The film, adapted by William C. Anderson from his own 1980 book of the same title, is Based on a True Story about the controversial (and very costly) rescue of U.S. Air Force Lieutenant Colonel Iceal "Gene" Hambleton (Hackman), after he survives being shot down over Vietnam, finding himself directly in the path of the North Vietnamese Army's Easter Offensive of 1972.
Hambleton is an electronic warfare specialist who spends his time playing rounds of golf when not monitoring an instrument panel "at 30,000 feet with a cup of coffee" in front of him. But while flying a reconnaissance mission for an upcoming bombing strike, Hambleton's plane is shot down deep behind enemy lines and in the middle of the area to be carpet bombed the next day.
He spots a small propeller driven plane nearby and via emergency radio he is able to contact its pilot, Captain Bartholomew "Bird Dog" Clark (Glover), who attempts to guide him to safety from the air. On the run fron the NVA and the impending air strike, Hambleton sees the horrors of war up close for the first time, and must rely only his wits and a voice on a radio to keep him alive.
The film contains examples of the following tropes:
- Abandon Ship: Hambleton punches out when the plane he is riding in is hit by a Surface to Air Missile. He is forced to watch helplessly as the plane explodes before any of the other crew can escape.
- Action Film, Quiet Drama Scene: Many as Hambleton copes with seeing war for the first time from ground level, mostly in the form of his radio communications with Bird Dog.
- Badass Bookworm: Hambleton is a very experienced electronics warfare officer. The fact that the Communists would very much like to capture him and find out what he knows is a large reason why the Air Force attempts a very risky and ultimately very costly operation to retrieve him.
- Bunny-Ears Lawyer: Sgt. Rumbaugh is a hippie who is into a mix of religions, meditates next to the runway, recites mantras, and splashes water from his canteen in the sign of the cross on the windows of departing planes, but is an outstanding mechanic who keeps his pilot's aircraft in top shape at all times.
- Chekhov's Skill: Hambleton is an avid golfer, having memorized the layout of some of his favorite golf courses. This is used to allow Hambleton and his rescuers to communicate when they know the enemy is listening in on their radio transmissions.
- Cool Plane: The Cessna O-2 Skymaster. With a twin-tail fuselage, push-pull dual propellers and gleaming white paint job, it looks extremely out of place in a jungle battlefield. But it is small, maneuverable and takes quite a pounding as the movie progresses.Carver: "Typical FAC pilot, labors under the delusion that he is the most Sierra Hotel cowboy in the Air Force. The truth is he flies a fuckin' VW Microbus with wings."Clark: "This 'VW Pilot' flies 'ten feet' off the deck and draws fire from AK's and SAM's down to eight-year-olds with slingshots and pebbles."
- Death from Above: the film's climax comes in the midst of a massive airstrike.
- Ejection Seat: How Hambleton escapes the doomed EB-66. The other crew members are not so lucky.
- A Friend in Need: Captain Clark's rationale for his heroic efforts to save Hambleton. At first he's just doing his job, but the more he talks with Hambleton over the radio, the more he feels what Hambleton is going through. By the end, he's no longer just doing his duty.
- Heroic BSoD: Hambleton has a few including breaking down into tears after killing a villager who caught Hambleton stealing food, and after the rescue chopper coming to save him is shot down and a village is napalmed in retaliation."People keep dying all around me. I'm through killing... I'm through killing."
- Colonel Walker has one after Big Sky is shot down and the crew are killed. Clark finds him sitting alone in the command bunker, slumped over a chair drinking from a bottle of whisky.
- Heroic Sacrifice: Ross Carver, captured by the North Vietnamese, is forced at gunpoint into a minefield to coerce him into giving away Hambleton's position. Carver makes it through, spots Hambleton in the nearby treeline, winks, then turns back into the minefield where he meets his end.
- Hope Spot: The rescue at the village.
- Just Plane Wrong: The part of the "Jolly Green" rescue helo is played by a USN SH-3 Sea King instead of a USAF HH-3 Jolly Green Giant.
- Knight in Sour Armor: Clark and Ross are shown to be this in the conversation they have in the bar. Both are cynical about the war effort and wonder if rescuing soldiers on the ground is worthwhile since they will likely just get sent back out to the field to be shot at again. But the same conversation reveals both men have done and will continue to do everything possible to save men trapped behind enemy lines.
- My God, What Have I Done?: Hambleton, after killing a civilian in self-defense, especially after the man's wife and son return to see him standing over the dead man's body.
- Plane Spotting: The movie includes quite a few aircraft from the Vietnam War, including UH-1 Hueys, HH-3 Jolly Green Giants, the O-2 Skymaster, and the EB-66 Destroyer.
- Retirony: Captain Clark has a picture of his wife and kid in his cockpit and is due to rotate home in two weeks. Averted in that he survives.
- Roaring Rampage of Revenge: Several in rapid succession after the Jolly Green is shot down and the entire crew is murdered. Hambleton draws his pistol and blindly charges the enemy. Bird Dog fires his white phosphorous marker rockets, and Cobra Leader orders an air strike on the enemy forces even though he is advised that women and children are being used as human shields.
- Screw the Rules, I'm Doing What's Right!: Because of an impending air strike, all rescue operations are grounded. Clark goes back in anyway.
- Shoot the Shaggy Dog: The HH-3 Jolly Green Giant chopper sent to rescue Hambleton is shot down, and the crew are killed.
- Title Drop: BAT 21 is Colonel Hambleton's crew code and how he identifies himself whenever communicating with his rescuers.
- Trapped Behind Enemy Lines
- Unusually Uninteresting Sight: The first scene of the film is Hambleton and another officer casually teeing off on a golf course, as a very large helicopter slowly comes in for a landing immediately behind them.
- War Is Hell