International terrorist Charles Rane (played by Bruce Payne) is on the verge of changing his identity through plastic surgery, hoping to evade capture. However, as federal agents and SWAT teams draw near, it becomes clear that the surgical team is complicit in his escape plan. When Rane's suspicions arise, he murdered the surgeon in a desperate bid for freedom, resulting in a dramatic chase through the streets that ultimately ends with his capture.
Meanwhile, former police officer John Cutter (portrayed by Wesley Snipes) is coming to terms with the traumatic loss of his wife during a robbery. He has taken a new role where he trains flight attendants and security personnel on handling threats, including terrorist attacks. During one such session, he faces off against Marti Slayton, a flight attendant, when she disregards his guidance, sparking a moment of tension between them.
After the class, Cutter meets with an old friend, Sly Delvecchio, who offers him a position as vice-president of the anti-terrorism unit at Atlantic International Airlines, a prominent airline. Though hesitant at first, Cutter is persuaded during a lunch with Delvecchio and the airline’s president Robert Hooks.
Cutter's first flight as part of the team is aboard Atlantic International Flight 163 to Los Angeles—where, unexpectedly, he finds Marti serving as a flight attendant again. Complications arise when Rane, in FBI custody for his previous terrorist acts, is also on board, accompanied by his disguised accomplices. When a headcount is conducted by Marti, Cutter is identified as passenger number 57.
Disaster strikes mid-flight when Sabrina Ritchie, posing as a flight attendant, executes the FBI agents guarding Rane, allowing the rest of his crew to spring into action, holding passengers hostage. Cutter, who was in the lavatory during the takeover, fights back against Rane's men but faces dire consequences when Rane kills a passenger, leaving Cutter burdened with guilt for failing to protect him.
In a tense confrontation, Cutter and Marti flee to the plane's lower deck, where they manage to initiate a fuel dump, forcing their Tri Star Lockheed L-1011 to divert to a small airfield in Louisiana. Although Cutter escapes the aircraft, Marti is captured by Rane's men. On the tarmac, Cutter is apprehended by local law enforcement.
Rane then reaches out to the local sheriff, Chief Biggs, negotiating the release of hostages in exchange for fuel and takeoff clearance. Rane cunningly labels Cutter as a traitor, which complicates matters when the police bring Cutter in front of Biggs, who orders his arrest.
As hostages are released, Rane and his henchmen manage to slip away. However, Cutter, determined to save those left behind, overcomes the sheriff's deputies and commandeers a police motorcycle in pursuit of Rane. Simultaneously, an FBI team arrives, led by Dwight Henderson, who angrily updates Biggs on Cutter’s true identity.
Cutter engages in a fierce battle against one of Rane’s henchmen at a nearby fair and faces off with Rane himself as the police arrive. Rane threatens to execute the remaining passengers still onboard the plane if he is not returned and granted takeoff approval.
In a tense standoff, Cutter coordinates with Henderson and Biggs, crafting a strategy involving FBI snipers to apprehend Rane upon his return to the aircraft. However, the plan goes awry when the sniper’s shots inadvertently hit Rane's escort instead. This misfire allows Rane to evade capture and take control of the plane as it begins its ascent.
In a desperate act, Cutter leaps onto the moving plane's landing gear. Once inside, he takes down Rane's remaining henchmen and engages in a brutal fistfight with Rane. The chaos results in explosive cabin decompression, and amidst the brawl, Cutter gets the upper hand, ultimately sending Rane plummeting to his demise from the open cabin door.
With the plane safely landing in Louisiana for a second time that day, Cutter and Marti finally share a moment of peace as they slip away into the sunset, hand in hand, away from the turmoil they endured.
