For British Airways and Air France, the two Concorde operators who announced Thursday they would ground their fleets for good by the end of October, the aircraft has never been a huge money-spinner during its 27 years of service.

This is despite even the good times of the 1980s and 1990s, when investment bankers, pop stars and wealthy jet-setters were willing to pay dearly for a ticket to the last word in luxury air travel.

The plane also proved deeply costly for the British and French governments, who developed Concorde in the mid-1960s, notwithstanding its widely-considered status as one of the great technological achievements of the 20th century.

Concorde's dubious profitability was underlined by the fact that only BA and Air France -- at the time both state-run -- opted to buy the hugely expensive aircraft.

In all, 13 Concorde aircraft went into commercial service, seven to BA and six to Air France, and neither airline has given a full breakdown of the costs and revenue from their Concorde fleets.

Air France said it would avert an operating loss of 30 to 50 million euros per year generated by Concorde by withdrawing its fleet from service.

"Certainly during the peak times across the North Atlantic when there was an awful lot of traffic flow amongst investment bankers and when world economies were in better shape, the impression at least was that Concorde was reasonably profitable," said Tim Coombs, consultant at Aviation Economics.

But the gas-guzzling jet entered commercial service in 1976, at the height of the fuel crisis of the time.

Periods of economic recession, the 1991 Gulf War and the crash of an Air France Concorde on take from Charles de Gaulle airport in July 2000 in which 113 people were killed further clipped the wings of the supersonic pioneer.

The September 11, 2001 terrorist skyjackings in the United States dealt yet another blow to confidence in air travel, especially premium trans-Atlantic flights, the mainstay of Concorde's business.

"Concorde generally performs reasonably well but never with great profitability, (even) in the most buoyant economic circumstances," said BNP Paribas analyst Nick van den Brul.

"And now of course we have a severe downturn in the European economy, and also in the US, and that means it's hardly profitable," he added.

But profit has never been the whole story behind Concorde, which was a symbol of prestige for France and Britain and a formidable marketing weapon for its two operators.

"It was, and still is, a great thing to have in terms of publicity," said Coombs.

Whether the "old lady of the sky" will have any descendants is even less certain.

Increased demand for cheap, environmentally friendly travel was underscored by US giant Boeing's decision in December to scrap plans to develop its near-supersonic Sonic Cruiser in favour of a more conventional fuel-efficient middle market jet.

Coombs said that if producers could produce a supersonic plane that met economic and environmental needs then a descendant to Concorde could emerge.

Concorde flies much higher than normal jets and the nitrogen oxide emitted from its engines breaks down ozone.

"Time is also a factor for everybody, and you're willing to pay a bit of a premium to take three hours to get to New York rather than six.

"I think as technology moves on, then I wouldn't be surprised (to see another supersonic plane), but not over the next 10 or 15 or 20 years."

SPACE.WIRE