Everyone remembers the Concorde. Almost nobody remembers that by 1975, Aérospatiale and the British Aircraft Corporation had already designed its replacement — the Concorde B — and were within months of cutting metal when the program was quietly strangled in the crib.

The original Concorde, which entered commercial service on 21 January 1976, was a compromise aircraft. Its Olympus 593 engines needed afterburners to break the sound barrier, burning roughly 25% more fuel than cruise required and generating the notorious takeoff noise that got it banned from most American airports. Its range of 3,900 nautical miles left it stranded on Pacific routes. Its cabin held only 100 passengers because the fuselage had been frozen in 1965 to hit the delivery timeline.

The Concorde B fixed all of it. The design was frozen in 1975 by a joint Aérospatiale/BAC team led by Lucien Servanty's successors at Toulouse. The changes were not exotic:

• Olympus 593 Mk 622 engines — a redesigned combustor and larger low-pressure compressor that eliminated the afterburner entirely. Rolls-Royce and SNECMA had run the new burner cans on test stands in 1974 and hit the target: dry supersonic cruise at Mach 2.04.
• Extended wing leading edges with a small droop and a subtle increase in span. This raised lift-to-drag at cruise from 7.5 to about 8.1 — a 15% range improvement on paper, verified in ONERA wind tunnel runs at Modane.
• Higher fuel capacity in reshaped wing tanks, pushing range to roughly 4,500 nautical miles — enough for New York–Los Angeles nonstop, or Paris–Tokyo with one stop instead of two.
• Quieter takeoff — the non-afterburning departure would have cut sideline noise by an estimated 8 EPNdB, potentially opening JFK, LAX, and Sydney.

Development cost was estimated at £250 million — trivial compared to the £1.3 billion already sunk into the original. British Airways and Air France had provisionally ordered 16 airframes between them. First flight was projected for 1980.

Then, on 4 February 1976 — two weeks after Concorde's commercial debut — the British government withdrew funding. The French followed within months. The stated reason was the 1973 oil shock and pessimistic sales forecasts. The real reason was that Boeing had killed the 2707 SST in 1971, and without an American competitor there was no political prize left to win. The B was cancelled before the A had even completed its first year of revenue service.

Why now? Every technical problem the B was solving has since been solved in fragments: variable-cycle engines (GE's XA100), advanced CFD-shaped wings, sonic-boom-shaping fuselages (NASA's X-59), and modern composite fuel tanks. Boom Supersonic's Overture is essentially reinventing the Concorde B airframe with 50-year-newer materials and 40% less fuel burn per seat. The Rolls-Royce archive in Derby still holds the Mk 622 combustor drawings. The ONERA wind tunnel data still exists. A modern reboot would not be a research project — it would be an engineering exercise on a design that was 90% complete when it was shelved.

We spent 27 years flying the compromise aircraft and zero years flying the one that fixed it.