Engine

Question 1

What is the engine type ?

Answer 1

Pratt and Whitney PT6A-114A

Question 2

How much shaft horsepower is produced?

Answer 2

675SHP

Question 3

Max torque on takeoff?

Answer 3

1865ft-lb

Question 4

Max ITT on takeoff?

Answer 4

805deg (>765 limited to 5 minutes)

Question 5

Max Ng?

Answer 5

101.6% (102.6 transient)

Question 6

Max idle ITT?

Answer 6

685deg

Question 7

Normal oil pressure?

Answer 7

85-105psi

Question 8

Minimum oil pressure?

Answer 8

40psi

Question 9

Ng low and high idle?

Answer 9

52 and 65%

Question 10

Max transient torque?

Answer 10

2400ft-lb (20 seconds)

Question 11

Max transient ITT?

Answer 11

850deg (2 seconds)

Question 12

Max time in reverse?

Answer 12

1 minute

Question 13

Starting cycle?

Answer 13

Battery:
30 sec ON, 60 sec OFF, 30 sec ON, 60 sec OFF, 30 sec ON, 30 min off.

External power:
20 sec ON, 120 sec OFF, 20 sec ON, 120 sec OFF, 20 sec ON, 60 minutes OFF.

Question 14

Max ITT for start?

Answer 14

1090deg

Question 15

Max reverse torque?

Answer 15

1865ft-lb

Question 16

Normal oil temp operating range?

Answer 16

10-99deg. Below 10 ok for taxi. 10 required for takeoff.

Question 17

Oil capacity?

Answer 17

14Q (9.5 in tank)

Question 18

How does the fuel topping governor work?

Answer 18

At 106% selected RPM, the governor restricts fuel at FCU to prevent overspeeds in BETA range. It vents air pressure from the FCU which results in fuel flow reduction.

Question 19

How does the overspeed governor work?

Answer 19

At 104% prop RPM (1976) the flyweights open on the governor, pushing on the BETA valve, allowing oil out of the prop hub, increasing the pitch.

Question 20

How many stages of planetary gears in the RGB?

Answer 20

2:
First takes 33000RPM to 6600
Second takes 6600 to 1600-1900

Question 21

How many fuel nozzles in combustion chamber?

Answer 21

10 primary, 4 secondary

Question 22

How many ITT probes?

Answer 22

8

Question 23

Describe the propellor

Answer 23

3 bladed propeller, w/ constant-speed, full feathering, reversing, Beta mode control

Question 24

What are the Compressor Bleed Valves used for?

Answer 24

To vent excess axial stage compressed air overboard, because at low Ng rpm the 3-stage axial compressors produce more compressed air than the centrifugal stage can use, causing a compressor stall

Question 25

What would happen if compressor bleed valve stuck open?

Answer 25

ITT would increase, Torque would decrease, Ng rpm would remain constant

Question 26

What is the Compressor Bleed Valve used for?

Answer 26

To vent excess axial stage compressed air overboard, because at low Ng rpm the 3-stage axial compressor produces more compressed air than the centrifugal stage can use, causing a compressor stall

Question 27

Describe the oil system (kingair answer but should be similar)

Answer 27

1) Oil pressure pump supplies cooled pressurized oil through a filter
2) Then to the oil pressure & temperature transmitters, engine bearings, reduction & accessory gearcase, propeller control system, & engine torquemeter system
3) A scavenge pump returns oil from the reduction gearcase directly to the oil cooler & then back to the oil tank
4) Two scavenge pumps return the rest of the oil to the accessory gearcase
5) A screened scavenge pump inside the accessory gearcase returns the oil through the fuel heater & then back to the tank