|On 27 November 2009 PilotsFor911Truth.org published a simple fact about the flight of Flight 77 which makes a conventional hijacking scenario impossible - according to Flight Data provided by the NTSB the Flight Deck Door was never opened in flight. The status of the door was polled every 5 seconds from 12:18:05 GMT to 13:37:09 GMT, and each poll logged the door as closed (a CSV file of the log can be downloaded here).
No-one entered the cockpit of the plane during the flight, therefore it was not flown into the Pentagon by an Arab hijacker.
What caused Flight 77 to hit the Pentagon? Electronic hijacking is a strong possibility...
Link to electronic hijacking article. http://www.public-action.com/911/robotplane.html