The US Department of Transportation (DOT) has frozen mandated capacity cuts at 40 major airports at 6%, dropping the previously planned ramp-up to 10% by November 14. The decision was taken hours before the record-long US government shutdown ended on November 13, and will be kept in place until further notice.

"The 6% hold will remain in place as the Federal Aviation Administration continues to assess whether the system can gradually return to normal operations," the DOT said.

The new emergency order replaced the previous one, which imposed cuts of up to 10%. However, the regulator retained restrictions for general aviation operations at 12 airports, on visual flight rule approaches (VFR) at facilities with staffing triggers (four triggers were reported on November 12, down from a high of 81 on November 8), on commercial space launches, and on parachute operations and photo missions near facilities with staffing issues.

The 40 affected airports remain the same: Anchorage Ted Stevens, Atlanta Hartsfield Jackson, Boston, Baltimore International, Charlotte International, Cincinnati International, Dallas Love Field, Washington National, Denver International, Dallas/Fort Worth, Detroit Metropolitan, New York Newark, Fort Lauderdale International, Honolulu, Houston Hobby, Washington Dulles, Houston Intercontinental, Indianapolis International, New York JFK, Las Vegas Harry Reid, Los Angeles International, New York La Guardia, Orlando International, Chicago Midway, Memphis International, Miami International, Minneapolis St. Paul International, Oakland International, Ontario International, Chicago O'Hare, Portland International, Philadelphia International, Phoenix Sky Harbor, San Diego International, Louisville International, Seattle Tacoma International, San Francisco, Salt Lake City, Teterboro, and Tampa International.

According to Reuters, the FAA was approximately 3,500 air traffic controllers short of its targeted staffing levels, with many working mandatory overtime and six-day work weeks even before the shutdown. During the shutdown, they were required to continue working without pay as part of the essential workforce that remained in place.

“If the FAA safety team determines the trend lines are moving in the right direction, we’ll put forward a path to resume normal operations,” Transportation Secretary Sean Duffy said in a statement, without providing a timeline.

Airlines, such as Southwest Airlines, are optimistic that the capacity reduction will only last a few days following the end of the shutdown, chief operating officer Andrew Watterson told employees in a note. Delta Air Lines chief executive Ed Bastian told CNBC he thinks the aviation system will be largely back to normal by November 17.