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Posted for J H Webb <airmale@bright.net>:
Marv,
Once again I was missed!! I don't know what is wrong. Following is
what I sent about 4 days ago.
[ pls use the lml@lancaironline.net address rather than
that old one -Rob@Logan.com ]
Hi Dan,
I am curious about your background with reference to your comment
about stalls. I find this hard to believe that there are so many OWT's
(Old Wife's Tales) still firmly believed by the aviation public. There
are virtually no airplanes left that exhibit the qualities that you
describe.
In about 33,800 hours of flying and years in experimental flight test I
have encountered only a few old airplanes that had other reasons to
ignore the stall characteristics and ahd bad low speed handling
qualities. As a graduate Aeronautical Engineer (with honors,
specializing in low speed aerodynamics) I find this discussion leaning
toward the absurd, much like the flat earth folks. I have done probably
over 10.000 experimental stalls and have flown many airplanes and am
always curious about their handling qualities.
That said, there are no requirements for satisfactory stall handling
qualities for experimental airplanes (custom built) as there are for
part 23 certificated aircraft, but the technology is well known and
seems to be almost universally applied by the larger experimental kit
suppliers. That technology is differential travel of the ailerons,
aerodynamic washout, physical washout, aileron gap control, aileron
sizing, and flow strips (stall strips).
If you have the time and inclination I could demonstrate for you the
advantages of using all three controls in coordinated flight vs using
different techniques for different conditions.
Your point is well stated as far as it goes but note one little thing
and that is the aileron does not go down as far as it goes up. Go
figure. Wonder why they did that? There is much more.
Now about wing drop, I have flown many 320's, 360's, L IV's, and L
IVP's. The airplanes in which have stalls that drop a wing I have
discovered have a mismatch in their angle of incident (the angle of the
wing chord with reference to the airplane) between the left and right
wing. My current Lancair IV is a good example as it had a bad wing drop
and it was easily fixed by adjusting the wings angle of incident. Now
it stalls straight ahead. Incidentally control at the stall is good. The
power on stall is not good enough to certificate but controllable.
Jack Webb
L 360, L IV
Ohio
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