US air travel thrown into chaos as nationwide flights grounded over 'radar instability'

Chaos was reported at airports across the United States on Friday after the Federal Aviation Administration (FAA) ordered a nationwide ground stop for departing flights following problems with radar and communications systems.

Passengers were stranded as hundreds of flights were diverted and thousands cancelled.

Officials said instability in radar systems made it unsafe to continue normal operations.

The FAA said in a statement that communications problems had affected multiple air traffic control centres and that technicians were investigating.

Transportation Secretary Sean Duffy said the disruption began at 3.36pm EST (8.36pm GMT), when radar and communications systems at facilities across the country became unstable.