One of a number of films to list Clint Eastwood as its producer, director and star, Firefox is a brilliantly implausible action thriller that sees former US Air Force Major Mitchell Gant infiltrate the Soviet Union to steal a state of the art MiG-31 fighter jet.

Made while Eastwood was at the height of his fame, it isn’t necessarily the most fondly-remembered of his 80s productions, but it certainly didn’t hurt the film legend’s career, and it’s got its curiosity value as a product of the Cold War’s final years. Here are some facts you might not have known about the high-flying espionage thriller.

20. Its story was inspired by a real-life Soviet defection

Firefox drew inspiration from a real-life event from world news in 1976. Author Craig Thomas was inspired by the tale of a Russian fighter pilot called Viktor Belenko who defected to Japan. Belenko told the Japanese a number of different pieces of top-secret information.

In addition, the former Soviet pilot even handed over his MiG-25 Foxbat fighter jet for them to study. At the time, this supersonic interceptor and reconnaissance bomber was the fastest aircraft of its kind.

19. There are at least four different versions of the film

The initial cut of Firefox released to cinemas in 1982 clocked in at 137 minutes. Not long thereafter, Clint Eastwood re-cut the movie to remove 13 minutes of footage, presumably in reaction to the widespread complaints about how slow-paced the film was.

However, it didn’t stop there, as the film was re-edited yet again when it came to TV and video. An extra 16 minutes was added to the version of the film broadcast on US television.

18. There is no such thing as a MiG-31 Firefox

The original novel from which Firefox was adapted was inspired in part by a real plane: the Soviet MiG-25 Foxbat fighter jet. If you’d assumed that the plane which the novel and movie is centred on is also a real aircraft, we’ve got some disappointing news for you.

Unfortunately, there is no such thing as a MiG-31 Firefox, the novel and film’s Mach-6-capable stealth interceptor aircraft. The jet in the movie had a more futuristic design compared to the novel and was also influenced by rumours about upcoming real-life stealth fighters.

17. The plane doesn’t fly until 89 minutes in

Firefox is generally remembered as one of the great high-tech aircraft-based adventures of the 80s. If you haven’t seen the movie in a while, though, you might be surprised by how long it takes to get up in the air.

In fact, the super-plane of the title doesn’t appear on camera until 74 minutes in – and Eastwood’s Mitchell Gant doesn’t take off in it until about another 15 minutes after that. Up to that point, Firefox is very much an understated, slow-burning Cold War spy thriller. The bulk of the running time follows Gant in his stealthy mission behind the Iron Curtain, whilst it’s only in the last 45 minutes that it gets airborne.

16. Back to the Future Part II reuses footage shot for the movie

Firefox might not spend quite as much time in the skies as you might expect, but they still shot a whole lot of sky-bound footage for the movie. In fact, they shot enough excess footage for some material they didn’t use to eventually show up in another hit movie.

1989’s blockbuster sequel Back to the Future Part II features footage that was originally shot for Firefox. The opening titles of the blockbuster sequel feature the DeLorean time machine taking flight through a cloudy sky, utilising unused camera angles from Firefox created by special effects house Industrial Light and Magic.

15. $20 million of the film’s $21 million budget was spent on special effects

Firefox was Clint Eastwood’s ninth film as director, and the seventh occasion on which he’d directed a movie whilst also playing the lead role. The film was produced by Eastwood’s own company Malpaso Productions, and it was the biggest production they’d ever taken on with a budget of $21 million, which was still a huge amount of money back in 1982.

As hard as this might be to believe, it’s said that $20 million of that budget was spent solely on the film’s special effects. To handle the high-tech aviation sequences, Eastwood hired John Dykstra of legendary FX house Industrial Light and Magic, the team behind the Star Wars movies.

14. A full-size replica plane was built for the film

While Firefox’s FX were state-of-the-art at the time, this was still before the days of CGI. As such, while some sequences use special effects and miniatures, others had to be done more-or-less for real.

For this purpose, the production needed at least one Firefox model that was life size. When we first see the secret super-plane in the Soviet hangar, that’s a real, full-sized replica. This impressive prop measures in at 66 feet in length, and 44 feet in width.

13. One of the replica planes crashed into rush hour traffic

As well as having one life-size Firefox, the FX team built three smaller models too. At least one of these model planes was flown the old-fashioned way: using a remote control. However, at one point during filming something went seriously wrong with the remote-controlled model.

According to Clint Eastwood, one of the remote-controlled planes at one stage crashed into a busy road. This little production mishap wound up causing significant delays for local commuters during rush hour.

12. Most of the Russians are played by English actors

When it comes to casting Russians in American movies, it’s long been routine for Hollywood to turn to English actors. This is certainly the case in Firefox, where outside of Eastwood’s All-American USAF pilot, the bulk of the characters are Russian.

A number of respected British thespians show up in Firefox, probably the most famous being Nigel Hawthorne. It was one of the comparatively few Hollywood roles taken by the late actor, who later appeared in Demolition Man and The Madness of King George.

11. A Firefox helicopter also appears in Blue Thunder

As an 80s movie centred on a high-tech aircraft with an iconic tough guy at the helm, Firefox is frequently mentioned in the same breath as Blue Thunder. That 1983 thriller (later the basis for a short-lived TV show, which struggled to compete with the similar Airwolf) stars Roy Scheider as an LAPD helicopter pilot recruited to take the controls on a super-advanced helicopter.

There is a direct link between the two movies, as the same helicopter makes an appearance in both. The aerial action sequences in Firefox see the MiG-31 pursued by a Soviet helicopter gunship. The cockpit for this helicopter is that of an Aerospatiale Gazelles, which is the same model used in Blue Thunder.

10. Future Cheers and Pixar star John Ratzenberger makes a cameo in the film

While the bulk of the supporting roles in Firefox are taken by Brits, at least one notable American actor makes a brief appearance. John Ratzenberger, best known at the time for his small role in The Empire Strikes Back, appears in Firefox as a USAF engineer, Chief Peck.

Later in 1982, Ratzenberger would become a familiar face for portraying Cliff Clavin in beloved sitcom Cheers, which ran for nine years. Ratzenberger appeared in 270 episodes, as well as reprising the role of Cliff in episodes of Wings and Frasier. Since then, he’s been a regular voice actor for Pixar, taking minor roles in most of their films.

9. Eastwood’s fight scene also features in Trouble with the Curve

Back to the Future Part II is not the only movie to later make use of footage shot for Firefox. The same thing happened on 2012’s Trouble with the Curve – one of the few movies since the 80s which Eastwood acted in, but did not direct.

Director Robert Lorenz’s film casts Eastwood as an ageing scout for the Atlanta Braves baseball team, alongside Amy Adams as his daughter. The film deals with the elderly man’s struggle to keep up in the modern world, reflecting on his younger glories. For flashback scenes featuring Eastwood’s character as a younger man, fight footage from Firefox was utilised.

8. Eastwood previously played a pilot in 1955’s Tarantula!

Most of us can think of plenty of movies in which Clint Eastwood played a cop, a soldier or a cowboy. However, Firefox marks one of the only times in which the film legend portrayed a pilot. Could you name the one other occasion before Firefox on which Eastwood was put behind the controls of a fighter plane?

If you couldn’t answer that question, don’t feel bad; it’s not one of the films Eastwood is most closely associated with. The actor first portrayed a pilot in 1955 creature feature Tarantula!, which was one of the actor’s first roles along with Revenge of the Creature (the sequel to The Creature from the Black Lagoon).

7. Critics hated the film

Firefox proved to be a respectable commercial success, but it didn’t go over so well with the critics. Vincent Canby from The New York Times wrote that ‘Firefox is only slightly more suspenseful than it is plausible. It’s a James Bond movie without girls, a Superman movie without a sense of humor.’

Famed critic Gene Siskel said that while the film was “generally entertaining, (it) would be a lot more so if Eastwood… had excised some of the laborious buildup to the final shootout.” Writer Howard Hughes lambasted the film as ‘less a Firefox, it’s more of a damp squib, or at best a smouldering turkey.’

6. It was adapted from a 1977 novel by Welsh author Craig Thomas

Firefox is based on the novel of the same name by the Welsh author Craig Thomas. It was the second novel from the former grammar school English teacher, and was first published in 1977.

Thomas took inspiration from true stories which he’d been told by some ex-RAF friends. The book’s sales were boosted by the film, leading Thomas to later write a sequel which he entitled Firefox Down. This follow-up novel was released in 1983, and Thomas dedicated it to Clint Eastwood.

5. Clint Eastwood directed and starred in another film that year

Clint Eastwood has never been one for resting on his laurels, and seems to like keeping busy. This much was evident in 1982, when the screen icon both directed and took the lead roles in two movies back-to-back. On top of Firefox, Eastwood also made a very different film that same year entitled Honkytonk Man.

A drama set during the Great Depression, Honkytonk Man was adapted from Clancy Carlile’s novel and cast Eastwood as a struggling country and western musician. The film failed at the box office, taking barely $4.5 million worldwide, but it was largely well received by critics.

4. Issues behind the scenes caused Clint Eastwood to suddenly stop working with his editor of ten years

As the large number of alternate cuts might indicate, the editing process on Firefox was a difficult one. It would seem that behind-the-scenes difficulties had a professional and personal impact on those involved. After work was completed on Firefox and Honkytonk Man (Clint Eastwood’s other 1982 production), Eastwood never again worked with editor Ferris Webster.

Up to that point Webster had worked closely with Eastwood, editing most of the star’s previous films. We don’t know why Eastwood made this decision, but according to Eastwood’s production company partner Fritz Manes, Webster “died brokenhearted.”

3. It was one of the highest-earning films of 1982

Firefox certainly wasn’t Clint Eastwood’s biggest hit with critics or audiences, but it still performed pretty well commercially. By the end of its theatrical run in 1982, the film had earned just over $46.7 million (adjusted for inflation that’s around $143 million today). This was a respectable sum for the time, given the film cost $21 million to make (and doubtless a bit more to market).

Firefox wound up the 15th biggest film at the global box office in 1982. Eastwood’s biggest ever hit as leading man is, believe it or not, 1978’s Every Which Way But Loose (yes, the movie with the orangutan) which earned $328 million adjusted for inflation.

2. It was Clint Eastwood’s first film as producer

Clint Eastwood, as we’ve established, is a bit of a jack-of-all-trades when it comes to the movies he works on. Firefox marked the seventh time on which he had both directed and played the lead in a movie. However, this film also marked the first time that Eastwood took on another key responsibility behind the camera: producing.

Firefox gave Eastwood his first credit as full producer, a role he has repeated many times since (including his Oscar winner Unforgiven and Million Dollar Baby). Prior to this, Eastwood had served as executive producer without credit on a number of his biggest hits, such as Dirty Harry and Coogan’s Bluff.

1. Atari produced a state of the art arcade game based on the film

In 1984, two years after the film hit cinemas, a Firefox arcade game was released by video game pioneers Atari. The Firefox arcade game utilised state-of-the-art LaserDisc technology, making it the first and only Atari game to do this.

A first person flight simulator and shooter, Atari released the game both in upright and sit-down cabinets. The game featured unused first-person footage from the film that was shot by helicopters flying over Scandinavia and Greenland.