WASHINGTON, D.C.: The Federal Aviation Administration on November 15 cut in half the number of flights U.S. airlines must remove from their schedules at 40 airports, as the aviation system begins to recover from the air traffic controller shortage caused by the record government shutdown.

Starting at 6 a.m. on November 15, airlines were required to cancel only three percent of flights instead of six percent, the agency said. The FAA first ordered reductions on November 7 due to safety concerns, as controller absences increased at air traffic centers and airport towers. Controllers were among the federal workers required to stay on the job without pay during the shutdown.

Cancellations peaked on November 9, with nearly 3,000 flights — about 10 percent of those scheduled — scrapped due to the FAA order, persistent staffing shortages, and bad weather. But numbers began to improve as more controllers returned to work and congressional negotiators signaled progress on a shutdown deal, leading the FAA to hold off on further cuts.

The FAA and the Department of Transportation said staffing has strengthened since the 43-day shutdown ended late on November 12. They will continue monitoring conditions through the weekend before deciding when full operations can resume.

Airlines appeared to be expecting the easing of restrictions. Even before the FAA issued its updated guidance, only two percent of U.S. departures were canceled on November 14, Cirium data showed. By that evening, FlightAware listed just 160 cancellations for the following day.

The unprecedented FAA order initially required four percent cuts, later increased to six percent, leading to more than 11,800 cancellations between November 7 and 14. Officials had initially contemplated reductions of up to 10 percent. Transportation Secretary Sean Duffy has said safety improvements are essential before the mandate can be lifted completely.

While he has not released specific safety data, Duffy pointed to reports during the shutdown of planes flying too close together, of more runway incursions, and of pilot concerns about controller performance.

How quickly the system will fully stabilize is unclear. The restrictions have disrupted airline operations, leaving many aircraft out of position. Airlines for America, the industry's leading trade group, warned that ripple effects could continue for days.

Some analysts have predicted longer delays, but airline leaders remain optimistic. Delta Air Lines CEO Ed Bastian told "CBS Mornings" that operations could bounce back "a lot faster than people think," adding that the industry expects a firm and smooth Thanksgiving travel period.

The nationwide controller shortage predates the shutdown, but the prolonged stoppage highlighted the issue and may have worsened it. Duffy said 15 to 20 controllers were retiring each day by the end of the shutdown, and some younger controllers had decided to leave the profession.