Clearance for Concorde to resume passenger flights was today put back until at least next week.
Anglo-French air regulators had been expected to issue an airworthiness certificate that would have allowed British Airways and Air France to restart fare-paying flights of the supersonic aircraft.
But the regulators said today they wanted the plane's manufacturer to supply more details of the modification work being done to prevent any repeat of last year's Air France Concorde crash in Paris that claimed 113 lives.
The delay means that BA is almost certain to miss out on any chance of starting services in September, with an October date looking much more likely now. Air France is expected to start services shortly after.
The airworthiness directive will eventually be issued to BA by the Civil Aviation Authority and to Air France by the French civil aviation authority, the DGAC.
The CAA and the DGAC will then individually return to each Concorde its permission-to-fly certificate following the planes' grounding last summer after the Paris crash that killed all 109 passengers and crew on board as well as four people on the ground.
PA