It will be hard to say ... my SU31 does that a lot and I could not get to the bottom of it. On another set up I got it bad and I lost 3 planes ... found out my 'glitch' was caused by my RX antenna being cut in half (always make sure you have something to take the strain off the antenna, use a button or old horn to keep the antenna being pulled out of the plane). That causes low range and when the ends touch it causes a glitch. Just my 2 cents ...