weird

I challenge you guys to build a "EKIP Tarielka" That Russian thingy looks like this: Its cross section looks like this: And here's a video of it flying, just to prove that it works: https://youtu.be/GNn1rVJeM08?t=7m10s

Hello there, A friend of mine recently got his first plane: the Delta Ray. We fly together whenever we can, but a few days ago something weird happened. After a regular landing, my friend picked up his plane, and when he turned on his transmitter (he had turned it off after he landed), 1 motor...