The supersonic Concorde passenger jet was given the go ahead to fly again by British and French officials Wednesday, more than one year after a fiery crash killed 113 people aboard an Air France Concorde in France.

Before the jet can fly, the two airlines that fly Concorde must complete a series of safety modifications. The Civil Aviation Authority in London issued a "mandatory airworthiness directive" to British Airways Wednesday and French authorities issued a similar document to Air France.

Key modifications that must be made include stronger tires, fuel tank linings made of bulletproof Kevlar, and extra protection for critical electrical and hydraulic systems on the underside of the wings.

The focus on reinforced fuel tanks stems from last year's crash of the Air France Concorde. Investigators believe a stray strip of metal on the runway punctured one of the doomed plane's high-pressure tires, which blew a hole in a wing fuel tank and started a fire. 

Air France grounded its Concorde fleet immediately after one of its jets crashed minutes after takeoff from Paris on July 25, 2000. The dead included 100 passengers, mostly tourists from Germany, the crew of nine and four people on the ground.

British Airways kept flying Concorde between New York and London until mid-August of last year, stopping service just before the two governments withdrew the certificate permitting it to fly.

British Airways, which last year announced a $20 million remodeling of cabin interiors and Concorde lounges in New York and London, planned a series of five test flights with employees filling the seats in the fabled aircraft.

Employees were invited to enter a drawing to take one of the 100 seats in the plane to help test all aspects of operations, including ticketing, boarding and in-flight services.

Four flights will turn around in the mid-Atlantic and one will go all the way to New York, British Airways said.

British and French authorities have been determined to return the Concorde to service. The plane was a commercial failure, partly because no country would permit it to fly over land because of loud engines, and partly because the fuel-guzzling Concorde carries just 100 passengers, making it less economical than a jumbo jet. Only 20 were built, with 12 remaining in service.

But the delta-winged, needle-nosed plane conferred matchless prestige on British Airways and Air France, drawing celebrities and business people who thought their time was valuable enough to justify fares of more than $8,700 for a round trip across the Atlantic.

"There will always be a certain number of passengers for whom getting from point A to point B in the shortest period of time is important, whether it be for diplomatic or business reasons or whatever," said Chris Yates, aviation safety and security editor for Jane's Transport.

"Concorde fulfills this niche market very well."

The Concorde flies faster than any other commercial aircraft, racing between Europe and New York in under four hours. Its fastest New York to London crossing was completed in just 2 hours, 52 minutes and 59 seconds.

The Concorde cruises at 1,350 mph, or twice the speed of sound, at an altitude of 60,000 feet.

Although Boeing Co. is developing a passenger jet — the Sonic Cruiser — that would travel at close to the speed of sound, industry analysts say it's too early to know whether the concept will be a success.

The Associated Press contributed to this report.