Firefox

You must think in Russian.

1982 Movie adaptation of Craig Thomas' novel, the first real technothriller, starring, directed by and produced by Clint Eastwood. The Soviet Union has developed a new superplane, the MiG 31, called by the Americans "Firefox". It's capable of Mach 6, can't be detected on radar and has weapons launched by thought (but in Russian of course).

There are some differences from the novel, but Thomas fans like the adaptation and Thomas himself dedicated his sequel book Firefox Down to Eastwood.

Note that there is in fact, an actual MiG-31 (NATO reporting name Foxhound) and that it reached service in the same year as the movie reached theatres. It's far lamer than its movie counterpart: the only thing it can do well is go really fast.

Amusing note: when reconnaissance photos of the Firefox's predecessor, the MiG-25 "Foxbat", first came to light, its huge wings and apparent manoeuvrability promised thereby caused a panic in the US military. It was only when a defector brought a copy over that the truth came out: the thing was made of a very heavy alloy, needed huge wings just to get off the ground, couldn't dogfight to save its life and had a very short range. That said, it was very fast, faster than anything modern any air force fields today, and its apparent purpose, high-ceiling heavy interceptor (fast delivery of a missile platform) and reconnaissance bomber duty, did not involve dogfighting. Simply put, it wasn't actually intended to be a fighter.

In the novel, when a character points out the Belenko defection, and resultant false alarm, as a reason not to panic about the "Firefox", another tells him that their information is that the plane is seriously as good as feared.

Predates by two decades and has nothing at all to do with the web browser Mozilla Firefox.

Tropes used in Firefox include:

California Doubling: Vienna stands in for Moscow, for obvious reasons. Hilariously combined with Television Geography - Clint Eastwood enters subway line U1 at Karlsplatz, but gets off at Schönbrunn, a U4 station.
The Can Kicked Him
Chekhov's Gun: A literal example, the rearward-defense pods. Not flares but aerial mines, which he uses to great effect on the second Firefox, destroying it.
Cool Plane
- The Cool Plane, in Hollywood history.
Darkest Hour: Gant manages against all odds to get Firefox to the refueling point on dry tanks, and sees only an empty ice floe. He figures he's going down in the Arctic Ocean for the last time, when suddenly he spots the refueling vessel: a submarine.
Dirty Communists: A narration, by a dissident, of a few Kick the Dog moments are awkwardly tacked in just so you know stealing their plane is the right thing to do.
Everybody Dies / Heroic Sacrifice: Pretty much every single double agent dies getting Gant to the plane.
Fictional Document: The exchange of memos between two SIS agents at the beginning, developing the plan to steal the aircraft.
Gundamjack
Idiot Ball: Gant's explicitly warned to watch his speed going through the Ural mountains to avoid tripping listening posts. What does he do? Opens the MiG-31 up to SR-71 speeds. Results in Crowning Moment of Awesome as everything turns into a blur, but immediately blows the "head-south-go-north" gambit up in his face.
I Owe You My Life: Gant has a chance to kill the Firefox pilot but refuses to kill a helpless, innocent man. In the Firefox-vs-Firefox dogfight later, the prototype pilot returns the favor.
It May Help You on Your Quest: Before he goes to Russia, Gant is handed an ordinary looking radio. He's then told it's a navigational device meant to guide Firefox to a secret refueling point -- and that if he loses it in Russia, he's dead. It doesn't figure in the plot until he's well into his flight at which time he pulls it out and uses it as intended.
It Sucks to Be the Chosen One: Gant is yanked out of his isolated, PTSD-soaked life and thrust straightaway into a spy mission.
Lzherusskie: Loads and loads of Lzherusskie.
Mnogo Nukes: A Tu-16 "Badger", a "Moskva" class helicopter carrier.
No Plans, No Prototype, No Backup: Averted - Gant is chased by the second prototype.
Shell-Shocked Veteran: Gant, in spades. He's afflicted with PTSD throughout the movie, based on his experiences in Vietnam.
Shown Their Work: Alot of the Firefox flying scenes are laughable by today's computer-generated standards, but the dogfight was excellent. Specifically, Gant is forced to whipstall the Firefox to avoid a pair of missiles, triggering a PTSD episode. The other pilot escorts him down, but does not deliver the fatal blow (see I Owe You My Life above). He recovers from the stall by deploying his landing gear, adding drag and slowing him down, and allowing him to pull up.
Skilled but Naive: Gant's an ace Vietnam-era pilot but has no clue about playing spy games. As a result, he and The Mole leave a trail of bodies behind them.
Soviet Superscience: If not the Trope Maker, certainly a famous example.
Super Prototype
Translation Convention
Underestimating Badassery: For a while, the prototype pilot dogfights Gant by refusing to give him a clear shot for his aerial mines, but then assumes Gant doesn't know to use them and switches to conventional dogfight tactics. At the end of the dogfight, Gant finally remembers how to fire an aerial mine and destroys the second prototype.