Propeller and Oil System

Question 1

What are the 2 electric servos associated with the DEEC?

Answer 1

Throttle and stop/feather

Question 2

What does the DEEC throttle servo do?

Answer 2

Provides backup engine control in case of DEEC failure and controls propeller pitch at settings below flight idle.

Question 3

What does the DEEC stop/feather servo do?

Answer 3

set by RCM in response to pilot’s condition lever position

Question 4

Prop shaft RPM

Answer 4

1591 max continuous

Question 5

Prop diameter?

Answer 5

110 inches

Question 6

Prop pitch range?

Answer 6

-10 to 90

Question 7

In ground mode, what meters oil to the prop?

Answer 7

pitch control unit

Question 8

What controls engine RPM in response to how the pilot sets the throttle and speed lever?

Answer 8

propeller governor

Question 9

What are the two modes of the propeller control system?

Answer 9

Flight and ground mode

Question 10

How does flight mode work for the prop governor?

Answer 10

In flight mode, the throttle establishes fuel flow and the propeller governor automatically adjusts oil pressure to maintain a constant RPM by changing blade angle.

Question 11

How does ground mode work for the prop governor?

Answer 11

In ground mode, throttle position establishes
the blade angle, and the fuel control automatically adjusts fuel flow to maintain a constant RPM, which allows for finer thrust control during taxi.

Question 12

When is the prop in ground mode?

Answer 12

Between flight idle and full reverse

Question 13

When is the prop in flight mode?

Answer 13

Between flight idle and max power

Question 14

What is the beta light an indication of?

Answer 14

The engine is operating in ground mode meaning the throttle lever position controls prop pitch angle (Ground mode)

Question 15

The beta light may not illuminate if engine RPM is less

than 85%. Why?

Answer 15

At lower RPM the prop control oil pump out put is lower (than max of 450lbs px)

Question 16

What does the prop unfeather pump do?

Answer 16

electrical oil pump that pushes prop onto start locks

Question 17

At max capacity the Oil reservoir holds ____ quarts of oil? (block 5 _____)

Answer 17

9qts (block 1) 14qts (block 5)

Question 18

What psi differential is the oil reservoir vent regulator valve?

Answer 18

7pisd

Question 19

What is the psid of the oil reservoir pressure relief valve?

Answer 19

12psid

Question 20

Where is the chip detector located?

Answer 20

the oil reservoir

Question 21

The chip detected warning light will stay on until?

Answer 21

the chip detector is cleaned

Question 22

What does the fuel/oil heat exchanger do?

Answer 22

on the ground warm fuel pumped through a rigid coil in the reservoir heats engine oil. airborne, the warm oil is used to preheat the fuel and prevent thickening

Question 23

How many microns is the oil filter?

Answer 23

25

Question 24

If the oil filter clogs, so that pressure drop across the filter exceeds ___-___ psi, the normally
closed bypass valve will open to allow oil to go around the filter.

Answer 24

55-70 psi

Question 25

The TCV controls the flow of oil to the air/oil heat exchanger, allowing cool oil to bypass the air/oil
heat exchanger. It starts to open at __°C and is fully
open at __ °C.

Answer 25

85 °C (185 °F) and is fully open at 91 °C (195 °F).

Question 26

At what point during engine start does the oil vent valve close?

Answer 26

60% rpm (looks like an increase in oil px)

Question 27

The TPE-331 engine may burn up to __ qts of oil per ___ hrs of operation during normal flight operations.

Answer 27

1 qt / 12.5hrs

Question 28

The pilot must set the throttle to reverse during engine shutdown prior to dropping below ___% RPM for the pitch latches engage

Answer 28

40%

Question 29

If the BETA light is on continuously in flight, it may indicate (5 things)

Answer 29

rigging problem, low fuel flow, failed beta switch, insufficient airspeed or improperly calibrated throttle