On Friday, the FAA announced that it would reduce the number of flights U.S. airlines need to cancel at these airports by half, as the nation’s aviation system begins to recover from a shortage of air traffic controllers caused by the extended government shutdown. Starting at 6 a.m. Saturday, airlines will only need to cancel 3% of their flights instead of the previously mandated 6%.

Initially, the FAA had instructed a reduction in flights at these busy airports due to safety concerns, as absences among air traffic controllers and airport tower staff increased. This situation arose because controllers were among the federal employees required to work without pay during the shutdown.

Flight cancellations reached their peak last Sunday, with nearly 3,000 flights, or about 10% of those scheduled, being canceled. This was a result of the FAA’s order, ongoing controller shortages, and adverse weather conditions in certain areas. As the week progressed, the situation began to improve with more air traffic controllers returning to work in light of potential developments in Congress to end the shutdown. This improvement led the FAA to halt plans for further flight reductions.

The decision to roll back restrictions follows an improvement in staffing levels after the 43-day government shutdown concluded on Wednesday night. Both the FAA and the Department of Transportation stated they would continue to monitor the situation over the weekend and assess the appropriate time for a return to normal operations.

Before the FAA released its updated guidance, airlines already seemed to be anticipating a change. Despite the restrictions still in place, just 2% of flights scheduled to depart Friday from the U.S. were canceled, according to the aviation analytics firm Cirium. By Friday evening, the flight-tracking site FlightAware was showing 273 cancellations for Saturday.

The unprecedented order started with 4% cuts that later grew to 6%, leading to the cancellation of more than 11,800 flights between Nov. 7 and Friday. The FAA originally had a 10% target.

Transportation Secretary Sean Duffy has repeatedly said safety metrics must improve before the order is lifted entirely.

Duffy hasn’t shared the specific safety data that prompted the cuts, but he cited reports during the shutdown of planes getting too close in the air, more runway incursions and pilot concerns about controllers’ responses.

How long it will take for the aviation system to stabilize is unclear. The flight restrictions upended airline operations in just a matter of days. Many planes were rerouted and aren’t where they’re supposed to be. Airlines for America, the trade group of U.S. airlines, warned there could be residual effects for days.

Some experts predicted the problems could linger longer. But airline executives were optimistic that flying could quickly rebound ahead of the busy Thanksgiving travel week once the FAA order to cut flights is lifted.

In an appearance on “CBS Mornings” after the shutdown ended, Delta Air Lines CEO Ed Bastian predicted a return to normalcy “a lot faster than people think.”

“And normal for us is an incredibly safe, incredibly reliable, great experience,” he said. “Thanksgiving is going to be a great holiday period of travel.”

The nationwide shortage of controllers isn’t new, but the shutdown put a spotlight on the problem and likely made it worse. Duffy said that by the end of the shutdown, 15 to 20 controllers were retiring daily and some younger controllers were leaving the profession.