Propellor Sytems

Question 1

What is the effect of adjusting propellor pitch?

Answer 1

Allows the propellor to absorb more power from the engine.

Question 2

Which component alters the blade pitch and what powers it?

Answer 2

Pitch control unit (PCU) located in the prop hub. Powered by springs and engine oil pressure.

Question 3

What is the pitch control unit controlled by and what does it comprise?

Answer 3

The constant speed unit (CSU). Comprises the hydraulic governor which uses engine oil pressure.

Question 4

What sets the regulating speed for the governor?

Answer 4

The RPM/Prop lever in the cockpit.

Question 5

What two extremes can the prop lever be set between?

(Bonus question: When might each be used?)

Answer 5

Fully coarse (low pitch) and fully fine propellor (high pitch).

Full fine used for takeoff and full power climb. Full coarse could be used in the event of engine failure (feathered prop)

Question 6

What is the purpose of the centrifugal latch and what effect does it have on engine startup?

Answer 6

Prevents the propellor from going fully coarse on engine shutdown. These eases the engine load on startup.

Question 7

How is cabin noise reduced on multi-engine designs?

Answer 7

Synchronising or syncrophasing