Gerard Holmgren searched the Bureau of Transportation Statistics online database, learned that American Airlines Flight 11 and Flight 77 were not scheduled for September 11, 2001, and wrote about his findings here:
The JPEG files below are partial copies of the American Airlines flights leaving Boston's Logan Airport and Washington DC Dulles Airport on September 11, 2001, produced on March 14, 2007, using this database:
As of March 14, 2007, Flight 11 and Flight 77 are now listed in the database, each with a scheduled departure and scheduled elapsed time listed, but with no actual departure time and no "wheels off" time. The tail numbers are also not listed.
Other planes scheduled to depart after planes were grounded that day have the same data listed, including the lack of a tail number But Flight 11 and Flight 77 supposedly had an actual departure time and a wheels off time, so why are these not listed, along with the tail numbers?
It does not seem to be because they crashed, because United Airlines Flight 175 and Flight 93 have this data listed in the JPEGs below, produced from the same BTS database. The only difference between Flights 175 and 93 and the other planes that got off the ground is that 175 and 93 do not state actual elapsed flight time.
Flight 11 - click to enlarge and read or print.
Flight 77 - click to enlarge and read or print.
Flight 175 (page 2 of 3) - click to enlarge and read or print.
Flight 93 (on page 2 of 2) - click to enlarge and read or print.
Killtown compiles a variety of data about the flights, airplanes, and passengers here: