As the Mediterranean sun begins to set over Trieste, Italy, in May 1995, Lieutenant Colonel Austin Travis (Kurt Russell) leads a perilous Special Forces mission aimed at retrieving a stolen Soviet nerve agent known as DZ-5 from a stronghold controlled by the Chechen mafia. Unfortunately, the operation is a disastrous failure, setting off a chain reaction of global events that no one could have foreseen. Flash forward three months, Oceanic Airlines Flight 343, a Boeing 747-200, takes off from Athens, bound for Washington, D.C., with over 400 passengers on board, including the notorious terrorist lieutenant Nagi Hassan (John Leguizamo), recently released as part of a risky hostage exchange.
In London, an ominous scenario unfolds as a suicide bomber, affiliated with the imprisoned terrorist leader El Sayed Jaffa, wreaks havoc, destroying a Marriott hotel restaurant and leaving untold chaos in its wake. As the hijacking of Flight 343 begins, Hassan makes demands for the release of Jaffa. To address the escalating crisis, Dr. David Grant (Joe Morton), a U.S. Army intelligence consultant, is urgently summoned to the Pentagon to craft a strategy to regain control of the aircraft.
With a keen intuition, Grant suspects that Hassan has orchestrated Jaffa's capture, intending to use the hijacked plane as a weapon loaded with the stolen DZ-5 nerve agent. The Pentagon authorizes a hazardous mid-air insertion of Travis' elite special operations team onto the 747 with the help of an experimental aircraft known as the "Remora F117x." Reluctantly, Grant and DARPA engineer Dennis Cahill join the daring mission.
As the Remora intercepts and docks with the airliner, Grant, Cahill, and their fellow operatives, including Cappy, Baker, Louie, and Rat, manage to board the plane. However, chaos ensues as tremendous turbulence strains the docking tunnel, prompting Travis to make a heroic sacrifice. He seals the hatch of the 747 just as it threatens to decompress, inadvertently demolishing the Remora and severing their communications.
With scant resources at their disposal, Grant and his team are forced to rely on stealth and creativity to locate the bomb before it can detonate. A stumble on Grant's part inadvertently reveals his presence to flight attendant Jean (character), causing a critical chain reaction that leads them to discover the bomb's remote-controlled arming mechanism.
As U.S. officials release Jaffa in a bid to neutralize the crisis, he contacts Hassan from a private jet to inform him of his imminent journey to Algeria. However, the abrupt cutoff of their call piques Grant's suspicions, indicating there could be more to this hijacking than originally believed. A subsequent revelation of a sleeper agent among the passengers amplifies the stakes, setting the stage for a high-octane confrontation between Grant's team and the shrewd terrorist leader.
As tensions escalate, the Pentagon deploys a pair of F-14 Tomcats from the U.S. Navy, tasked with intercepting the hijacked aircraft. In a moment of desperation, Hassan executes U.S. Senator Jason Mavros (character name not provided) to issue a chilling warning. In a bid for communication, Baker uses Morse code via the plane's taillights to inform the military jets that they are working to defuse the bomb, even as they breach American airspace. Meanwhile, Jean spots a suspicious passenger who appears to be wielding an electronic device and alertly notifies Grant, who seizes the moment to confront what he thinks is a threat, only to discover he's just a clever diamond thief.
It’s then that Grant identifies Demou, the actual mastermind behind the hijacking. Their physical confrontation escalates as Grant struggles to gain control of the bomb's detonator, while Hassan tries to eliminate him with gunfire — only to end up on the receiving end of a shot from a vigilant air marshal onboard.
As the commandos infiltrate the cabin, a fierce gunfight breaks out. Grant fights doggedly to procure the detonator from Demou, while Baker and Rat expertly neutralize several terrorist threats. Louie plunges into the melee and ultimately brings Demou's life to an end but not before Demou manages to arm the bomb under duress. Just in time, Cappy and Cahill rush in to disable the explosive device as the 747 stabilizes after a chaotic decompression event triggered by gunfire from the terrorists.
In a shocking turn, Hassan takes control of the aircraft, murdering the pilots and jeopardizing the lives of everyone on board. In a moment of heroism, Rat shoots Hassan, putting an end to his reign of terror. With the lives of the passengers precariously hanging by a thread, Grant, despite his limited flying experience and questionable piloting skills, takes on the monumental task of landing the 747 at Dulles International Airport. In an initially disastrous attempt, he miscalculates his approach. However, refreshed by memories of his training at Frederick Field, Grant reorients himself with Jean’s assistance and successfully executes a safe landing.
As the passengers are evacuated, Grant receives deserved respect from Baker, Louie, Rat, and Cappy for his commendable leadership. However, his journey is not yet over as he is promptly summoned back to the Pentagon to account for his actions in this harrowing ordeal.
