Hundreds more flights were cancelled across the US this weekend amid severe weather in Florida.
JetBlue and Spirit were among the airlines worst hit by the disruptions.
The two carriers’ cancellations totalled more than 300 on Saturday and 254 on Sunday.
JetBlue cancelled 18 per cent of its scheduled flights on Saturday and 13 per cent of departures on Sunday; Spirit cancelled 14 per cent of Saturday flights and 13 per cent of Sunday flights.
A Spirit spokesperson said poor weather and Air Traffic Control (ATC) issues in Florida on Thursday and Friday were still having a knock-on effect over the weekend, hence the widespread disruption.
Meanwhile, JetBlue president Joanna Geraghty sent a memo to staff apologising for the operational problems.
She referenced the fact that the airline hit headlines recently due to its surprise bid for a merger with Spirit.
“We had some big news at JetBlue this week, and while that has rightly been the focus of a lot of buzz, I want to assure you our #1 priority right now is the operation,'' she wrote in the email to employees.
“You have been simply incredible under very difficult circumstances, and we want to thank you for all you are doing to take care of our customers.
“We are letting you and our customers down, and that is not consistent with what we stand for.”
Geraghty said “cascading problems'' with flights in April were as a result of poor weather and ATC delays.
“We are working around the clock to address some of the most difficult operating conditions we have ever faced as a company,” she said.
Flight cancellations have also been an issue in the UK this Easter, with British Airways and easyJet axing a combined total of more than 100 services most days over the past week.
Both carriers have cited staff shortages caused by Covid as the reason for cancellations.
