By David Shepardson

WASHINGTON U.S. airlines on Tuesday expressed growing frustration with Federal Aviation Administration air traffic control staffing (ATC) shortages, which have snarled flights and forced regulators to extend waivers on minimum flight requirements.

"In the short to medium term we have to reduce flights in very impacted airports because the system can't cope with the number of flights today," JetBlue Airways CEO Robin Hayes told Reuters on the sidelines of an industry conference Tuesday. "We're selling flights that we know we won't be able to operate because of ATC challenges."

Airlines have faced flight woes after a record-setting U.s. summer travel season and voluntary cut flights because of air traffic shortages. They want to add more flights to address demand.

United Airlines CEO Scott Kirby, who harshly criticized the FAA this summer, said at the conference that lagging air traffic staffing levels "was two decades in building and it is going to take years to get it addressed."

The FAA declined to comment Tuesday beyond a statement it issued in August that said it met its goal of hiring 1,500 controllers in the year ending Sept. 30. But it is still about 3,000 controllers behind staffing targets.

Hayes said if the FAA doubled controller hiring - which it cannot - "it would still take us five years to catch up."

The FAA has about 2,600 controllers in training. The Transportation Department is seeking $117 million to hire another 1,800 next year.

Citing ATC staffing issues, the FAA in August extended temporary cuts to minimum flight requirements at congested New York City-area airports and Washington National Airport through Oct. 28.

A government watchdog said in June that critical ATC facilities face significant staffing challenges, posing risks to air traffic operations.

The United States has experienced several near-miss aviation incidents this year, including some that could have been catastrophic involving apparent controller mistakes.

The FAA has 10,700 certified controllers, up slightly from 10,578 in 2022, virtually the same as 2021 and down 10% from 2012. Of the FAA's 13,300 controllers, 26% are trainees.

At several facilities, controllers are working mandatory overtime and six-day work weeks to cover shortages.

Last summer, there were 41,498 flights from New York airports in which ATC staffing was a contributing factor in delays. New York Terminal Radar Approach Control staffing was at 54%, the report said.

(Reporting by David Shepardson. Editing by Gerry Doyle)