Flights across the Atlantic from the US, Canada and Mexico appeared worst-hit, with the Heathrow arrivals board showing almost all inbound planes delayed by several hours.
BA said a ‘small number’ of flights were affected, however dozens of passengers from airports between Cancun in Mexico and Chicago were complaining they were stuck on the ground and receiving little information from staff.
Thousands of British Airways passengers have been stranded in the United States after a flight management computer system fell down
One passenger, due to fly to London from Los Angeles, told MailOnline: ‘The woman I just spoke to said the flight-plan generator had crashed, it seemingly means pilots cannot get journey details and are left stranded.
‘We should have taken off hours ago and there’s no sign of us leaving. People are saying they have missed their connections already. It’s chaos.’
BA flights to Gatwick from destinations including St Kitts, Orlando and Bermuda were also running hours late early today.
It was unclear whether planes would be able to depart Hetahrow when the airport starts up on Thursday morning.
British Airways has been tweeting passengers to update them on the cause of the delay
Some passengers complained about the lack of information from the airline
Liz Yates, from London who is due to on the flight from Orlando to Gatwick told The Mirror: ‘The pilot said they don’t want us to board until they have a flight plan and because all the computers at Gatwick have gone down.
‘He came and made the announcement personally because they were mid attempting to board people in wheelchairs when they got the word.
‘They have to make some sort of arrangement with the Civil Aviation Authority.’
According to BA: ‘Our teams are working hard to fix a technical issue causing delays to a small number of flights this evening.
‘We apologise to customers affected and we’re assisting them with alternative arrangements.’