Many years ago I was watching the air display at Mildenhall with my father. We had ridden over on his BMW R100, and found a good viewing spot on some waste ground just off the RWY 29 threshold (along with dozens of others, I might add...). One of the display participants was a Rockwell B1 Lancer supersonic bomber. It carried out a "dirty" approach, which every one had their cameras ready for. Then it disappeared, and things went quiet. Unlike all the others I kept an eye out to the east, just in case... I spotted a dot in the distance which RAPIDLY got larger. I tapped dad on the shoulder and he turned round just in time to see it come in at 50ft (or so), wings swept back, and I guessed, doing 400-500 knots. Suffice to say there were a lot of expletives uttered moments later!