In September, Ryanair's chief executive Michael O'Leary told The Sunday Times that passengers should expect "dramatically higher" airfares when planning their European summer trips.
O'Leary said the price hike was likely due to a combination of a surge in demand for holidays and the reduction in flights, fleets and, in some cases, entire airlines.
"There is going to be about 20 per cent less short-haul capacity in Europe in 2022 with a dramatic recovery in demand," said O'Leary.
Spohr said airlines also had to take pandemic-related costs into account.
"It's possible that Lufthansa will eventually have a $10 billion bill for the whole Covid crisis. That's what it cost us. Similar numbers to our competitors. So we're all going to have to be more disciplined."
While cheap flights could still be out there, Jamie Baker, a JP Morgan airline analyst, told CNBC they would no longer fall into consumers' laps.
"Discounted fares increasingly require a hunt, and for many consumers that have been locked up for a year, they're probably not up to the effort," he said in March.