I don't think I'd be too worried about the forces that that little plane will exert. We have an archaic trainer style plane rigged up with a glider launch on top of the wing at our club. I've only seen it used once at last years air show. The glider wing was considerably bigger than the 'tow' plane and though awkward looking it didn't seem to fly that unusually at all..... I do agree with the release mechanism being foolproof though...that could get nasty.