Some good numbers above to think about. Has any research been done in to what sort of maximum speeds are practical for deliberately inducing a ground-loop or going in to soft grass or earth? Thinking - that if you see an over-run is inevitable and to continue straight off the end would be really, really ugly, what is there to lose by putting it off the SIDE of the runway at an angle dependant upon what obstructions are in the side area? I have seen it done successfully on wet grass during a landing that was about to over-run, but granted it was a DC3 and only doing about 25 knots when the guy gave it a bootful of rudder and a well-judged squirt of throttle. He actually got it nearly all the way around through 180 degrees, chewing up a couple of cone markers as he went but basically keeping it within the runway confines. On another occasion I saw another DC3 deviate at a near right-angle off the tarmac onto grass, but that one was a crosswind landing stuff-up by a deputy chief pilot who was out of his depth on the old Gooney. Neither incident caused any damage other than skid marks (of both the visible and not so obvious kind!).