Okay, it's back to school time again, soooo...... Alert- Spoiler- MathemaPhobes should not read past this point:   "Word-Problem"   Crash survivalbility is an important consideration, especially given the high number of G-induced fatalities, in this speedy aircraft. Our main threat here, is brilliantly described by Sir Isaac, 423 years ago, because the kinetic energy goes up as the square of the velocity. If you are going 2 times as fast, as compared to your FAA certified 62 mph'er, when you hit the ditch, or barrier at the boundary of your emergency farmer's field, 4 times the forces must be disipated. 10-20 Gs in the X direction (eyeballs out) is the limit of survivable crash forces.    Scenario: On takeoff, I checked all the multi-engine monitors in the green, the FF hit 44 gph as I rotated and all seemed well, even though I briefed and reminded myself of a very low "abort threshold". If everything went well in preflight (did I sample both tanks for water, strainer, and operational fuel valve?), taxing, and runup, what are the odds of something catestrophic happening, in a properly maintained, firewall forward, certified engine?   Well today it did it, started sputtering at 850 feet, and quit completely just as I finished lowering the nose for glide, switching tanks, cycling mags, low boost then high, twidling the knobs.... NADA. Now I've got 450 feet AGL and a nice 1000 foot farmers field 18 degrees to the left. If I just clear the fence, on this end, and get full flaps touchdown at 89 KIAS (std day). MAGS, master, valve off, land, pop the door? (wait... is the gear up or down- which is better?) Do you hold it off for a smooth touchdown in ground effect, or plant it like we learned for short runway ops? At 70 KIAS = 60 Kt GS = 30 meters/ second, how much distance do I need to survive this today?   Hints:  KE= 1/2 m v^2   1 G = 9.8 meter/sec^2   10 G = 98 meter/sec^2   Newton:  F = m a = KE/d    or  KE= m a d   (mass drops out ! )   Bonus question: What if my choices are water (ditching) vs unfriendly rocky beach vs trees?   Remember, the most important crash survivability criterion is prevervation of the space around the human, properly restrained. Would airbags help? I don't have enough data. How 'bout 4 -5 point restraint - probably, but is there any data from certification testing on the ES to Columbia to Cessna 400 certification?   hmmm