The U.S. aviation system is expected to “remain challenged this summer and beyond,” and the Federal Aviation Administration (FAA) needs more air traffic control staff, a senior United Airlines executive said on Wednesday.

Travellers are already facing a tough summer with mounting flight cancellations amid rising demand as the industry tries to rebuild staff levels after thousands of workers left during the COVID-19 pandemic.

“The reality is that there are just more flights scheduled industry-wide than the [air traffic control] staffing system can handle,” United’s chief operations officer, Jon Roitman, said in a message to staff seen by Reuters.

“Until that is resolved, we