Aus 9/11 Wiki
On a Metro train just pulling into the Reagan National Airport Station. (See also Carroll, Susan)
"I was just pulling in on the subway station just at National Airport. I just happened to look over - actually my back was facing in the direction of the Pentagon - I looked to the right of the train as we were coming into the station, and noticed a jet flying in real low, about a mid-sized passenger jet flying in. I know it was silver, that's the only thing I know."
He could not see anything.
Source List: Bart