Does a outdoor catapult launched glider need wing tip washout?

[stupid]

Does a outdoor catapult launched glider need wing tip washout?

A question from Victor about the Mad Max glider wing needing wingtip washout. I thought I would give my opinion here and to see if others can give their opinion on the need of wing tip washout.

Here is my 2 ¢ on the subject of washout.

   Most model airplane flyers believe that you need washout on your wing tips because they're listening to what full-size airplane designers are doing. Full-size airplane designers are trying to keep the wing from stalling all at once by using washout. The benefit is that if the wings starts to stall it does it slowly giving the pilot, a chance to react to keep the airplane from losing lift and diving, either straightforward or off to one wing tip all but it once.
   There are a lot of differences between full-size aircraft and a catapult launched glider that needs to fly on its own. I'll start off by stating the obvious. I've never had a problem with wingtip stalling on a catapult launched glider. Actually a small amount of wing tip stall is beneficial for the glider to enter into a thermal.. Modern designs of model catapult launch gliders have evolved to being just stable enough and yet be able to fly into thermals.
   The differences between model catapult launch gliders and full-size aircraft are that, gliders have a much lower wing aspect ratio. Due to the slow speeds and need for lift at the lower Reynolds numbers. The lower aspect ratio of the wing lessens the need for tip washout. Combined with the excessive amount of dihedral compared to full-size aircraft even further reduces the need for tip washout.
   When a catapult launched glider is flying and encounters a thermal, the turn that we build into the gliders to circle causes the inside wing to stall first when encountering the thermal. Causing the glider to core into the thermal. If you're flying a model other than a catapult launched glider that has a higher aspect ratio wing, and not as much dihedral that we use, you might want to incorporate some wing tip washout to lessen the full wing stalling effect. Also, if you're flying remote control aircraft, you need to follow more closely to full-size aircraft designs so that you can control your aircraft.
                  Bob

[Rekitus]

I will have to call you Bob.

thanks for the thinking... I learned of washout from a CG gentile lady.

If thermals are hunted... my GL didn't hunt. 
and I learned to avoid tip stalls from a foam wing RC craft.
close to ground to land and slowing... then suddenly the rt tip dropped.
and a cartwheel.  many times...

so I like washout.
I do know it can cost in total lift

part of the curve up can stop tip stalls in any case.

again thank you.

victor