The British Airways Concorde fleet was officially grounded yesterday after British and French air accident investigators confirmed that a single burst tyre was the "primary cause" of the Air France Concorde disaster which killed 113 people last month.
As speculation mounted about whether the Concorde fleet would ever fly again, the Civil Aviation Authority (CAA) acted on the advice of the Air Accident Investigation Branch (AAIB) of the Department of Transport and its French counterpart, the Bureau Enquetes Accidents (BEA), and suspended the fleet's certificates of airworthiness.
The certificates have been withdrawn until safety modifications on the seven-strong fleet to remove the risks associated with tyre bursts have been satisfactorily completed.
However, the AAIB has said that safety modifications could take "months rather than weeks" to complete and until then the British Airways Concorde fleet will remain on the ground at Heathrow airport.
The AAIB and the BEA believe the Paris crash was caused by the shredding of the number-two tyre on the left main landing gear, possibly caused by a piece of metal on the runway at Charles de Gaulle airport. The investigators said the latest evidence pointed to tyre debris causing a major rupture of at least one of the fuel tanks. This led to an intense fire, failure of the engines and then the crash less than 1 minute 30 seconds after the tyre blow-out.
British Airways grounded its Concorde fleet on Tuesday ahead of the CAA's decision and it has now cancelled all Concorde flights until early September while the safety modifications are carried out. British Airways' director of customer services and operations, Mr Mike Street, said the airline would be working closely with the British and French regulators and manufacturers to enable Concorde to fly again.
"We will only resume Concorde operations when we and the airworthiness authorities are completely satisfied that all necessary safety measures have been taken in the light of all the latest information," Mr Street said.
The British airline pilots' union, Balpa, said it had "serious doubts" about the decision to ground the fleet, saying British Airways had made safety modifications to Concorde that had not been carried out by Air France.
At a press conference in London, the CAA chairman, Sir Malcolm Field, confirmed the certificate of airworthiness had been withdrawn after the "quite unique" discovery by the Anglo-French air accident investigators.
Sir Malcolm said a burst tyre alone should never be enough to bring down a public transport aircraft. "At this stage of the inquiry what is uniquely different in this case is that tyre debris alone is thought to have led to this catastrophic accident, which has persuaded us to accept the recommendation from the investigation team," he said.
Sir Malcolm insisted that the CAA had acted "in a responsible, prudent way" in allowing the British Airways Concorde fleet to fly again within 24 hours of the Paris crash: "We looked very carefully at what happened as much as we could at the time of the accident, and reached a conclusion there was no justification to revoke its airworthiness certificate straightaway."
The AAIB's chief inspector, Mr Ken Smart, said aviation experience had shown that tyre damage during taxiing, take-off or landing was not an unlikely event on Concorde, but that it had never before led to a fuel-fed fire.
"The July 25th accident has thus shown that the destruction of a tyre - a simple event which cannot be asserted not to recur - has had catastrophic consequences in a very short time-scale without the crew being able to recover from this situation," Mr Smart said.