] An American official said part of the concern over the
] London-Dulles flights was driven by intercepted
] communications that contained phrases believed to refer
] to British Airways Flight 223, the London-Dulles flight
] that has been the focus of the heaviest American and
] British security. Last Wednesday, Flight 223 was escorted
] to Dulles by American fighter planes, and flights on
] Thursday and Friday were canceled.

This sounds plausible. For September 11th, Atta and Binalshibh and the others used codephrases for their targets. The Pentagon was "the Faculty of Fine Arts." The WTC was "the Faculty of Town Planning." Another interrogated Al Qaeda member who was looking into plans to destroy a bridge, said that he was instructed to use the word "gas stations" when reporting back about the gas cutters that he was trying to obtain.

I'd be very curious to learn more about this story . . .