I was thinking about this, and whenever I crash land (rather often) I always leave a very bomblike crater. With the level of modding the there is today couldn't we make a ground crash texture where the plane actually leaves a goughe in the earth, dependant on how far the plane skidded and etc.
That's more complex than you think. Not in terms of the physics to calculate the length and depth of the gouge/crater, but in terms of making any part of the terrain mesh modifiable in real time. That would require either a small map and relatively slow moving objects or else some seriously scary computer power.
As far as I know, there isn't any simulation which accurately models modifications to the earth in real time (e.g., wheel ruts, bogging down in mud, digging, bomb craters).