GK (random)

Question 1

What is the flat rated shaft horsepower output of the PT6A-68 engine?

Answer 1

1100 SHP

Question 2

What are the two sections of the T-6’s engine?

Answer 2

• Gas generation section
• Power turbine section

Question 3

What components make up the gas generator section of the engine? (aft half)

Answer 3

• 4 Stage Axial Flow Compressor
• Single-Stage Centrifugal Flow Compressor
• Combustion Chamber
• Single-Stage Compressor Turbine

Question 4

What components make up the Power Turbine section?

Answer 4

• 2 Stage Axial Flow Power Turbine
• Reduction Gearbox

Question 5

Briefly describe the flow of air into and through the engine?

Answer 5

Air enters the intake cowling beneath the prop and flows first through an inertial separator. It then turns 180 deg and passes through a 4 stage axial compressor and a single stage centrifugal compressor. From there, it enters the combustion chamber, is mixed with fuel and is lit. The expanding air first passes over the compressor turbine, making the engine self- sustaining, and then passes over the two power turbines before passing through the exhaust ports and diverted rearward by the exhaust stacks.

Question 6

What is the capacity of the oil system?

Answer 6

18.5 quarts

Question 7

What components does the oil system supply filtered oil to?

Answer 7

• Engine Bearings
• Reduction Gears
• Accessory Drives
• Propeller

Question 8

When must oil be checked and where to get an accurate reading?

Answer 8

Within 30 minutes of engine shutdown and using the dipstick, not the sight gauge.

Question 9

When does the Amber OIL PX illuminate?

Answer 9

• IDLE - 15-40psi - no time delay
• >IDLE - 40-90psi - 10s

Question 10

When does the Red OIL PX illuminate

Answer 10

IDLE - <15psi - no time delay

>IDLE - <40psi - no time delay

Question 11

When does the Amber and Red OIL PX illuminate?

Answer 11

IDLE - 15-40psi - 5s

Question 12

The engine oil pressure indicator may display oil pressures up to __ psi with the engine shut down due to the design of the oil pressure transmitter.

Answer 12

4

Question 13

Caution: For most accurate results, check oil level how many long after shutdown?

Answer 13

15-20minutes

Question 14

Caution: What is the only acceptable method for getting a correct indication of oil level?

Answer 14

Dipstick

Question 15

Note: T/F Due to the sensitivity of the SCU, a single, momentary illumination of the amber OIL PX annunciator while maneuvering indicates a system malfunction.

Answer 15

False

Question 16

The Reduction Gear Box reduces shaft output speed from ______ RPM to a propeller operating speed of ______ RPM.

Answer 16

Over 30,000 - 2,000

Question 17

What drives the RGB?

Answer 17

Hot Gases impinging on the 2-Stage Power Turbine

Question 18

What does a red CHIP annunciator indicate?

Answer 18

Contaminated oil

Question 19

T or F: the RGB is mechanically connected to the gas generator section of the engine?

Answer 19

False - No Mechanical Connection to the Gas Generator Section

Question 20

What accessories are mounted on the reduction gearbox?

Answer 20

• Prop interface unit (PIU)
• Torque probe
• Permanent magnetic alternator (PMA) (on top)
• Air conditioning compressor (belt driven) (on right side)

Question 21

A chip detector is mounted in the RGB to detect ferrous material in the ___.

Answer 21

oil

Question 22

The propeller system is designed to maintain a constant speed of _____ during most flight conditions?

Answer 22

2000 RPM (100% Np)

Question 23

What is the unit on the primary engine data display that indicates prop speed?

Answer 23

Np

Question 24

At 100% indicated torque, the engine is producing approx _____ foot pounds of torque at the prop shaft?

Answer 24

2,900 ft-lbs

Question 25

What are the three basic conditions of propeller pitch?

Answer 25

* Feathered * Low pitch (flat or fine) * High pitch (coarse)

Question 26

Approximately what is the blade angle of the propeller at low pitch?

Answer 26

15°

Question 27

Normally, propeller governing is automatically set by the ____ and \_\_\_\_.

Answer 27

PMU and PIU

Question 28

What happens to the prop if there is an engine failure with the PCL out of the CUT-OFF position?

Answer 28

The prop will slowly begin to feather due to loss of oil pressure but MAY NOT fully feather.

Question 29

Power for the feather dump solenoid valve is provided through which circuit breaker?

Answer 29

PROP SYS

Question 30

With the PMU functioning, the _______________ will modulate oil pressure to the prop pitch change piston to limit Np to 106%, while electronic governor will keep Np at 100%.

Answer 30

mechanical overspeed governor

Question 31

If PMU is not functioning, the ______________ will modulate oil pressure to maintain Np at or below 100+/-2 %.

Answer 31

flyweight overspeed governor (checked in hammerhead)

Question 32

What will happen if the PROP SYS CB is pulled, the PMU is off, and the PCL is placed in CUT-OFF?

Answer 32

The prop will not rapidly feather and may not fully feather until after landing

Question 33

During an auto start or normal operations with the ignition set to NORM, the ____ will energize and de-energize the igniters as required.

Answer 33

PMU

Question 34

Power for the START control is provided through a circuit breaker placarded START, located on the ________ bus circuit breaker panel in the front cockpit.

Answer 34

battery

Question 35

During an auto start or normal operation with the IGNITION switch set to \_\_\_\_\_\_\_\_\_, the PMU will energize and de-energize the igniters as required.

Answer 35

NORM

Question 36

Power for the IGNITION system is provided through a circuit breaker, placarded IGN, located on the _______ bus circuit breaker panel in the front cockpit.

Answer 36

Battery

Question 37

**T/F** If the IGN SEL message remains continuously illuminated, notify maintenance personnel after the mission.

Answer 37

True

Question 38

The _____ PCL is connected to the Fuel Management Unit (FMU) both electrically and mechanically with a flexible cable.

Answer 38

Front

Question 39

**T/F** When the PCL is moved forward to idle during engine start, two roller bearings lock in place on the front side of a rocker cam detent to secure a gate.

Answer 39

Ture (This is what makes the two audible clicks when pushing the PCL up @ 60%)

Question 40

What is the primary source of power for the PMU?

Answer 40

PMA

Question 41

What sort of power does the PMA provide?

Answer 41

32 VAC, and the PMU converts that to DC power

Question 42

When does the PMU automatically switch to 28 VDC from the battery bus?

Answer 42

* When the prop PRM drops below 40-50% Np * When the PMA fails

Question 43

The aircraft weight on wheels switch on the main gear struts controls what for the PMU?

Answer 43

PMU In Flight and Ground Mode

Question 44

In ground mode, what is idle? Flight mode?

Answer 44

* 60% N1 * 67% N1

Question 45

Above ______ feet MSL the PMU raises N1 to maintain Np above 80% to avoid stress on the propeller during spins.

Answer 45

10,000' MSL

Question 46

Relation of PCL position to power setting is _______ with the PMU operating.

Answer 46

Linear

Question 47

In what situations will the PMU automatically abort the start?

Answer 47

* light off has not occurred within 10 seconds of selecting AUTO/RESET * ITT exceeds 940 deg C for 2 seconds, 870 for 4 sec, or 840 for 19 seconds * N1 acceleration rate to idle is 50% less than normal

Question 48

The PMU will go offline when the IOAT exceeds \_\_\_\_\_?

Answer 48

121°C

Question 49

When does hydroplanning occur (nose wheel vs. main wheel)?

Answer 49

Nose wheel: 85 kts Main wheel: 115 kts

Question 50

Tire pressure (nose & main)

Answer 50

Nose: 120 +/- 5 psi Main: 185 +/- 5 psi

Question 51

Until below what quantity does the fuel probe measure?

Answer 51

Outer probe fail: 445 ± 50 lbs Middle probe fail: 308 ± 50 lbs

Question 52

Tire wear (nose gear)

Answer 52

No visible cords

Question 53

Main tire wear (Michelin)

Answer 53

Always (and local) sortie: **_no red cords_** O+B: **_maximum of 3 cords_** X-Country sorties: **_maximum of 2 cords_**

Question 54

Main tire wear (Goodyear)

Answer 54

Always: **_no red cords_** Local sorties: **_one white cord_** O+B or X-Country: **_no cord visible_**