Are the wings meant to be like that??

[Air Force One]

The FT Simple Soarer was beautiful, I did around 10 successful glider tows with it. But DO NOT TOW WITH THE STOCK WING. I had a major accident today when I used a foam spar for the glider wing. My friend was towing me up in his Durafly Tundra, I was in the simple soarer. A gust of wind came and the glider flipped over. The glider wing folded (much like David's glider in the glider challenge) I didn't have enough time to release and set the Tundra free, so the Tundra required a new fuselage and wings, while the glider needed new wings and a nose. Disappointed in FliteTest's design, none of my other planes with the FliteTest airfoil has failed before, I can only conclude that the large wingspan of the glider made it more vulnerable to folding.
Repair cost: ~160 dollars
Modifications:
1. Only have polyhedral: remove the dihedral and add carbon fibre spars in it.
2. design a new nose that supports a motor AND towing at the same time.
3. add ailerons, spoilers, and flaps.
4. make use of 3S 1300mAh and replace motor/ESC to more powerful 30A setup.
5. use a folding prop instead of a normal prop, increase propeller pitch and diameter.
After all that being said, it is still an enormously rewarding build, but remember, foam spars just don't do the job.

 

[CrashRecovery]

So Let me get this correct. You were being pulled by a far more powerful aircraft and when the fecal matter hit the rotating oscillator the planes crashed. The simple soarer was designed to be a light aircraft, slow flying, beginner plane. Yes it can be pulled up like a glider but you have to remember the power the tundra has out performs the flitetest design for simplicity. If you plan to build one with your suggestions I suggest you scale up. The size of it now would probably hamper what you want out of it. Try going bigger and maybe making a box spar next time and see if it holds up to what you want to do.