below 80%

Question 16

Describe the Nh overspeed protection.

Answer 16

powerplant has an independent overspeed protection circuitry (dual channel) built into the FADEC which has the capability to cut off fuel flow to the engine.

Question 17

Propeller system components

Answer 17

Propeller Electronic Control (PEC)
Pitch Control Unit (PCU)
Propeller Overspeed Governor Unit (POG)
Auxiliary Feathering Pump
Automatic Propeller Synchrophase System

Question 18

Describe the PEC.

Answer 18

The Propeller Electronic Control is a dual channel microprocessor based controller which uses inputs from the airplane, propeller control system sensors, and the engine control system to control propeller pitch and speed.

Question 19

Describe the functions of the PEC.

Answer 19

Autofeather
Automatic Underspeed Propeller Control
initiates power UPTRIM command to the FADEC

Question 20

Describe the PCU.

Answer 20

The Pitch Control Unit is a hydromechanical device that uses oil PSI to control the pitch of the propellor

Question 21

Describe the POG.

Answer 21

The Propeller Overspeed Governor unit is an independent mechanical system used to limit the propeller speed in case of a propeller overspeed malfunction;

Question 22

Describe the Auxiliary Feathering Pump.

Answer 22

The Auxiliary Feathering Pump consists of a 28 volt DC electrical motor driving an external gear pump providing a secondary source of oil pressure for feather the propeller. The pump is automatically activated when autofeather occurs and is manually activated when alternate feather is selected.

Question 23

When does the autofeather system arm?

Answer 23

autofeather system select ON

torque of both engines exceeds 50% and both power levers are advanced beyond a 60 degree angle.

Question 24

When does the autofeather system trigger?

Answer 24

torque of the failed engine falls below 25% for at least three seconds

Question 25

How long does the Auxiliary Feathering Pump activate after an autofeather?

Answer 25

approximately 30 seconds

Question 26

Explain how the POG works.

Answer 26

incorporates hydraulic and electronic section to reduce high pressure oil supply when prop speed exceeds 1071 rpm and/or uses FADEC FMU to reduce amount of fuel to the engine when prop speed reaches 1122 rpm

Question 27

Describe the engine ignition system.

Answer 27

consists of one dual channel exciter unit and two igniter plugs in the combustion chamber; controlled by FADEC

Question 28

Name and describe the start malfuntions.

Answer 28

Hot start - ITT exceeds 920C
No light off - engine does not light within 16 seconds of fuel intro
Hung start - Nh does not reach 50% within 70 seconds
START light remains illuminated - No starter cutout
SELECT light remains illuminated - Starter Failure

Question 29

When does the START SELECT switch automatically center itself during at start?

Answer 29

Nh reaches approximately 50%

Question 30

How is engine oil cooled?

Answer 30

Air to Oil heat exchanger (cooler door located on the underside of the engine nacelle)

Question 31

1 or #2 ENGINE OIL PRESS warning light

Answer 31

engine oil pressure below 44 psi - EMER shutdown

Question 32

1 or #2 ENGINE FADEC FAIL warning light

Answer 32

FADEC has malfunctioned - EMER shutdown

Question 33

1 or #2 ENG FUEL PRESS caution light

Answer 33

pressure at engine driven fuel pump inlet is low, ejector pump failure or loss of motive flow to the ejector pump

Question 34

1 or #2 ENG FADEC caution light

Answer 34

FADEC sensed a condition that requires caution when applying control inputs

Question 35

1 or #2 PEC caution light

Answer 35

PEC senses a beta mode malfunction

Question 36

Normal Takeoff Shaft Horsepower

Answer 36

4,580 SHP