>I don't think mine are too big, or too small, really. There's a serious >pitch change when I deploy them even though though only operate over a 30 >degree range at this point (mainly due to real estate considerations under >my seat). >Mark Langford ++++++++++++++++++++++++++++++++++++++++++++++++++++++++=
Mark, I'll go out on a limb here and let the experts correct me if I'm wrong. I think your pitch change comes from the center of lift moving on the wing as the flaps are deployed. I would guess the "serious pitch change" you mentioned speaks to their effectiveness. If your rate of decent increases while holding the same airspeed and power setting then you're adding drag as well as lift. You might try some flight testing to see if a small flap deflection shortens your takeoff roll and helps your climb at best angle. Have you considered rigging the flaps for negative deflection at cruise to pick up a few mph? I get a nose down pitch movement on my KR when I lower the speed brake but for other reasons entirely. ( I'm guessing) that there is a pressure build up in front of the brake when lowered that is applied to the bottom side of the fuselage and it being behind the center of lift would cause a nose down pitch. That and (again, I'm guessing) that the downward deflection of the air at the brake would contribute to the nose down pitch also. And (I'm guessing again) the drag forces being applied below and behind the C.G and C.L would cause the drag forces to align with the C.G., similar to the feathers on an arrow. Or, maybe I've just spent too much time at altitude without oxygen !! I suppose if we really wanted to know we could hook up several altimeters and place the tubes at several different points and measure the pressure differences. But hey, I have wheel pants to install, trim to apply, flying to do, :-) .............................. Larry Flesner
