Propeller System

Question 1

Max transient RPM?

Answer 1

For 20 seconds, 1870 RPM.

Question 2

Max reverse RPM?

Answer 2

1650 RPM.

Question 3

Ground prohibited range?

Answer 3

350 - 950 RPM

Question 4

ConstantSpeedUnit and Nf governing section are part of what?

Answer 4

Primary Governor.

Question 5

CSU is set to maintain what RPM?

Answer 5

1700 RPM.

Question 6

Nf is set to maintain what Np?

Answer 6

109% Np.

Question 7

Over-speed governor is set to maintain what RPM?

Answer 7

106% Np.

Question 8

When operating PCL in reverse, what governs prop speed?

Answer 8

Nf section of primary governor.

N(free turbine!)

Question 9

What should be ground idle Np?

Answer 9

1060 RPM.

Question 10

What is the primary governor?

Answer 10

Regulates supply of oil to the propeller hub which adjusts propeller pitch. (sensitive to changes in Np)

Question 11

What is the Nf section?

Answer 11

Operates in conjunction with the FCU to prevent prop-overspeed.

Essentially if the flyweights overspeed Py air bleeds and results in less fuel being metered.

Question 12

Over-speed governor:

Answer 12

It is like the primary governor; but it is maxed at 1802 RPM.

Question 13

What are the limits of each governor?

Answer 13

Primary = 1700 RPM
Nf governor: = 1853 RPM
Overspeed governor = 1802 RPM

Question 14

What will the propeller rotate on ground when set to idle?

Answer 14

1060 RPM.

Question 15

When would the LOW PROP P light come on in flight?

Answer 15

Only if the PCL is moved to the beta range.