According to the Bureau of Transportation Statistics, not only did Flights 11 and 77 not take-off on 9/11/2001, but also they were not scheduled to fly that day.

9/11 (7:59 am): Two bags with Mohamed Atta's name tags are on a Portland flight, but are not transferred onto Flight 175 out of Logan Airport. FBI seizes records of students at flight schools. Atta got on the jet from a connecting flight from Portland, Maine. The two bags with Atta's name tags were on the Portland flight, but did not get transferred in time to be loaded on the Los Angeles-bound flight that left Logan Airport at 7:59 a.m., about 45 minutes before it smashed into the World Trade Center tower in New York." - St. Petersburg Times (09/13/01)

9/11 (8:10 am): Flight 77 departs Dulles airport in Washington D.C. in which the Bureau of Transportation Statistics shows no stats for Flight 77 taking off that day, was piloted by Capt. Charles Burlingame who was a Navy fighter pilot and once worked on anti-terrorism strategies in the Pentagon (the same area of the Pentagon that got hit), and one of the many unusual passengers on this flight. See Defend America, BTS statistics for Flight 77, The unusual passengers of Flight 77

2001 September 11 9:39 AM: Flight 93 Hijacker Again Warns of Bomb on Board, Flight Controllers Again Overhear; NORAD Still Not Notified.

2001 September 11 9:49 AM: FAA Headquarters Continues to Delay Decision on Contacting NORAD About Flight 93.

Two Boeing 767's that allegedly crashed into the North and South WTC Towers at approximately the same angle.

Remote Controlled Passenger Airplane Flew Before 9/11, Despite Claims to the Contrary.

Aircraft and flight anomalies

Witness at Flight 93 crash scene says "there was nothing that could 'distinguish that a plane had crashed there." 

Killtown's: Did Flight 77 really crash into the Pentagon?)

Passengers

Passenger death compensation claims raise questions.

Crew and Passenger Manifests:

American Airlines Flight 11

American Airlines Flight 77 - all but one of the passenger bodies were allegedly recovered from a completely destroyed aircraft 

United Airlines 93

United Airlines 175

Pentagon deaths

9/11 - Shanksville, PA, is a military flight corridor.

Witnesses Recall Plane Crash - "A plane going over Shanksville wasn't anything unusual because it is a military flight corridor, said Kelly Leverknight, who lives in Shanksville, just a couple miles from the crash scene." - Daily American (2001)-removed [Reprinted:  local; us-pentagon.tripod.com-removed]

"corridor - Restricted airspace for the passage of aircraft."

2001 September 12: Hijacker's Passport "Found" Near WTC and the black box of Flight 93 was allegedly found 25 feet under the ground in Pennsylvania, and still worked, but the black boxes of Flights 11, 175 and 77 were allegedly not found.

2001 September 27: There were no Arabs on the passenger list of Flight 77, yet the FBI published photographs of the alleged hijackers, a month before the autopsies were done on 11/16/01.