The highest a jet has ever flown under its own power is not an American record, and it is nearly half a century old. On August 31, 1977, Soviet test pilot Alexandr Fedotov zoom-climbed a MiG-25 to 37,650 metres — 123,523 feet — and no air-breathing aircraft has beaten it since.

That is more than 23 miles up, well into the black of near-space, where the sky overhead turns dark and the curve of the Earth is unmistakable. The Foxbat got there not by cruising but by trading raw speed for height in a ballistic lunge toward the edge of the atmosphere.

How You Fly to the Edge of Space

No jet can sustain level flight at 37 kilometres — the air is far too thin for wings or engines to work. So Fedotov did what record-setters do: he accelerated to high supersonic speed in the thick lower atmosphere, then pulled up and let momentum carry the aircraft upward like a thrown stone. Near the top, the engines were starved of air and the controls went mushy, the jet coasting on inertia alone before nosing over and falling back into breathable sky.

The Plane the West Feared

The MiG-25 was built as a high-speed, high-altitude interceptor, and Western intelligence badly overestimated it — until a defector handed one over in 1976 and revealed steel construction and vacuum-tube electronics. Yet the Foxbat’s brute performance was real, and the altitude record is its enduring proof. Fedotov, a Hero of the Soviet Union, would die in 1984 testing the MiG-25’s successor, the MiG-31. His record outlived him, and it has outlived every jet built since.

Sources: Fédération Aéronautique Internationale (FAI) record listings; National Museum of the U.S. Air Force; The Aviation Geek Club.