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Old March 25th 05, 04:13 PM
Stuart & Kathryn Fields
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Mark: Way back in the 60's I had a Benson gyro with a 90hp Mac engine with
a Dwyer wind speed gauge that used a small ball floating in a vertical tube
with the ram air entering the bottom and would push the ball up. The
readings stopped at 85mph but had another few inches of tube above the 85.
I can remember one high speed pass, and I'm not sure that I was really at
full throttle, that stuck the ball all the way at the top of the tube and I
had to take a pipe cleaner to push it back down. Looking at the scale we
estimated at least 105 -115. Maybe more with the ball being stuck. I now
think that I was seriously "Kicking the Bull Dog" and am lucky I didn't
discover a stalling blade or some other aerodynamic entertainment.

--
Stu Fields

"Mark" mark wrote in message ...
I have some basic questions about speeds of gyrocopters.

(Please forgive me if my questions are kind of basic. I'm currently

working
on my private pilot for airplanes, with long term goal of getting into
gyros. I have a few hours time in gyros, but not enough yet to know what
I'm talking about.)

Why is there such a wide range of max/cruise speeds for gyros? I notice a
Barnett BRC540 2 place cruises at 110 with a top speed of 138.
An RAF Cruises at 70 with a max of 100.
Most single places seem to cruise between 45 and 80.

Why aren't there more fast single place gyros?

Other than a bigger engine, why can a Barnett go 138 compared to RAF's

100?
What characteristics give it the stability to safely go faster? And why
wouldn't they design those characteristics into other gyros?

If I have a design of a stable gyro that cruises at 50, what would prevent
me from safely adding a bigger engine, re-doing my hang test, and flying

at
80 (for example).

If I build a gyro from a kit or plans, when I fly it how can I tell when

I'm
going faster than I safely should? (Other than reading designer's specs.)
Do all gyros have a characteristic "feel" when getting to the edge?