from the 9/11 Timeline:
September 13, 2001: Saudi Royals Fly to Kentucky in Violation of Domestic Flight Ban Complete 911 Timeline
After a complete air flight ban in the US began during the 9/11 attacks,
some commercial flights begin resuming this day. However, all private flights are still banned from flying. Nonetheless, at least one private flight carrying Saudi royalty takes place on this day. And in subsequent days, other flights carry royalty and bin Laden family members. These flights take place even as fighters escort down three other private planes attempting to fly. Most of the Saudi royals and bin Ladens in the US at the time are high school or college students and young professionals.
The first flight is a Lear Jet that leaves from a private Raytheon hangar in Tampa, Florida, and takes three Saudis to Lexington, Kentucky. Prince Bandar, the Saudi ambassador to the US who is so close to the Bush family that he is nicknamed “Bandar Bush,” pushes for and helps arrange the flights at the request of frightened Saudis. For two years, this violation of the air ban is denied by the FAA, FBI, and White House, and decried as an urban legend except for one article detailing them in a Tampa newspaper. Finally, in 2003, counterterrorism “tsar” Richard Clarke confirms the existence of these flights, and Secretary of State Powell confirms them as well. However, the White House remains silent on the matter. Officials at the Tampa International Airport finally confirm this first flight in 2004. But whether the flight violated the air ban or not rests on some technicalities that remain unresolved. The Saudis are evacuated to Saudi Arabia over the next several days (see September 14-19, 2001).
http://www.cooperativeresearch.org/timeline.jsp?timeline=complete_911_timeline&startpos=1100#a091301phantomflight