2slow2matter, i acknowledge your comment about wrong model selected before takeoff, and i agree that is a problem often occuring. But in the case i mentioned above , the flyer only has one model, and had already flown 2 flights successfully. To clarify the situation, he had his phone sitting on his lunchbox, and the transmitter resting against it. After refueling he reached behind himself, turned on the transmitter, and then the aircraft, proceded to start the motor , picked up the transmitter and carried the model to the center of the strip. Upon throttling up the problem occured. So the only criteria that could have caused the drastic change in his controls was the close proximity of the transmitter to the phone.