CBS News Correspondent Jim Stewart has learned that the surveillance flights were conducted prior to the Sept. 11 attacks. Hani Hanjour, the hijacker who is believed to have piloted American Airlines Flight 77 that struck the Pentagon, conducted test runs in careful preparation for the final attack.
Law enforcement officials tell Stewart they have now confirmed that Hanjour rented small aircrafts in the Maryland and New York areas three weeks before the attacks.
They say he made practice flights using those aircrafts in the vicinity of both the Pentagon and the World Trade Center towers. The purpose of the flights, officials surmise, was to study landmarks and examine possible approach routes to the targets.
Hanjour's flights were disclosed to U.S. interrogators by what one source identified as a "senior detainee." The detainee was not identified by name, although investigators have been closely questioning suspected Sept. 11 coordinator Ramzi Binalshibh, who was captured in a series of raids in Pakistan last month. If Binalshibh is cooperating, it would be a major boost to U.S. intelligence.
The FBI had previously determined that several of the hijackers, including Hanjour and ringleader Muhammed Atta, had traveled as passengers aboard the flights they later hijacked in order to observe crew practices.
Hanjour conducting these practice target acquisition flights is seen as just another layer of preparation. In the words of one official, "These guys were not leaving anything to guesswork."