i just got a kestrelll 500 coaxial and i have problems. i have the throttle on full and it hovers about a foot off the ground only,then about 2 3 minutes into hovering it bolts upwards and usually hits the ceiling. the hobby shop has it cause i want a new one, in case they dont take it back does anyone know whats going on. its done this everytime except the first time i flew it then i recharged and flew it and the problems started.

thanks