ORIGINAL: jrf
If it happened in the air, it had to be elevator flutter. There are books written about how to avoid flutter, but the basics are strong servos, stiff pushrods, minimum throws with maximum servo ATV and slow flying speeds.
Jim
think you got it. Think with the bad google translation he used he was referring to it falling off and how to avoid it.
Yashung - rebuild it and refer to jrf's post about how to avoid the problem
good luck and welcome to the forums
