Ryanair has said it will be forced to cut the number of summer flights it operates next year blaming further expected delays before the Boeing 737 Max is allowed to fly again.
The airline said it could be as late as December before regulators clear the aircraft to return to the skies after two fatal crashes.
It was awaiting delivery of 58 planes before next summer but it now expects to receive just over half of those.
It could also close bases as a result.
The airline said it was in talks with airports about which of its hubs could suffer cuts.
“We are starting a series of discussions with our airports to determine which of Ryanair’s underperforming or loss making bases should suffer these short term cuts and/or closures from November 2019,” the airline’s chief executive, Michael O’Leary, said in a statement.
Ryanair added that it would talk to its staff and unions about the planned closures, which it said were “directly caused” by the delays delivering the 737 Max.
The airline is now expecting to carry 157 million passengers in the year to March 2021, five million fewer than it had been planning for.
Airline analyst Chris Tarry told the BBC that the move to cut routes was “entirely predictable” after the 737 Max was grounded.
He said the plane was “unlikely, even with a following wind, to return to the skies before the end of the year”.
There’s a finite number of aircraft that Ryanair can use, he said, explaining that the airline would use those planes on the most profitable routes.
Another airline expert, John Strickland, said the grounding was likely to have an effect on the airline’s growth plans. At present Ryanair has around 455 planes but it plans to expand its fleet to roughly 600 by 2025.
“A lot of it is about limiting growth rather than cutting back,” he said.
“In the summer they would have expected to grow strongly, having additional bases and additional routes.”