Woody.....Cud be low battery in either radio or reciever. Cud also be that your antennae wire was too close to a servo or control rod (if they are the wire type) and caused interference. Make sure your antennae exits the plane behind the canopy or is enclosed in a tube thru the rear of the plane. Always test your batteries before you fly. I check them every 2-flights. I also make sure no one else is on my channel !!