I've never tried what you're doing, so this is really only a guess. With no wheels for ground contact, or flying surfaces (wings, horizontal, vertical), you have no control. In figuring RF is seeing your model setting on the ground with the propeller hitting the ground and bouncing it all over the place. If you're wanting to create a model, follow some of the tutorials that can be found on the forums. At least make some wheels and flying surfaces. Don't forget correct naming of parts as well.