The Federal Aviation Administration (FAA) on Friday flagged severe air traffic control staffing shortages, forcing delays at six major airports, including Atlanta, San Francisco, Washington, and Newark. Staffing triggers are now active at 10 locations nationwide.
The agency has also mandated US airlines to cancel 4 per cent of flights at 40 major airports to maintain air traffic safety amid the record-long government shutdown.
The cuts, effective from 6 a.m. ET (1100 GMT), include around 700 flights from American Airlines, Delta Air Lines, Southwest Airlines, and United Airlines.
If the shutdown continues, reductions will rise to 6 per cent on Tuesday and hit 10 per cent by November 14. International flights remain unaffected.
American Airlines CEO Robert Isom said, "This level of cancellation is going to grow over time and that's something that is going to be problematic." He added that the initial cuts are not expected to significantly disrupt customers.
United Airlines said half of its affected passengers were rebooked within four hours of their original departure. Airlines are expected to operate fewer cuts on Saturday, a lighter travel day.
The FAA released the final list of affected airports at 7:30 p.m. ET Thursday, less than 12 hours before the cuts took effect, rejecting most airline concerns after the draft order. Staffing shortages continue to ripple across the system.
FAA Administrator Bryan Bedford recently said 20-40 per cent of controllers are not showing up for work on any given day.
During the 38-day shutdown, 13,000 air traffic controllers and 50,000 security screeners have been forced to work without pay.
On Friday, the FAA implemented ground delay programs at Austin and Reagan Washington National airports and restricted space launches.
The agency also warned it could reject cuts if they disproportionately affect certain communities and may reduce up to 10% of general aviation flights at busy airports if staffing problems persist.
Airlines for America (A4A), the trade association for major US carriers, wrote on X: "The FAA has ordered US airlines to cut flights in order to maintain the safety and reliability of the National Airspace System (NAS). Safety is our shared top priority, and we will comply with the FAA’s order while working to mitigate disruption for travelers."