Hundreds of U.S. air traffic controllers have taken second jobs after missing their first full paychecks due to the government shutdown, intensifying strain on an already stretched aviation safety system, a union official said. Air traffic controllers and trainees are taking side hustles like waiting tables, delivering food for DoorDash, driving for Uber, grocery shopping for Instacart and signing up as weekend tutors to make ends meet as the shutdown enters its 28th day.

Some more context: https://en.wikipedia.org/wiki/Air_traffic_controller

In the US the Federal Aviation Administration (FAA) regulates the hours that an air traffic controller may work: controllers may not work more than 10 straight hours during a shift, which includes required breaks, and must have 9 hours of rest before their next shift.