On Coastal Airlines' maiden flight of the Starquest airliner, passengers are treated to the most sophisticated and enjoyable flying experience to date, led by pilot Joseph Franklin, Scott Valentine. Special Agent Gina Vitale, Lindsey McKeon, is aboard to shield Franklin, who is also the President's brother. Back at the Franklin household, intruders sneak in, murder the housekeeper, and abduct his wife and children. A cadre of ten neo-Nazis, who have smuggled guns onto the flight, force their way into the cockpit, killing the navigator. Agent Vitale makes it into the cargo hold and contacts her home base.
Robert Stevens, Geoff Meed, the leader of the assault, forces the pilot to contact his sister, President Harriet Franklin, Meredith Baxter, and demands that ten members of his Argus Aryan Brotherhood be released.
A squadron of Lockheed Martin F-22 Raptor fighters tails the hijacked airliner, but one is destroyed in a fuel dump. When the autopilot malfunctions, the Starquest plunges toward the city before pulling out of the dive. Willie brings a flight attendant to the cargo hold, but Vitale encounters him and kills him. Other terrorists shoot a flight attendant, thinking she is the sky marshal.
With an FBI SWAT team at the isolated cabin where Joe Franklin's family is held, in the White House, President Franklin orders the activation of "Kittyhawk," a satellite-based system that can remotely control aircraft. As the airliner spirals toward disaster, she faces a life-or-death choice between her own family and the safety of countless civilians below.
In the cargo hold, Robert reveals the hijacking is a front for a bank heist. Vitale confronts him and he triggers an explosion, which not only kills him but also slices off a cargo door, tearing away a jet engine. As Starquest hurtles toward Washington, the order to shoot it down proves ineffective when the plane's automated defenses kick in.
Ultimately, the Sky Marshal, Peter Smith, is killed while Vitale and her team fight to retake control of the aircraft. With the Franklin family rescued, the President makes one final, desperate attempt to bring the Starquest down. A new satellite-based laser fires, destroying one of the trailing F-22s. She then tells her brother to do what remains: pilot the Starquest to a water landing on the Potomac River in Washington, D.C.