The United States has reopened its commercial airspace after a sweeping communications collapse triggered the longest nationwide flight grounding in a quarter-century.

Federal regulators lifted the departure halt late Friday evening, allowing commercial airliners to begin taxiing for takeoff once more. However, transportation officials and major airlines warned passengers that widespread cancellations, displaced crews, and crowded airport terminals will complicate travel well into Saturday.

The crisis began Friday afternoon when regional air traffic control centers suddenly lost telecommunications links, leaving controllers unable to route departing traffic safely.

Airspace Reopens After Historic 25-Year Stoppage

The Federal Aviation Administration initially grounded all domestic departures at 3:54 p.m. Eastern Time, citing “extraordinary circumstances and reasons for safety.”

The ground stop remained in effect for nearly four and a half hours, finally lifting at 8:15 p.m. Eastern Time. The duration made it the longest nationwide departure halt since the terrorist attacks of September 11, 2001, surpassing the brief systemwide grounding caused by a corrupted database file in January 2023.

Aviation tracking company Cirium reported that roughly 11,000 scheduled flights carrying more than 1.5 million travelers were disrupted during and immediately following the shutdown.

More than 3,000 commercial flights already in the sky when the order was issued were cleared to land safely at their destinations, while international flights bound for the United States were evaluated on a case-by-case basis.

Software Updates Overloaded Aging Air Traffic Routers

Federal officials moved quickly on Friday night to explain the root cause of the breakdown and quell public anxiety.

At a White House briefing, Homeland Security Secretary Markwayne Mullin emphasized that investigators found no evidence of a cyberattack, hostile action, or security breach.

“Everybody’s safe,” Mullin told reporters, explaining that the issue stemmed entirely from an internal technical failure rather than outside interference.

Transportation Secretary Sean Duffy later clarified that technicians were installing modern software updates into the Federal Aviation Administration's network when the new programs overloaded antiquated telecommunications equipment and routers.

“It’s an old system that went down. It went down everywhere,” Duffy said at a Friday night news conference, describing the nation's air traffic backbone as an aging, patched-together apparatus in urgent need of overhaul.

Airlines Face Cascading Delays and Crew Timeouts

Although the FAA has cleared runways for departures, restoring normal flight schedules remains a massive operational puzzle.

Airlines spent the overnight hours repositioning hundreds of aircraft that had been diverted or held at destination gates. Carriers also faced severe staffing shortages as pilots and flight attendants reached federal duty-time limits while waiting on grounded planes.

“We’ve opened up the airspace, but it’s going to be slow,” Duffy warned travelers, advising passengers not to rush to airports without confirming their flight status directly with carriers.

Major domestic carriers, including Delta Air Lines, American Airlines, United Airlines, and Southwest Airlines, issued systemwide travel waivers allowing ticketed passengers to rebook flights without change fees or fare differences.

Airport authorities at major transit hubs—including Atlanta, Chicago O'Hare, Dallas-Fort Worth, and New York JFK—reported crowded boarding areas as gate agents worked through backlogs of rescheduled travelers.

Washington Reckons With Aging Aviation Infrastructure

The Friday shutdown has reignited longstanding debates in Washington regarding the modernization of the nation’s critical civil aviation infrastructure.

For years, aviation industry groups and air traffic controllers have warned that the Federal Aviation Administration relies on legacy systems vulnerable to single-point failures. The sudden breakdown across all regional Air Route Traffic Control Centers demonstrated how fragile interconnected networks remain during routine technology updates.

Lawmakers on Capitol Hill are expected to call transportation officials and agency administrators to testify regarding why fail-safe redundancies failed to prevent a nationwide blackout.

For millions of travelers across the country, however, the immediate focus remains on Saturday’s departure boards, where airlines continue the gradual effort to rebuild their networks.