Powerplant

Question 1

What is the powerplant type?

Answer 1

Pratt and Whitney PT6A-67B

Question 2

How is the PT6 rated?

Answer 2

1600 SHP, flat rated to 1200 SHP at 1700 RPMs.

Question 3

What does the inertial separator do?

Answer 3

It prevents FOD or ice from entering the engine when in the open position. Must be open when operating on the ground or when in visible moisture and temps below 10C.

Question 4

How many stages are in the compressor section?

Answer 4

4 stage axial, 1 stage centrifugal.

Question 5

What does the compressor relief valve do?

Answer 5

It automatically opens using P2.5 air vented into the intake through piccolo holes to prevent compressor stall at low power settings.

Question 6

How many nozzles are in the combustion section?

Answer 6

14 duplex type nozzles. Primary and secondary valves are in the same nozzle.

Question 7

When do the secondary valves kick in?

Answer 7

Above 45% NG.

Question 8

How many spark plugs are there?

Answer 8

2 spark plugs powered by a single igniter.

Question 9

How does auto-ignition work?

Answer 9

Prevents flame out at low power settings. Engages when ITT drops below 500C and NG is above 10%.

Question 10

Describe the turbine section?

Answer 10

Single stage compressor turbine and two stage power turbine.

Question 11

Where does NG come from?

Answer 11

NG is measured from the single compressor turbine.

Question 12

What speed is 100% NG?

Answer 12

100% NG equals 37,469.

Question 13

What is the speed of the power turbines (NF)?

Answer 13

Power turbines or NF at 100% NG are 29,894.

Question 14

How is the power turbine speed reduced to the propeller speed?

Answer 14

The power turbine speed is reduced to the propeller speed (NP) of 1700 RPM in the Reduction Gear Box.

Question 15

What can damage propeller reversing linkage?

Answer 15

Moving the PCL into BETA/Reverse range while the propeller is feathered.

Question 16

What oil does Boutique use?

Answer 16

BP2380. Mixing of brands prohibited.

Question 17

How does the fire detection tube work?

Answer 17

Its a tube containing helium with a hydrogen core.

The tube heats up and hydrogen gas leaves the core raising the pressure in the tube which activates the pressure sensor.

Question 18

Describe the powerplant?

Answer 18

Reverse flow, free turbine, 1600 SHP flat rated to 1200 SHP at 1700 RPM. Mounted 2 degrees right and 2 degrees down.

Question 19

How is ITT measured?

Answer 19

Measured between the Compressor Turbine and First Power Turbine with 8 individual sensors that average out.

Question 20

What effect of performance or gauges will you see when the Inertial Seperator is OPEN?

Answer 20

Decrease in torque.

Increase in ITT.

Question 21

What percent of air entering the engine is ignited and burned vs. used for cooling?

Answer 21

20% ignited and burned.

80% is used for cooling.

Question 22

How long will the starter run when the sequence is initialized?

Answer 22

60 seconds or until NG reaches 50%

Question 23

At what point during the start sequence do you move the CL to ground idle?

Answer 23

Once NG is stabilized above 13%.

Question 24

How do you interrupt the start sequence?

Answer 24

Pressing STARTER INTERRUPT.

Question 25

What temp do you want to see before introducing fuel?

Answer 25

ITT TRENDING (CA) below 170.

Question 26

How is NG governing accomplished?

Answer 26

In the 3D cam (component of FCU).

Question 27

What does the torque limiter do?

Answer 27

Operates in conjunction with the FCU to prevent exceeding 44.3 PSI.
Measures torque meter oil against a limit spring.

Question 28

Where is the torque measured?

Answer 28

In the RGB.

Question 29

What is the proper time to check the oil?

Answer 29

Between 10 and 20 minutes after shutdown or 12 hours after shutdown.