The United States has lifted an hours-long ground stop at the nation's airports, with top officials telling reporters at the White House that the disruption was not due to a cyberattack or a sweeping Microsoft outage.
Transportation Secretary Sean Duffy said late on Friday that US airspace was now "opened up," and blamed "old hardware" for the travel chaos.
Homeland Security Secretary Markwayne Mullin told reporters there was "no cyberattack" and "no connection between this and Microsoft."
Duffy said that he had spoken with Trump about the aviation ground stop and that the president was fully engaged on the issue.
He said a legacy air traffic control communications system became overloaded and began issuing faulty data prompting a nationwide ground stop that led to more than 10,000 cancelled and delayed flights.
"Our switches, our routers, actually got overloaded with data... They started to give us inconsistency in the data ...and because of that, we shut the system down," Duffy said at a White House briefing, adding it had intermittent communication and intermittent radar.
Duffy seeks billions to overhaul systems
The transportation secretary, meanwhile, sought $50 billion to improve America’s air traffic control system.
"Let’s not do a patchwork fix to a system that’s critical for every single family," Duffy said, adding President Trump has asked Congress for $30 billion.
"I want $50 billion," Duffy said.
Last year, the US Congress approved $12.5 billion over five years to modernise air traffic control, with a further $30 billion now requested, Reuters reported.
Duffy highlighted past air traffic control problems, citing outages in Newark that disrupted flight operations.
"This is a continual problem that we have, and it should be fixed," Duffy added.
