Flybe has cancelled flights from Aberdeen and Inverness - just months after launching them.
In a surprise announcement, the airline said flights from Aberdeen to Belfast City Airport and Birmingham announced in the spring will not operate for the rest of the summer season.
Its service connecting the Inverness with Belfast City has been also been cancelled.
In total, it has grounded some 700 Scottish flights until October, blaming late delivery of aircraft.
“Every attempt has been made to contact those affected, and we will do everything we can to re-accommodate our customers on the next available Flybe flight or, if this is not possible, provide a full refund," a spokesman said.
“We understand the disappointment and frustrations these cancellations will cause and sincerely apologise to those customers who have been affected.”
In a letter to passengers, airline chief executive Dave Pflieger wrote: “The two aircraft leasing companies who were contracted to provide our additional airplanes have now told us that they will be unable to fulfil their commitments until after the summer.
“We were able to find and rent aircraft from two separate airlines in Greece and Spain, but those planes are not enough, and the lack of additional aircraft needed for new flying means we need to adjust our future flight schedule.
"We will still introduce more flights later this year – after we receive our delayed aircraft.
“This is not a decision that I have taken lightly, and as you would expect we are in daily conversations with all involved to see if anything might change that would allow us to resume our original plans at an earlier date.”
Flybe collapsed in 2020, but was relaunched in March under new owner Thyme Opco, which is linked to US hedge fund Cyrus Capital.