PMU

Question 1

How does the PMU control the propeller RPM

Answer 1

Varying the propeller blade angle with oil pressure through the PIU

Question 2

How do the blades turn towards the coarse position

Answer 2

When oil presses against the piston is reduced

Question 3

Mechanical governor monitors Np to limit it to

Answer 3

106%

Question 4

The electrical governor monitors Np to

Answer 4

100%

Question 5

If the PMU is lost or deactivated, the mechanical fly-weight overspeed governor modulates oil pressure to what

Answer 5

100 +/-2%

Question 6

What happens when the PCL is placed in cutoff with the PMU in off and the PROP SYS circuit breaker pulled

Answer 6

The propeller will not rapidly feather and may not fully feather until after landing. You must put the circuit breaker back in

Question 7

How is the PCL connected to the FMU

Answer 7

Both electrically, and mechanically with a flexible cable

Question 8

What is the only thing on the AEDD that is processed by the PMU

Answer 8

Torque. N1, cockpit pressure altitude, cockpit differential, fuel flow, fuel quantity, and raw ITT are all not processed by the PMU

Question 9

What powers the PMU

Answer 9

The PMA. Permanent Magnetic Alternator. It supplies 32 VAC which the PMU converts to DC

Question 10

When does the PMU switch to the Battery bus

Answer 10

When propeller RPM drops below 40-50% or when the PMA fails

Question 11

When does the PMU abort a hot start

Answer 11

At 940 for 2 sec. 870 for 4 sec, or 840 for 19 sec. It will also abort if N1 acceleration rate to idle is less than 50% of normal