Regional airline Flybe has cancelled dozens of flights on Wednesday morning for what it describes as “operational reasons”.
Five flights from Belfast City Airport and four from Birmingham are among those affected, along with departures from Southampton, Aberdeen, Edinburgh and Newcastle.
Most of the flights are within the UK.
The airline said it would like to “sincerely apologise for any inconvenience caused”.
“All customers affected have been emailed and advised they can rebook for travel on an alternative flight or apply for a full refund,” the company said in a statement.
On Monday, Flybe passengers on a new route were left with a six-hour coach journey when their aircraft was grounded.
The 18:40 service from Newquay to Heathrow could not take off on Sunday because of a “technical issue”.
Cornwall Airport Newquay said passengers were offered “rebooking for another flight or ground transport to London Heathrow”.