US air travel disruptions continue into third day

US air travel disruptions persisted for the third consecutive day, with over 5,200 flights impacted as of Sunday, according to Reuters. Transportation Secretary Sean Duffy anticipated normalcy by Monday, despite airlines working to restore schedules following a systemwide ground stop. By FlightAware's data, more than 1,600 flights were canceled nationwide, and nearly 3,600 delayed on Sunday.

Duffy stated there was no evidence of a cyberattack, but the cause remained unknown. By Sunday, 27% of JetBlue's flights and 13% of American Airlines' flights were canceled, with Southwest, United Airlines, and Delta reporting cancellations of 3% to 5% of their respective flights. The Federal Aviation Administration (FAA) had implemented a nationwide ground stop on Friday, halting nearly all departures for nearly five hours – the longest such halt since the 9/11 attacks.

The issue stemmed from the installation of a router by an FAA contractor, which overloaded air traffic control systems with data, Duffy explained. The malfunctioning routers, purchased in 2001 and obsolete by 2006, were replaced, but the root cause of the problem remained unclear. President Trump endorsed Duffy's request for $50 billion to upgrade the air traffic control system, urging Congress to approve the funding in one go rather than in increments.

However, top Democrats on the House Transportation and Infrastructure Committee expressed skepticism, pointing out that about $11 billion of the approved $12.5 billion remains unspent.