Pilot error covers a multitude of sins of ommission. Poor or non-existant preflight, battery not properly charged, servo used and abused for to many airplanes over to many years...and the list goes on and on. I have been guility of all of these and more, but, I had , over this past summer, two radio glitches that I could never explain. One with a Futaba 8UAFS and the other with a JR 10X. I could never duplicate either of the glitches but they happened nevertheless. One was a glider at extreme altitude and the other was a power plane on takeoff. Pilot error? Not this time...