Yeah, I agree it must have something to do with the forces on the model. I loved playing with these things way back when (1960s) - the most frightening one was

Yeah, I agree it must have something to do with the forces on the model. I loved playing with these things way back when (1960s) - the most frightening one was a model attached to a jetex rocket engine https://en.wikipedia.org/wiki/Jetex https://en.wikipedia.org/wiki/Jetex which after taking off immediately immolated itself, which I suppose is par for rocket powered aircraft, of any size.