Simply the best in the sky: Concorde never quite took off commercially, but it is 25 this week. It deserves a successor for the 21st century, says Jonathan Glancey

CONCORDE is 25 years old. The French prototype, 001, took off from Toulouse on 2 March 1969; its British sibling blasted off from Filton a month later. Although the supersonic aircraft is nearly always referred to in the singular, 20 were built and 14 are flying in everyday service with Air France and British Airways. The French aircraft are being upgraded with superb new interiors by Andree Putman, doyenne of French designers, and the British Airways' fleet is following suit. Richard Branson, meanwhile, is keen to lease a brace of Concordes to soar profitably between London and Hong Kong.

For all its faults - it is far too noisy on take-off and landing and many consider it to be a form of ecological air-raid - Concorde remains the most beautiful and exciting of all passenger planes. Supermodels from Jean Shrimpton to Kate Moss come and go, but supersonic Concorde retains the power to turn people's heads as it did a quarter of a century ago. Its catwalks are the runways of the world. Only the most po-faced ecologist or the most visually illiterate philistine ignores the Anglo-French beauty as it struts on long hydraulic legs between crowds of penny-plain, 300- seat aeroplanes that dominate international airports.

And who can fail to thrill to an aircraft that, looking as mythically modern today as it did 25 years ago, rockets into the sky to command the heavens at 60,000ft and 1,350mph? At its cruising height, passengers look into a peerless deep-blue sky, more 'space' than 'air' and can see the curvature of the Earth below: this is the territory of Chuck Yeager - test pilot and the first man to break the sound barrier - and God.

It evokes so many images: on land, with its nose cone lowered, it resembles some giant stork or crane. From some angles it looks as if its shape has been fashioned by some Origami master. In flight it exhibits a fitness of purpose combined with an absolute beauty rivalled by only the most perfect works of art.

There will be many for whom Concorde is simply tiresome, noisy, gas-guzzling and irrelevant. Not those, of course, who still pay well over the odds (London to New York return, pounds 5,030) to sit tight in the confined cabin of the only passenger plane to rival the performance of Top Gun jet fighters. For them - movie moguls, business tycoons, Concorde buffs - Concorde is quite simply a superior form of transport to the lumbering Jumbo cruising 25,000ft below it and the way to arrive in style at Heathrow or JFK. Richard Branson understands the visceral and romantic appeal of this great aircraft: he is cocksure certain that he will make Concorde fly profitably on long-haul flights to the Pacific Rim.

Yet, for all the excitement that still surrounds it, Concorde has never quite taken off commercially. It makes money now, but not the buckets of lolly it was meant to. Although aviation engineers in France and Britain continue to toy with its successor, Concorde may yet prove to be a mechanical dodo.

When the idea of a supersonic airliner was first proposed in the mid-Fifties, the future of civil aviation was supersonic all the way. Boys' comics and adult engineering magazines were awash with illustrations of Concorde-like planes that would whizz a thousand Doris Day and Fred MacMurray lookalikes from London (hub of the universe) to Sydney within a couple of hours. Speed was the drug pushing design and engineering ever onwards and upwards: the buzz-words then were atomic, sputnik, space and supersonic. We were all going to go faster and faster and very few people seemed aware of the ecological costs of doing so.

The British and the French began working together on Concorde in 1962 (BOAC had taken its first reservation for a supersonic flight in 1960). Development took seven years and cost a whopping pounds 1.5bn. Like the Channel tunnel, Concorde always seemed a long way off, a legend before it flew. Before it reached for the sky, its development gave medical science laser-beam technology and the airlines considerable headaches as New York City debated whether or not it would accept a supersonic airliner.

There was, however, magic in the air when the aircraft finally entered commercial service in January 1976 (between London and Bahrain and Paris and Rio) after record testing and endurance trials. Here was a plane that could take off from Heathrow at 10.30 in the morning and get you to New York for breakfast. It could do the trip back to London in less than three hours if pushed (Concorde sails above most weather); it was reliable (you can just about set your watch by Concorde flights), and it has proved extremely safe - since going into service, the plane has been accident-free.

Today, the only giveaway signs of Concorde's vintage are its noise (four Rolls-Royce Olympus jets equipped with afterburners are incapable of whispering like the jets of an anonymous new Boeing) and its size (it seats just 100 passengers and looks quite delicate sitting alongside Airbuses and Jumbos) and its cockpit.

Designed and built before the day of digital instruments and 'fly-by-wire', Concorde's cockpit recalls that of the great transatlantic airliners of the Fifties: Britannias and Super- Constellations. The pilots are the best in the business and the atmosphere they create in their cramped working conditions evokes the flamboyance of Johnny Halliday, the derring- do of Dan Dare.

An antique? Yes, if you happen to like your aircraft a bit quieter and less dipsomaniacal. Not, however, in terms of performance, reliability, safety and future commercial opportunities. The present generation of Concordes will probably fly for another 15 years (they are beautifully made and lovingly maintained).

The question now is whether Concorde will ever be replaced. In 1990 Airbus Industrie announced plans for a faster and bigger (250-seat) successor. It talked of development costs of pounds 10bn and sales of 450 aircraft. Boeing and McDonnell Douglas, the American giants, were sceptical and one Wall Street analyst described the announcement as a 'death rattle from a group that can't get funding'.

The Americans also pointed out that 200 Concordes were meant to have been sold. Was this just sour grapes? The American Concorde rival came to nothing (and the Soviet 'Konkordski' prototype crashed). Even so, American aero-engineers continue to work today on a hypersonic passenger plane that will fly at five times the speed of sound. The age of speed, ostentatious progress and the spirit of Icarus has yet to die. So has Concorde.

For the foreseeable future, the major thrust of commercial aircraft development will be towards massive, quiet jet airliners that will carry ever more business people and tourists to ever more exotic locations ever more cheaply and even more safely than they do now. Yet because of their sheer volume, these globe-trotting airbuses are far more of an ecological menace in the long term than Concorde. Its noise, beauty and rarity make Concorde too easy a target for those who see this magnificent machine as flying in the face of God.

(Photograph omitted)