Problem with range check. My radio, tower hobbies computer 6 ch.72 , calls for the range check to be 100 ft. My plane, u can do, will only check at 50 ft.. flutter in elevator and rudder after that distance, wing not on plane durning check. I have tired 3 receivers and all do the same thing. I removed the receiver from the plane and laid it next to the plane with wires hooked up and receiver antenna out too. Still the same flutter. I set another plane next to the u can do, hooked up the servos to that planes receiver and guess what, the same flutter. The servos are spectrum 821 digital they came out of another plane that flew well. I have a servo reverser installed because of the split elevator. I removed it and hooked up the servos to the receiver still outside the fuselage and guess what, the same thing . My transmitter works well with all my other planes, no flutter, even with planes with the same receiver and servos. Any ideas would be helpful, thanks polkfam.