French investigators have said that an inspection of the runway used by the Concorde that crashed near Paris in July had been postponed because of a fire drill.

The BEA released photos of the burst tyre and the metal strip supposedly behind the gash

A preliminary report on the crash in which 113 people died, said that a metal strip found on the runway could have gashed one of the plane's tyres. This may have set off the catastrophic chain of events that led the plane to come down in a ball of flames shortly after take-off.

However officials from the French Air Accident Investigation Bureau (BEA) said the delay in the runway inspection did not necessarily have a bearing on the presence of the 43cm (17 inch) metal strip.

The New York-bound Concorde plunged into a hotel less than two minutes after taking off from Charles de Gaulle airport on 25 July, killing all 109 people on board and four people on the ground.

'Nothing abnormal'

At a news conference to present the preliminary report, BEA director Paul Arslanian said airport employees routinely inspected the runway three times per day.

Paul Arslanian said the metal strip resembled an aviation part

On the day the Concorde crashed, the runway was inspected at 0430 (0230 GMT), and a partial inspection carried out at 1430 because a plane was believed to have collided with a bird.

A second full inspection at 1500 was postponed because of a fire practice which started at 1435. The Concorde took off at 1643.

The report shows, therefore, that the runway was not fully inspected for more than 12 hours before the doomed plane took off.

However airport authority spokesman Didier Hamon said it was usual for Charles de Gaulle airport to carry out its three inspections a day at "relatively flexible" times.

"If anything wrong would have existed, it would have been noticed immediately," he said.

"We do believe that everything was done that day as it is normal to do. On that day, nothing abnormal, nothing exceptional was reported to the airport authority."

Grounded

Mr Arslanian cautioned against drawing hasty conclusions.

"We need to understand what was done during the fire drill," he said.

Relatives of the dead have visited the crash site

The BEA director said the metal strip thought to have burst one of the plane's tyres looked "very like an aviation part", although investigators had yet to establish how it had ended up on the runway.

Chris Yates, security editor for Jane's Aviation, said an airport such as Charles de Gaulle would be required to check for runway debris several times a day.

He said: "The French BEA's admittance that these basic safety procedures were not adhered to may have contributed to the crash."

The BEA's preliminary report into the fatal crash, released on Thursday night, stresses that it was the destruction of a forward tyre on the plane's left landing gear - probably torn by the metal strip - that set of a chain of events that brought the plane down.

British and French air safety authorities suspended the plane's airworthiness certificates in August.

The two nations have said the 12 remaining Concordes will remain grounded until the risk stemming from tyre blowouts is addressed.

Crew unaware

Too late... no time

Pilot Christian Marty

The report also contained a chilling transcript of the conversation in the plane's cockpit, which shows the crew were unaware of the engine fire which was to bring the plane down until alerted by the control tower.

The jet tried to gain speed for an emergency landing, but pilot Christian Marty was heard to say: "Too late... no time."

As the crew apparently tried to steer the plane towards the nearby Le Bourget airport, the final words from the plane came from the co-pilot: "Negative, we're trying Le Bourg...".

Communication between the control tower and the plane was then lost.

At 1645, the control tower announced: "The Concorde has crashed near Le Bourget..."

A minute later it issued this general message: "For all planes listening, I'll get back to you in a minute. We're going to pull ourselves together and restart take-offs."