I bought an UM Spitfire last week, out of the box the ailerons didn't work. Back to the hobby shop (hour drive one way) yesterday and they replaced it no problem. Earlier today I tried it out and it looks great but feels very weak, I had a hard time getting it to climb. I landed to check everything and put a fresh battery and when I tried to take off it wouldn't get more than 10 feet off the ground. I landed it and put it away for now, any ideas?