American Airlines Flight 77
The hijackers went into the cockpit and made the passengers move to the back of the plane less than 35 minutes into the flight. Hani Hanjour, one of the hijackers who was trained as a pilot, took over the flight. Passengers on the plane were able to make telephone calls to loved ones.  They also called people to tell them what was happening on the plane.  The hijackers did not know that passengers were doing this.