In my mid-wing plane, straight (or not [8D]).
BTW, I did some searching ... and found [link=http://www.rcuniverse.com/forum/When_to_give_up_on_an_airframe%3F/m_2594052/tm.htm]this stuff on the subject (see the long post by George Hicks)[/link]. Worth reading for sure..
ORIGINAL: MTK
Take the stab away. Where will the wing go?
MattK
ORIGINAL: David Kyjovsky
Ok, I see now what you had in mind.
I have some doubts, though.
The model is normally trimmed so that this effect, very small IMHO, is fully compensated. A model that is trimmed to fly level hands off has no reason to pitch to belly simply because it was rolled to knife edge. On top of that, my last plane that pitches to belly is almost perfectly mid-wing.
The pitch to belly was always, among my models, most obvious in cap-ish designs (high mounted stab). But ONLY after the application of rudder. With neutral rudder (flying sort of ballistic knife edge for a while), the flight path was straight. After the rudder was applied, the belly pitch started. Must have something to do with the rudder deflection and its coupling to other axes, IMHO.
ORIGINAL: MTK
And you, me. That's like saying a wing generates zero drag. Or a wing generates no wake. Neither is true. Matters non at all whether a wing is symmetrical
Any low wing set-up will generate a natural pitch to belly. Center of drag is below the Center of Gravity.
MattK
ORIGINAL: David Kyjovsky
ORIGINAL: MTK
David, one of the main reasons a model pushes to the undercarriage in knife edge flight is the relatively low location of the center of pressure (CP), on the vertical stabilizer. The vertical downward force (moment) generated in such an arrangement is too small to counter enough of the natuiral down pitch moment any wing generates. The simple change of lowering the stab has a marginal affect on the knife edge, if that is all that is done.
...
You lost me here... what "natural down pitch moment" any wing generates? We talk about symmetrical airfoils here... no moment at all, as far as I know....