RE: Unusual interference
I had the same problem with a ducted fan jet (BVM Ultraviper). The radio I was using was a Futaba 8UAFS with the standard 8 channel FM receiver.
I tried all, or at least most of, the suggestions already made to no avail. It was a big mystery to me and to everyone else that assisted in trying to solve the problem. Especially because the same receiver was also being used in another DF jet that had the exact same fan unit, engine, pipe, etc., with no problems whatsoever.
I never found what was causing the problem but when I switched to a PCM receiver, the plane flew fine and never experienced another glitch. Problem was undoubtedly masked by the change to PCM.