FILE PHOTO: Ryanair Chief Executive Michael O'Leary attends the Europe Aviation Summit in Brussels, Belgium March 3, 2020. REUTERS/Johanna Geron/File Photo

FRANKFURT (Reuters) - Ryanair RYA.I may have to lay off 10-20% of staff in the winter season as it will operate fewer flights due to the coronavirus crisis, Chief Executive Michael O'Leary said in a newspaper interview published on Friday.

Citing an expected drop in flights by 20-30% in the winter schedule, O’Leary told German business daily Handelsblatt that fewer staff would be required.

“I think that job reductions by 10-20% in winter are almost inevitable,” he said. “Passengers will return, but it will take time.”

There could also be a second wave of worldwide infections, he said.

When lockdowns end, airports and planes will have to ensure rules on social distancing and protective gear. O’Leary has backed anti-virus measures but rejected calls for planes to fly one-third empty.