errrr........ I can say blew itself apart, first let me note ALL props are balanced, upon rest with my Son on the hood of my truck he wound up the RPMs and noticed one motor vibrating badly,?????? went inside and mounted my 9x4 props which are I know were balanced nicely, installed the props and not bad pretty smooth the cranked it full throttle and BOOM!! all I can think is a resonate vibration met a frequency and it came apart, even busted all the body mount screws off, dang I said, just ordered a new body kit. I know, hoki landing gear till my new legs get here. after repairs YIPPIE!!