A major airport's tower goes dark in a snowstorm, and a sky full of holding airliners is presented as having nowhere to go and no one to talk to. The film's instinct is correct — instrument approaches and runway lighting really are what stand between weather and the ground — and its conclusion is wrong in five separate, instructive ways. This one is a syllabus.
Finding 1 — You cannot move the ground by softwareThe film's centrepiece has the villains re-transmitting an instrument landing system with the ground reference shifted, guiding an airliner to land below the actual runway. An ILS glide path is not a number in a computer; it is a fixed radio beam generated by a physical antenna array beside the runway, and in 1990 it was a stubbornly analogue one. Even granting the impossible re-aimed beam, the crew has independent witnesses: a radio altimeter calling heights above the actual surface, a barometric altimeter that knows the field elevation, approach lights, and a windscreen. At decision height with nothing where the runway should be, the response is trained to the level of reflex. You go around. The scene needs the crew to ignore four instruments and their own eyes simultaneously.
Aircraft stack overhead for hours as fuel becomes the ticking clock, with diversion never seriously on the table. Every airline flight is dispatched with reserve fuel and planned alternates, and the field in question sits in one of the densest airport clusters on the continent — multiple suitable runways within minutes' flying time. A crew watching fuel approach reserves over a silent airport doesn't circle loyally. They declare minimum fuel and leave. The villains' plan, taken literally, holds hostage the one resource every crew is trained to spend somewhere else.
Seizing the tower is shown to sever the aircraft from the world. But an airliner's radios are radios — the crews could talk to the en-route control centre that handed them over, to the approach facilities of every neighbouring airport, to their company dispatch, and to each other. By 1990 many airliners also carried datalink messaging to their airlines. One facility going silent is a bad afternoon, not an information vacuum. The film needed an island. The frequency spectrum declined to provide one.
The finale ignites a trail of leaked jet fuel that races along the ground and catches a departing aircraft. Jet fuel is kerosene; its flash point sits near 38°C, which is why you can drop a match into a bucket of it at winter temperatures and achieve a wet match. On a freezing taxiway, a thin spilled trail is about the least flammable presentation of the stuff. And even granting ignition, a flame front along the ground does not climb into the sky after an aircraft accelerating away at full thrust. It is the genre's most beloved fuse. It has never once worked.
Trapped in a parked aircraft's cockpit, the protagonist escapes by ejecting. The aircraft in question is a military transport type — and transport aircraft do not carry ejection seats; their crews wear the aeroplane down or wear a parachute to a door. The seat was installed by the script.
More than the film gets credit for. The premise that an airport's approach aids and lighting are critical, attackable infrastructure was genuinely ahead of its time — the industry now spends real money on exactly that concern. The terminology is used with surprising competence: glide slopes, outer markers, and holding stacks appear in roughly the right places. And the dread of fuel state is authentic; dispatchers and crews live with that arithmetic on every winter night the film depicts.
The production understood which systems mattered and then guessed at how they fail. Real failure modes — a missed handoff, a fuel-critical divert into a saturated alternate, a crew flying a raw approach with no lights — are available, frightening, and free. Guessing is the only part that costs anything.