Budget airline Ryanair cancelled another 18,000 flights on Wednesday, deepening its woes over its mismanagement of pilots' holiday schedules.
The Irish carrier, Europe's biggest by passengers carried, says 34 routes will be suspended from November to March 2018, affecting some 400,000 customers who have already booked flights.
Under the airline's slower growth plan, some 18,000 of the airline's 800,000 annual flights will be cancelled. The airline described the measure as cancelling less than one flight per day per airport across 200 airports.
Ryanair had earlier this month said it would cancel 2,100 flights through October because it "messed up" the allocation of pilots' annual leave as it shifts to a new scheduling system.
"We sincerely apologize to those customers who have been affected by last week's flight cancellations, or these sensible schedule changes announced today," CEO Michael O'Leary said in a statement.
The routes canceled include London Stansted to Edinburgh and Glasgow, Gatwick to Belfast, Newcastle to Faro, and Glasgow to Las Palmas.
Though over 99 percent of the airline's 129 million customers will not be affected, O'Leary said "we deeply regret any doubt we caused existing customers last week about Ryanair's reliability, or the risk of further cancellations."
The airline said that reducing its fleet and slowing its growth will create spare aircraft and crew in order to manage "exceptional volumes of annual leave," as it shifted to a new scheduling system.
European safety regulations that take effect Jan. 1 and require all airlines to use a regular calendar year for calculating pilot flight hours and working days. Ryanair has until now used a 12-month period beginning April 1. Critics have suggested that the system gave the airline a competitive advantage in scheduling pilots during the busy summer season because hours accumulated from January to March didn't carry over into the new scheduling year.
The company also says it has scrapped plans to bid for bankrupt Italian airline Alitalia to focus on addressing its own problems.