Swept back wing tips and a fairly high wing loading kind of help keep models from bouncing around too much.
My 68 ounce intrepid could do consecutive maneuvers in dead calm and the worst that would happen is a gentle rocking of the wings.  That's pretty good in my book when dealing with vortexes that can smash a lighter airplane into the ground in a fraction of a second.  Don't ask me how I know a vortex can smash a model into the ground that fast.     If I had a video of what happened to my Magnum at John Simpson's house while I was practicing two weeks before the 2004 Nats you would know for sure.  However, I don't! 

Jim Pollock, possessor of splintered Magnum parts when it buried itself to the wing root in outside squares.......Ugh!

I think the tapered, high-aspect-ratio wings are a significant advantage - more so than good tip shape choices.

  FAR more significant.

    Brett

Guys,
In our area we have to conditions that dominate - 12+ wind or dead calm. In looking at the ships that seem to handle the conditions with the least problems it seems that particularly in the calm the ships with the lesser depth to the fuse have the edge. The extreme is with the profile fuse. My ship has a very depth fuse, lots of side area. In the calm it seems to generate lots of turbulence and keeps you on your toes. A fellow flyer has a ship that has about half the depth of mine and in the calm he seems to be able to just stand there and do the consecutive maneuvers with very little need to move. Both ships have flaps and are about the same wing area and load. Anyone else notice this with full fuse ships?

Best,          Dennis

I can think of 4 design points to achieve better wind handling:
1) Less fuse side. I am not big on this approach as it also eliminates the benefits of having a deep fuse.
2) Design for CG to be close to CL. The smaller the distance, the less of an "arm" wind has to push with. It also helps with windup in the rounds.
3) Increase fuse area in front of CG. Most designs had a lot of area in behind the CG and not enough in front of it. If you design a fuse so that has equal areas around the CG.
4) Do not build rudder offset. On the downwind side, rudder with an offset presents a large area at exteme arm lenght for the wind to push on and cause it to turn into the circle. On the upwind side, it forces it to point outwards, taking away engine thrust from moving the model forward.

I bet that your fellow flier has more rearward CG on his model.

3) Increase fuse area in front of CG. Most designs had a lot of area in behind the CG and not enough in front of it. If you design a fuse so that has equal areas around the CG.
4) Do not build rudder offset. On the downwind side, rudder with an offset presents a large area at exteme arm lenght for the wind to push on and cause it to turn into the circle. On the upwind side, it forces it to point outwards, taking away engine thrust from moving the model forward.

3) This is what one would think (and what Isaac Newton and Brad Walker figured), but the response of an airplane in sideslip isn't the superposition of the effects of wind blowing head-on and wind blowing sideways. 

4) This is the effect of a vertical stabilizer, regardless of rudder offset.  It's not all bad.  Rudder offset causes a yawing moment proportional to airspeed squared, pretty much independent of wind unless you put the vertical stabilizer at a really high or low angle of attack.

For calm conditions...

I think the tapered, high-aspect-ratio wings are a significant advantage - more so than good tip shape choices. I liked my A/R-6.3 wing a lot. These can cause problems in gusts though.

SK

And can be a significant disadvantage if the wind comes up, both in turbulance and heavy wind up . I love flying high AR wings in none or very light winds, but that doesn't happen much in the contest I go to.

The high AR wings also benefit from good tip shapes

The best I have found for all conditions is around a 5.5 to one AR and clean tips, also I think somewhere around a 19% airfoil works well with typical stuntships the way we tend to load them

Regards
Randy

The high aspect planes I built (from 6.8 to an interesting experiment at 9.5 to 1) flew great in calm conditions or even very windy conditions that had clean air and not much turbulence. It was the turbulence that killed them. I used both blunt, thick airfoils and in the last couple I did, 19% (root) airfoils with severe vertical taper to around 10% at the root. The last couple flew pretty well in moderate turbulence. But at the sites we tend to fly at around here (surround by trees and buildings), even moderate turbulence is a lot.

Randy,

Yep, that's pretty much it. It wasn't worth the drawbacks to get the advantages.

We used to fly at a site that was flat as a tabletop with no obstructions around for at least 3/4 of a mile. Nothing,, not even a chain link fence. Had a paved area that was about 5 acres with nothing around. The wind came up and while it wasn't turbulence free, it was probably as close as you were likely to get. Even when pretty windy.

I miss that place.

Yup,

You can fly in wind of 15-20 MPH on circle 2 and there is nearly no turbulence whatsoever.  Not so on circle 4 however!  Paul can elaborate about how he chased my plane around there in order to get the engine stopped after an unscheduled meeting with the asphalt and my landing gear in a high load situation.

Jim Pollock,  Sheesh, gotta get that plane back in the air someday with it's new PA .61!

Here's a site that's smack in the middle of salt water marshes next to the ocean. The ocean winds are strong with some days where we can't even leave the models on the ground for the wind flips them over.
The air is clean until everyone starts showing up with a van and parking on the upwind side  . Then it get's fun!!!!

http://www.flashearth.com/?lat=42.433597&lon=-70.997463&z=19.7&r=0&src=msl            


Has anyone experimented with small flaps? I used to fly Cardinals with huge flaps and they didn't like turbulence at all. Dave Cook's Lightning(high AR wing) derivatives have fairly small flaps and don't care as much about the turbulence. Is this just a freak coincidence or is there some truth to this?