Dennis,
Great looking ships. What trim changes have you try to improve the cornering? Wings are really cool but have always seemed to have the corner issue. Since the corners definition doesn't have the 5ft radius and today there is more emphasis on shape than hard corner maybe the FA will be more competitive.
Maybe Bret/Howard/Ted could jump in and give some suggestions for modern trim technics to get the FA in the zone.
I am not sure where you get the first bit - the change in definition is effectively the same as changing the corner radius requirement to zero. 0 or 5, it's impossible either way. So, if anything, cornering is weighted more. That had nearly no effect, because that's what the really competitive guys were doing before, anyway.
I was studiously avoiding this thread, because despite all evidence to the contrary, I actually don't like being a buzzkill all the time. But since you asked....
Unfortunately, aside from the usual roll/yaw trim (and it has *very light* yaw damping), I don't think anything simple can fix the lack of cornering. It's more-or-less baked into the design. The crux of the issue is that, to generate a positive pitch rate, you have to camber the wing *the wrong way*. Basically, you are always trying to do outside loops in a Piper Cub (actually, much worse). The short coupling causes you to need to have a lot of elevator movement, and the more you move it, the more camber you have, and it's always working against you. I have flown a few of the originals (although not Bill's, nor the one you are building here) and it definitely showed the effect, more-or-less pointing the nose the wrong direction - pointing the nose up and translating "down" on small amounts of "up" elevator, then finally going the right direction as you panicked and deflected it more. I found it extremely unnerving to fly, because it was close to having effective control reversal on small corrections.
This one seems to show some evolution. Making the aspect ratio even lower increases the "tail moment", while minimizing the camber increase (since the same deflection of the narrower elevator has less negative effects on the camber, just because the chord is longer. I am sure that the wider tips are there to permit you to put the leadouts in the tip, rather than about 3/4 out the leading edge, which is where it really needed to be on the original 35-sized version.
This is particularly true if you just hinge the elevator to the TE of the wing. Bill, naturally, understood the problem with it as well or better than anyone. Later versions of the original Fierce Arrow, and Bob Baron's gigantic 45FSR version, had an offset hinge line with the effect of causing a slot to open when the elevator deflected, with the net effect of turning it into a very very short-coupled combat wing. The tail moment is about 3/4"! That improved it, but it's never going to be a world-beater.
It's a neat idea, but the best assessment I ever heard was at some Northwest Regionals, after Ted test-flew someone's FA (original) - "Thanks for letting me fly that, because it saved me the 3 months I was going to take to build one".
Enjoy it for what it is, learn something pretty important about aircraft design, but don't expect to blow anyone out of the water in a big contest.
Brett
Topic: FIERCE ARROW 875 (Read 3555 times)