"DanH" wrote in message
...
AJW wrote:

[snip]
For what it's worth, at 150 kts and 2500 RPM means the airplane advances
about
6 feet per prop rev. A two bladed prop means each balde is in air 3 feet
ahead
of the prior blade.

That's the same number I came up with, but that assumes there's a
one-to-one ratio between engine RPM and prop RPM. Is that true of all
single engine piston aircraft? I'm obviously not an AC mechanic, but I
thought I could see a reduction gear in the cowl.

DanH

In addition, the term "slippage" comes into play. That's the difference
between the theoretical distance the prop should advance with each
revolution and the actual.

And besides a reduction gear creating a difference between engine and prop
RPM, a constant speed prop gives control of the prop speed to the pilot or
the prop governor mechanism.

--
Scott