British Airways flight 223 from London Heathrow to Washington has been cancelled and delayed several times since the US raised its terror alert to high over the Christmas period.
US officials fear BA and Air France flights to the US could be targeted
BBC News Online details the groundings and delays caused by security fears.
31 December 2003: Flight BA 223 is held for security searches for three hours after landing at Washington's Dulles airport.
1 January 2004: The flight from Heathrow is cancelled because a terrorist suspect known to US authorities was believed to be trying to board it.
2 January: Flight BA 223 is grounded for the second day running because of the US intelligence.
The suspect was thought to be attempting to hijack the aircraft and crash it into a target in Washington, but he did not turn up at the airport, said the source.
2 January: BA cancels a flight to Saudi Arabia later the same day.
3 January: Flight BA 223 to Washington DC finally takes off after a further three hour and 20 minute delay, with all 268 passengers searched and taken on board one by one as armed police and sniffer dog teams stood by.
4 January: The flight is again delayed for three hours because of the stringent security measure.
5 January: The flight is delayed by three hours.
6 January: Flight BA 223 is delayed for two hours as the captain waits for clearance from the US.
7 January: A fifth consecutive delay, this time of one hour and 45 minutes, comes after French authorities announce they were hunting an al-Qaeda suspect who had booked on an Air France flight to the US on Christmas Eve but failed to turn up.
31 January: BA announces the cancellation of flights 223, as well as return flights 222 from Washington, on 1 February and 2 February. A BA flight to Miami on 1 February is also grounded.
Air France cancels two flights from Paris to Washington due to leave on 1 February and 2 February.
US officials say fresh intelligence shows BA and Air France flights to the US could be targeted by terrorists.
12 February: BA cancels flight 223, on February 15, as well as flight 263 to Riyadh, Saudi Arabia, on February 16, because of further terror alerts.