The shutdown in Washington has caused grounded or delayed flights in airports across the country.
Air travel was crippled across the U.S. this weekend. Blame is on staffing shortages.
TSA agents and air traffic controllers are still on the job, but they're not being paid. Controllers will miss their first full paycheck on Tuesday.
"They get a notice of what they're going to be paid on Tuesday, and they got a big fat zero, no paycheck is coming on Tuesday, and so I've been out talking to our air traffic controllers. And you can see the stress," Transportation Secretary Sean Duffy told Fox News Channel's "Sunday Morning Futures."
The FAA issued 22 "staffing triggers" on Saturday — a designation of understaffing of air traffic controllers.
More than 8,000 U.S. flights were delayed on Sunday and nearly 200 more were cancelled, according to tracking site FlightAware.
Duffy says that trend could continue, with the potential for more air traffic controllers to call in sick in order to work second jobs to make ends meet.
"You're going to see more staffing shortages in towers which means more delays, more cancellations," Duffy said.
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Many travelers are growing frustrated, but say they're sympathetic to air traffic controllers' dilemma.
"Well, I'm thinking if I weren't getting paid, I would be very angry. That would make it difficult to do my job. I'm hoping someone is taking care of them," one traveler said.
The union that represents air traffic controllers says it doesn't support any sort of organized work stoppage — but acknowledges that its workers are growing more stressed.
"So, air traffic controllers, we didn't start a shutdown. We don't end the shutdown. Our elected officials do, and our message is simple: End the shutdown today," said Nick Daniels, president of the National Air Traffic Controllers Association.
