"Vern" wrote in message
ble.rogers.com...
Is there a trade-off somewhere else in the perfomance envelope that makes
the larger prop less desireable on the land based versions?

This is just an assumption, but my educated guess would be that a larger
diameter propeller will create more static thrust, at the expense of cruise
seed. This is my experience flying a a 150hp Super Cub that went from a
standard 74" climb prop to an 84" seaplane prop (made it easier to hand prop
as well) The sea plane has more drag to overcome because of the floats in
the water versus wheels on the ground. Seaplanes have already sacrificed
speed for utility, what's a little more.

FWIW, some land planes DO have larger seaplane props, mainly aircraft that
need better shortfield performance. Bush planes, and banner tow aircraft
come to mind. Cruise speed is less of an issue, second to short field
performance, or extra thrust. The Super Cub lost about 5 knots off the top
end in cruise, but required 150 rpm less to pull the same banner, and had a
much shorter prop.