French and British investigators will explain today why they have withdrawn the airworthiness certificate for Concorde. If what they say is as serious as the withdrawal of the certificate suggests, it is difficult to imagine that the sleek supersonic jet, the pride of Britain and France for nearly 30 years, will ever fly again.
British Airways' announcement yesterday that it was following Air France and grounding its Concorde fleet is a poignant moment. Last month's crash of an Air France Concorde into a hotel on the outskirts of Paris, killing 113 people, was a huge shock.
But when BA, after checking its Concordes, declared they were safe to fly, it appeared the Paris tragedy might be an aberration, an unusual and tragic series of events that were unlikely to be repeated on any other Concorde flight.
In 24 years of commercial operations Concorde, unlike most other commercial aircraft, had never before had an accident.
It now appears, however, that French and British accident investigators have discovered a more serious flaw in Concorde that makes flying unsafe. If so, the grounding of the aircraft will mark the end of an adventure filled with pride, ambition and technical ingenuity that is unlikely to be repeated during the lifetime of those who were fortunate enough to witness it.
No one could encounter Concorde without a sense of wonder. Passengers walking through London's Heathrow Airport on the way to their humdrum Boeing and Airbus flights would stop and gaze silently if they saw it standing on the tarmac. Flying on it brought out the wide-eyed child in even the most jaded travellers.
The sense of anticipation before take-off, the excitement as the aircraft breached the sound barrier, the purple light outside as Concorde soared to the edge of space all lingered long after the flight was over.
Yet Concorde was an economic nonsense. The French and British governments which paid for its development never saw a return on their investment.
The project was conceived during the 1960s, when governments were prepared to spend large sums in the interest of national prestige and the excitement of taking humankind farther than it had been before. It is no coincidence that Concorde was built at the same time that the US was putting a man on the moon, another economically nonsensical mission that still thrills anyone old enough to remember it.
If there is a supersonic future, it will probably be in small corporate jets. This would restrict high-speed flight to an even wealthier group of travellers than the chief executives and rock stars who have filled Concorde's seats. A new large supersonic passenger jet, if it ever happens, is decades away.
There is another notion that will disappear if Concorde is grounded permanently: that air travel can be more than a dreary chore. In airports today sweaty, ill-tempered holidaymakers are straining to hear announcements about their long-delayed flights.
While aircraft might get bigger, and their engines quieter, the technology and experience of flying are unlikely to change much. The passengers will still be uncomfortable. Aircraft will still fly at less than the speed of sound.
We have become used to thinking that technology will continue its relentless advance, that television pictures will become clearer, computers faster, and mobile phones more sophisticated.
Air travel will be different. The 1970s produced an aircraft that, in speed and glamour, exceeds anything flying today and for the foreseeable future. If Concorde remains on the ground permanently, air travel will take a step backwards.
And whatever technological gadgetry future generations baffle us with, those of us who have lived in the age of the extraordinary AngloFrench flying machine will be able to tell our grandchildren: your new toys are all well and good, but we had Concorde.