I bought a new Hangar 9 alpha trainer RTF, (I have about an hours flying experience, and can take off and land solo). and I have a problem I need diagnosed. Every time my plane takes off, after it gets about 15 feet in the air, I hear an audible "bang" and then the engine begins to sputter. I am getting really good at gliding it back to earth since this has happened to me 3 times.. in a row! So here is what I've done, which hasn't helped. On the ground, I started the engine back up, let it warm up a bit, then while holding the airplane, I have my wife take the transmitter and move the throttle to high. Then engine still works fine at this point. I then take the airplane, and hold it at the same angle as it would be during takeoff. Still no problems, engine is running perfectly. So then I hold the airplane upside down, at an angle, inverted, everything. The engine doesn't skip a beat. So the next thing I do (with the engine still going like crazy, is swing the entire fuselage left and right (trying to see if G forces are possibly preventing fuel from entering into the engine or something similar. You guessed it (other than looking totally crazy swinging around a running airplane, the engine is still working fine.) So I've shut the airplane off, and took a look at the tank. Everything looks great. The clunk is doing its thing, no bends, I even made sure I had the correct line connected to the muffler, and engine. I tuned the engine doing the pinch test, everything works like its supposed to, the engine speeds up briefly then dies. So, I need some help! On the ground the engine will make it easily through an entire tank of gas at full throttle, but as soon as you try to take the thing into the air, its "bang!" and sputter sputter... you get the picture. ANY advice is greatly appreciated, so thanks in advance! Mitch W. Watertown, NY.