The brief
US authorities halted flights across the country after communication problems affected air traffic control, an extraordinary step that threatens to disrupt travel well beyond US borders. The Federal Aviation Administration said in an advisory notice on its website on Friday that a ground stop affects all US airports and that departing flights should remain grounded until further notice. The agency cited "extraordinary circumstances" and "reasons of safety."
US Transportation Secretary Sean Duffy said FAA technicians were investigating the issue. Homeland Security chief Markwayne Mullin later said there was no indication of a threat to the country, offering reassurance as the grounding left passengers and airlines facing widespread delays.S2
