Is this correct?

[41Sqn_Banks]

Originally Posted by robtek

But Banks, to reach and hold 3000 rpm the prop has to have fine pitch, not very efficient.

In the case of a constant speed propeller the RPM stays constant and the pitch depends on your airspeed. At low speed the pitch is fine, at high speed the pitch is coarse.

With a constant speed the car gear anaolgy fails, you have to think of a car with automatic gear where you choose between a economic and sports "mode".