I was at a friends farm out in West By God Virginia. We heard a jet aircraft sound that just went on and on and on. Looked around, and no aircraft to be seen ???? Suddenly from over the ridge behind his house a C5A popped up. Scared me pretty well, as he did not clear the ridge by more than 100ft, and the ridge is not that tall behind the house. I could see the aircrew in the cockpit clearly. I guess they were doing some "nap of the earth" practice, but I had no idea that they did that in aluminum overcast like that. Very Impressive!