ORIGINAL: BFoote
Exactly. Depends on the airfoil in question.
Got the books.
Can download said profiles for free to anyone who is interested. Do a search for Selig and Illinois Urbana champagne university and you will find his site with the ability to download the data files. In zip form by the way.
As to a5BY why on stunt you can get away with it. Even in a stall you are generating lift. It does not matter in a control line if one wing tip stalls as centrifugal force from the line holds the model in the air and therefore you can tip stall all you want. Likewise said models are so overpowered it does not matter if you are flying in a 100% stall all the time. In fact for stunt you want the tip to stall quite often as it will make a snappier performer.
Actually, there are a number of details that don't work out here. Combat wings usually aren't trying to turn 5' radius turns at 55mph. Those babies really are overpowered for sure, whereas the stunt models back in the day were close to 60" wingspan models behind Fox .35s that were tuned to run rich, not at peak power. Nothing close to overpowered. The 4cycle-2cycle run only kicked into 2cycle after the g-load went up.
As for wanting the tips to stall, that would blow the quality of the corner and your score would be trashed. You really did not want your control line stunter tip stalling at every corner, not if you wanted to win. Since the inboard tip saw a slower airspeed it was often the first to go as well. It also had the disruption the leadouts and lines provided, although the lines did damp the inside wing, something the outside didn't get. The outside wing was the trouble maker and it going would roll your plane at you, also not what you wanted. You didn't get away with anything and for sure you didn't want tip stalls. They ruined your score and your day. A stunter staggering around the sky didn't win. You didn't get snappier performance, you got a model that lost direction, control and speed when it tried to snap.
During my years of competitive stunt flying, the ST.46 showed up but you really didn't see it on Nobler sized models.[/qupte]
Last time I was at control line combat, no one was using a wing such as you guys describe. Everyone was using constant taper, constant airfoil properties.
As for combat wings, they went through a number of fads when I was messing with them, but trying to get them to tip stall was never one of the tricks. Slowing down in combat really doesn't do a lot for you. Most of the planforms were pure hershey bar. There were a number of 'high aspect ratio' wings that would pop up every so often, but I can't remember anyone touting his design for it's ability to try and snap roll. Combat wings are really locked into a tighter design envelope than stunters are. You seldom saw planform taper that amounted to much. They need wing area and are limited with what they can get away with in span, so the taper percentage seldom was much. They need the lighter wing loading for the same reason stunters wanted it.
The lower the weight of the model and the lower the wing loading, the less lift needed to turn the sucker when the g-load hits like a ton of bricks.