Bad weather and air traffic control restrictions have been blamed for two days of flight cancellations affecting an estimated 10,000 passengers.
More than 50 British Airways flights to and from Heathrow were affected on Sunday and a further 31 on Monday.
EasyJet was among airlines forced to cancel flights at Gatwick, with the budget carrier grounding 34 on Sunday and at least nine yesterday, according to reports.
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Two BA aircraft were reported to have been taken out of service for safety checks after they were stuck by lightening on Sunday.
A BA spokesperson said on Monday: “Due to air traffic control restrictions and adverse weather, like other airlines we’ve had to make a small number of alternations to our schedule.
“We know this will be frustrating for our customers and or teams are working really hard to get them on to alternative flights as soon as possible.”
EasyJet confirmed that it operated around 1,800 flights on both days but some flights on Sunday evening and Monday morning were disrupted due to the knock-on impact of adverse weather and air traffic control delays.