Knife-edge causes strong belly tuck

Hello All,
I was hoping some folks out there would shed some light on why my 78" Extra
tucks during knife-edge flight. The airplane flies very well in all other
regimes of flight, but tucks strongly towards the belly during knife-edge
flight. I hold alot of UP elevator during knife-edge. I believe too much.
Is this normal?
TIA,
David
Reply to
Bellsouth News
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Try edging on the other side, if still tucks, you need more fin below center line perhaps.
Or perhps CG is too far aft.
Reply to
The Natural Philosopher
My Staudacher has the same vice. It does no matter the throttle setting or airplane attitude. I've been told (rumor alert) that the problem is the way the air spills over the cowl on these when it gets sideways. Changing engines helped a buddy with his (going from 4 to 2 stroke), and if you look at trimming charts it tells you to change the wing incidence. My elevator is dead flat in level flight, and doesn't take any noticeable down elevator to keep it level inverted. I moved the second battery pack 4 inches forward to cure it, and it had no effect.
So, solution was to live with it for me. I tried putting in elevator mix to cancel it, and left the mixing switch on for a crosswind landing. Thank God I had some excess speed when I put in some rudder and it ballooned on me. Haven't used the mix since.
Reply to
John Alt
Yup, no substitute for teaching the fingers to do the mixing!
Reply to
Paul McIntosh
you can do that????? WHAT A CONCEPT!!! ;-0
Reply to
Dennis Adamisin

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