"Gilmore, the captain of that Boeing 757 flight on July 26, 2001, never has told his story publicly. His memory conflicts with an FBI timeline of the 9/11 assault, but Gilmore insists on his narrative and describes it in great detail. He is just one of several witnesses who say they saw the mastermind of the attacks on New York and Washington while the clock ticked toward the largest terrorist attack in U.S. history."

https://www.forbes.com/sites/realspin/2016/09/10/delta-captain-recalls-flying-with-terror-mastermind-just-before-911/#4e42ef5f5156