Powerplant

Question 1

What two identical units does the Pratt and Whitney of Canada PT6T-3B TwinPac consist of?
A. Free-shaft turbines driving the main transmission
B. Free-turbine turboshaft engines driving a combining gearbox
C. Gas producer sections driving a common power turbine
D. N1 sections driving identical N2 sections which drive the main transmission

Answer 1

B. Free-turbine turboshaft engines driving a combining gearbox

Question 2

Which unit is the primary drive responsibility of the gas producer (N1) section?
A. The main transmission
B. The combining gearbox 
C. The power turbine (N2)
D. The N1 accessory section

Answer 2

C. The power turbine (N2)

Question 3

The overall combining gearbox:
A. Reduces N2 rpm
B. Combines both engines' power output
C. Mounts and drives various N2 and C-box accessories
D. All the above

Answer 3

D. All the above

Reduces N2 rpm
Combines both engines’ power output
Mounts and drives various N2 and C-box accessories

Question 4

The combining gearbox is actually:
A. One section which reduces engine RPM
B. Divided into two sections of N2 gear reduction
C. Divided into three sections - two for gear reduction and one for combining
D. Divided into four sections - two for gear reduction, one for combining, and one for torque sensing, limit- ing, and sharing

Answer 4

C. Divided into three sections - two for gear reduction and one for combining

Question 5

N1 tachometer generator signals are used to indicate the percent of each engine’s N1 rpm on the N1 gage and to:
A. Actuate the low rpm light and audio warning systems
B. Actuate each engine’s ENGINE OUT warning light and particle separator system
C. Activate each engine’s N1 overspeed protection circuit
D. Activate torque limiting in the torque control unit

Answer 5

B. Actuate each engine’s ENGINE OUT warning light and particle separator system

Question 6

Interturbine temperature (ITT) indications are:
A. Self-generating by means of eight thermocouples
B. Provided by probes in front of the N 1 turbine wheel
C. Self-generating and direct-reading
D. Self-generating but require correction by the ITT trim compensator unit

Answer 6

D. Self-generating but require correction by the ITT trim compensator unit

Question 7

N2 tachometer generator signals:
A. Actuate the low rpm light and audio warning systems
B. Actuate each engine’s ENGINE OUT warning light and particle separator system
C. Provide cockpit N2 indications on the triple tachometer
D. Activate torque limiting in the torque control unit

Answer 7

C. Provide cockpit N2 indications on the triple tachometer

Question 8

Engine torque indication is a function of ______ which operates a sensor unit in the ______.
A. Engine oil pressure, N2 gear reduction section
B. Engine oil pressure, N1 turbine wheel area
C. Engine oil pressure, combining section of the C-box
D. C-box oil pressure, combining section of the C-box

Answer 8

A. Engine oil pressure, N2 gear reduction section

Question 9

Transmission torque is displayed on the dual torquemeter by:
A. A monopole sensor inside the main rotor mast
B. A separate torque sensor in the main transmission
C. A separate torque sensor on the combining gear in the C-box
D. Combining engine torque signals within the dual torquemeter

Answer 9

D. Combining engine torque signals within the dual torquemeter

Question 10

Optimum compressor efficiency and anti-stall operation during engine starting and N1 acceleration are provided by:
A. A compressor bleed band
B. A compressor air bleed valve 
C. Variable inlet guide vanes 
D. The compressor speed limiter

Answer 10

B. A compressor air bleed valve

Question 11

The engine oil-to-fuel heat exchanger regulates fuel heating by means of a thermostatic valve which is controlled by engine:
A. Oil temperature entering the heat exchanger
B. Oil temperature exiting the heat exchanger
C. Fuel temperature entering the heat exchanger
D. Fuel temperature exiting the heat exchanger

Answer 11

D. Fuel temperature exiting the heat exchanger

Question 12

The engine fuel filter system includes:
A. A bypass in the event of clogging
B. An automatic filter backwash and drain system
C. A FUEL FILTER caution light and a bypass
D. A FUEL BYPASS caution light

Answer 12

C. A FUEL FILTER caution light and a bypass

Question 13

The engine-driven fuel pump puts out high pressure fuel to operate the:
A. Fuel bypass system of the fuel filter
B. Fuel control unit, flow divider, and dump valve
C. Manual portion of the fuel control
D. Flow divider and dump valve

Answer 13

B. Fuel control unit, flow divider, and dump valve

Question 14

The fuel control unit on each PT6T-3B engine is:
A. Hydropneumatic with automatic or manual operation
B. Hydroelectric with automatic or manual operation
C. Pneumatic-electric with automatic or manual operation
D. Hydropneumatic, controlled only by the twist-grip throttle

Answer 14

A. Hydropneumatic with automatic or manual operation

Question 15

The flow divider and dump valve:
A. Drain fuel after engine shutdown
B. Separate fuel flow between the N1 and N2 burner sections
C. Separate fuel flow between the manual and automatic fuel control units and drain fuel from them after engine shutdown
D. Separate fuel flow between the primary and secondary fuel manifolds and nozzles and drain fuel from them after engine shutdown

Answer 15

D. Separate fuel flow between the primary and secondary fuel manifolds and nozzles and drain fuel from them after engine shutdown

Question 16

Engine ignition occurs:
A. Any time the starter switch is activated
B. Only if the fuel switch is in ON and the starter is activated
C. Continuously if the fuel switch is in ON
D. Only if the ignition and starter switches are in ON

Answer 16

B. Only if the fuel switch is in ON and the starter is activated

Question 17

Powerplant lubrication systems all function similarly since they all follow the same procedure of the oil.
A. Pressurizing, cooling, filtering, and using
B. Pressurizing, using, cooling, and filtering
C. Cooling, filtering, pressurizing, and using
D. Pressurizing, filtering, cooling, and using

Answer 17

A. Pressurizing, cooling, filtering, and using

Question 18

There are ______ engine oil pumps, _______.
A. Two, one for pressure and one for scavenge
B. Three, one for pressure and two for scavenge
C. Four, one for pressure and three for scavenge
D. Four, two for pressure and two for scavenge

Answer 18

C. Four, one for pressure and three for scavenge

Question 19

The primary indication of low engine oil pressure is the engine's:
A. OIL PRESSURE caution light
B. Oil pressure gage
C. OIL TEMP caution light
D. Oil temperature gage

Answer 19

B. Oil pressure gage

Question 20

A loss of engine oil pressure results in:
A. A loss of the C-box lubrication
B. A loss of the engine’s chip detector system
C. A loss of engine torque indication
D. Excessive heating of engine fuel

Answer 20

C. A loss of engine torque indication

Question 21

Excessive engine oil temperature should be treated in the same manner as:
A. A loss of the C-box lubrication
B. A loss of engine oil pressure
C. An engine chip
D. An engine fire

Answer 21

B. A loss of engine oil pressure

Question 22

The engine chip detector system includes:
A. One chip detector and an engine CHIP caution light
B. Two chip detectors and an engine CHIP caution light
C. Two chip detectors and two engine CHIP caution lights
D. Two chip detectors, one CHIP light, and two remote indicators

Answer 22

B. Two chip detectors and an engine CHIP caution light

Question 23

Overfilling the C-box oil system results in:
A. Excess oil being vented from the filler cap
B. Lower than normal C-box oil temperature
C. A popped red button on the remote indicator
D. Excess oil vented to the engine oil system

Answer 23

A. Excess oil being vented from the filler cap

Question 24

A remote indicator for the C-box oil system indicates:
A. Overfilling of the C-box oil system
B. Overpressure of the C-box oil cooler
C. The C-box oil filter is bypassed.
D. The C-box oil cooler is clogged.

Answer 24

C. The C-box oil filter is bypassed.

Question 25

Loss of C-box oil pressure results in:
A. Erroneous hourmeter readings
B. A popped red button on the remote indicator
C. Loss of transmission torque indication
D. Erroneous engine torque indication

Answer 25

A. Erroneous hourmeter readings

Question 26

The C-box oil system includes:
A. CHIP C BOX, C BOX OIL PRESS, and C BOX OIL TEMP warning lights
B. A CHIP C BOX caution light and C BOX OIL PRESS and C BOX OIL TEMP warning lights
C. CHIP C BOX, C BOX OIL PRESS, and C BOX OIL TEMP caution lights
D. C BOX OIL PRESS, C BOX OIL TEMP, and two CHIP C BOX warning lights

Answer 26

B. A CHIP C BOX caution light and C BOX OIL PRESS and C BOX OIL TEMP warning lights

Question 27

Excessive C-box oil temperature:
A. Is the same as excessive engine oil temperature
B. Requires an immediate landing
C. Is not a major concern and should be corrected prior to the next flight
D. Requires landing as soon as possible

Answer 27

D. Requires landing as soon as possible

Question 28

The type of FCU malfunction should be determined from the:
A. N1 and ITT gages
B. Dual torquemeter
C. Helicopter reaction
D. Triple tachometer

Answer 28

D. Triple tachometer

Question 29

The engine affected with an FCU malfunction can be determined from the:
A. N1 and ITT gages
B. Dual torquemeter
C. The degree of over- or under-speed
D. Triple tachometer

Answer 29

B. Dual torquemeter

Question 30

Low side FCU malfunctions require:
A. Throttle adjustment only
B. Throttle adjustment in manual mode
C. Engine shutdown and landing as soon as possible
D. No action other than engine shutdown

Answer 30

B. Throttle adjustment in manual mode

Question 31

High side FCU malfunctions:
A. May be controlled by reducing throttle from full open
B. May require entering manual FCU mode of operation
C. Require engine shutdown and land- ing as soon as possible
D. Either A or B above may be required

Answer 31

D. Either A or B above may be required

May be controlled by reducing throttle from full open
May require entering manual FCU mode of operation