Airlines have canceled over 9,000 flights across the U.S. since the Federal Aviation Administration ordered flight cuts late last week. The cuts aim to ease demands on short-staffed control towers during the federal government shutdown. On Tuesday, another 1,200 flights were canceled as the FAA increased its target for reducing flights at major airports. Flights are expected to remain disrupted even as the shutdown nears an end, and cancellations are unlikely to ease right away. The pace of airline ticket sales for Thanksgiving travel has slowed as more travelers have reconsidered whether to fly amid all the delays and cancellations.

Transportation Secretary Sean Duffy predicted Tuesday that there could be chaos in the skies next week if the government shutdown drags on and air traffic controllers miss a second paycheck. The FAA slows down or even stops flights temporarily anytime it is short on controllers or if there is an equipment problem. There have already been numerous delays at airports across the country — sometimes hours long — during the shutdown. Duffy warned that the situation will only get worse the longer the shutdown continues and the financial pressure continues to grow on people who are forced to work without pay. FAA employees already missed one paycheck on Oct. 28. Their next payday is scheduled for next Tuesday.

Continued staffing shortages in air traffic control facilities are causing delays at airports as the government shutdown nears the one-month mark. Controllers have been working without pay since the shutdown began on Oct. 1, and Transportation Secretary Sean Duffy has been warning that travelers will see more flights delayed or canceled the longer they go without a paycheck. The Federal Aviation Administration reported staffing-related delays on Friday at airports in Boston, Nashville, Houston, Dallas, and Newark, New Jersey. Most controllers are continuing to work mandatory overtime six days a week during the shutdown. Duffy says that leaves little time for a side job to help cover bills, mortgage and other expenses unless controllers call out.

Air traffic controllers are missing another paycheck due to the ongoing government shutdown, raising concerns about financial stress affecting their work. A number of isolated flight delays have been reported since the shutdown began as more controllers call out sick. The Federal Aviation Administration was already short on staff before the shutdown. Transportation Secretary Sean Duffy and the National Air Traffic Controllers Association President Nick Daniels emphasize the pressure on controllers. Some are taking second jobs to make ends meet. The shutdown is also hindering efforts to reduce the shortage of controllers. Though pressure is mounting on Congress, Democrats and Republicans have shown little sign of being able to reach a deal to fund the government.