Flybe has cancelled dozens of flights at the last minute, citing a raft of operational reasons, including pilot shortages.
Most of the affected flights are within the UK and include departures from Newcastle, Southampton, Aberdeen, Edinburgh, Belfast City and Birmingham.
The regional airline apologised to the thousands of customers affected and said 95% of its flights are “operating as normal”.
In a statement, the company said: “Flybe sincerely apologises to all of our customers and partners affected by the current flight cancellations.”
It added: “We are doing our best to mitigate the impact of the current situation that has arisen due to a combination of factors, including seasonality, pilots’ end of leave year, Easter holidays, base restructuring and the shortage of pilots across the industry that Flybe has highlighted over recent months.”
Flybe said it had contacted all affected passengers, who have been told that they can rebook or apply for a refund.
However, some customers said they were not given adequate information.
Disgruntled passengers aired their frustrations on social media, with one writing: “We’re stuck on the plane and not moving! Should be in Belfast in 10 mins! Absolute shocker. Operational reasons aka, someone called in sick??”
CEO Christine Ourmières-Widener apologised to customers in a statement posted to Twitter.
“We would like to apologise to all impacted customers about our cancellations today,” she said.
The CEO added that the firm was “working to mitigate the factors behind cancellation”.
Another passenger said he was notified of his cancelled flight on Tuesday evening, while another said he found out through Twitter.
Consumer organisation Which? said in a statement: “Thousands of people will understandably be frustrated to have their travel plans thrown into chaos by these last-minute cancellations – and the lack of clear information provided by Flybe was completely unacceptable.
“All passengers affected by these cancellations are entitled to a full refund or to be rerouted on to another flight to their intended destination – and to over £200 compensation under European air travel rules.”
The disruption followed the launch of the airline’s summer schedule, but Flybe did not say whether this triggered the cancellations.
The airline, based in Exeter, has been beset with similar issues of late with the implementation of the new route. Customers on Monday were left with a six-hour journey from Newquay to Heathrow, after their flight was grounded.
Cornwall Airport said the flight was cancelled because of an aircraft technical issue.
Last year, Flybe was bought for £2.8 million by the Connect Airways consortium, which includes Virgin Atlantic.