More than half of the world’s airline pilots are no longer flying for a living, according to a worldwide survey highlighting how the Covid-19 pandemic has devastated the profession.

The Pilot Survey 2021, by aviation recruitment firm Goose and publisher FlightGlobal, showed just 43% of pilots remain in their job. The October poll covered almost 2,600 flight crew worldwide.

While vaccinations remain aviation’s great hope for a recovery, infection flareups and mutant variants of the virus have dashed prospects for a steady return of scheduled services.

The International Air Transport Association has said flying may not return to pre-pandemic levels until 2024, putting a lengthy strain on the pilot profession.

In the survey, 30% of respondents described themselves as unemployed and 17% said they were furloughed. Another 6% still work in aviation but in a non-flying role, and 4% had switched to a different industry altogether.

Of the regions represented in the survey, the U.S. was least hardest hit, with 20% of pilots unemployed. China had the largest group of furloughed pilots at 24%. In a sign of some optimism, almost three-quarters of pilots expect the industry to fully recover in one to three years.