I have a problem with my Blade. Durring flight the helecopter surges up and down, even when indoors. Is this what happens when the collective pitch sticks? Or is it an electrical problem, like glitching or a bad servo? I did notice that the part where the flybar is has a lot of play and it doesn't slide up and down on the rotor head freely under load. I have over 50 suscessful flights and this problem developed on its own, not as a result of a chrash.