Posted for "Bill Kennedy" <bill_kennedy_3@hotmail.com>:
> I'm jealous -- my 320 is not so nearly well behaved. I usually get
an abrupt
>drop of the left wing, but recover easily. Wonder what I could
tweak to make
>it act more docile?
Being a former Engineering test pilot for a major manufacturer and
having done thousands (no exaggeration) of stalls to improve and to
determine stall characteristics. It will take a little time, but the
stalls can be improved without any loss of top speed. There two ways
to improve a stall like that one is to revise the angle of incidence of
the wing. This is a little hard on a 320/360. The other way to
improve the stall is to experiment with flow strips (stall strips).
First you determine your stall speed. The goal is to improve the stall
without significantly changing the stall speed. Usually the stall
handing qualities can be significantly improved by flow strips. So we
will try to improve the stall handing while noting the change in stall
speed.
I would start with 3 or 4 inch long strips,1/4" right angle aluminum works nicely as you can
tape this on to your wing leading edge slightly below the stagnation
point just inboard of the wing attach gap to the stub wing. Then fly
and check on the handling qualities and note the stall speed. If it
rolls to the right and there is no or little change in the stall speed
move the left strip up about 1/8" and refly noting the stall speed. The
idea in this change is to increase the stall speed of the left wing to
more closely match the right wing.
If after this procedure we get a good handling stall but if the
stall speed is up over 5 mph we need to move the flow strips down on
both wings about 1/16 to 1/8" This will reduce the speed that the
stall initiates. There are a multitude of variables but having
designed several flow strip installations to improve handling, this is
good view of the basics.
You need to write down each test configuration as later you might
find that a previous configuration is better. Be sure to carefully
mark the location of the strips as a little change can be very
significant. If you have questions don't hesitate to call or write.
Jack Webb
L 360, L IV
ATP, CFI Airplanes & Instruments, Multi,
& Sea
Many Type Ratings
Experienced Experimental Test Pilot both multi and single engine
Former Chief Engineering Test Pilot for a Major Manufacturer
AeroSpace Engineer BSAE
Ohio
419 399 5500
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