</font><font color="blue" class="small">( RoyJackson,
That is WILD !! Back tires stationary & the tractor just does a 360 degree flip. )</font>
It would only actually be a 180 degree flip. The ground would prevent it from going any further. Although unlikely, because the operator would have to do several things wrong, it is certainly possible. I happened to go get a tractor that had been stuck the day before and this nearly happened. Fortunately the "doesn't feel right" part of me kicked in. The engine really, really lugged and it wouldn't move. I applied more power and went to slip the clutch more and it still wouldn't move. I then went to the lowest gear range and lowest gear and each time I went to let the clutch out the front raised. Weird! Each time I'd jam the clutch back down and the front would slam back to the ground rather violently. It took me 2 or 3 trys before I realized what was going on. I'd never heard any story about this before, but I figured out what was happening and didn't mash myself.
I suppose if the tractor had enough power and you just dumped the clutch it could go over relatively fast. Or, if you didn't have the reaction to jam the clutch down when the front slowly raised in low gear, low range, you could go on over. Maybe I was fortunate, but when it just "didn't feel right", I got off and began thinking about the situation.