On Tue, 01 May 2007 07:20:32 -0700, Dan_Thomas_nospam wrote:

Remember your training: check the POH. The setting you want
is the best range setting, which will give you the best distance for RPM
in a fixed-pitch airplane. If the airplane is really old and doesn't
have a range column in the cruise chart, you can find it by reducing the
power in cruise 100 RPM at a time, then allowing the airspeed to
stabilize and trimming for level flight. Keep track of the airspeed
decrease each time until you get a really large ASI drop, then go back
to the last setting.

You are right in the real world, but my purpose was to question whether
fixed pitch airplanes should be charged by tach time. From my
understanding, though, best range is defined in terms of fuel consumed
not tach time; i.e. given 38 gallons of usable fuel, the best range speed
is the one that will get you the farthest. My somewhat whimsical scenario
was to propose a method, given that the charge for the airplane is wet,
that would minimize the cost to the renter. I was trying to think of how
I could get from point a to point b with minimum time on the tach, not
with minimum fuel. I can think of alternatives such as doing the whole
distance at Vx, but I was trying to think how I could keep the rpms at a
minimum. In the end, the best method to minimize rental charges would be
to minimize average rpms x time in flight. Since I have absolutely no
intention to try my method (or a flight at Vx), I have no idea what would
really work best.