The 10 biggest US airlines have warned that the impending switch-on of 5G mobile phone services will cause 'major disruption' to flights.

They said the start of Verizon and AT&T 5G mobile phone services, planned for Wednesday, would cause a "completely avoidable economic calamity".

Airlines fear C-band 5G signals will disrupt planes' navigation systems, particularly those used in bad weather.

The warning was issued in a letter sent to US aviation authorities.

The chief executives of American Airlines, Delta Air Lines and United Airlines were joined by others in saying: "Immediate intervention is needed to avoid significant operational disruption to air passengers, shippers, supply chain and delivery of needed medical supplies", including vaccine distribution.

The BBC has seen the letter outlining their urgent concerns. It was sent to Transportation Secretary Pete Buttigieg, as well as the head of the Federal Aviation Administration (FAA), the chair of the Federal Communications Commission and the director of the National Economic Council.

The BBC understands that negotiations are continuing at the highest levels of the US government about what has been described as a "very fluid situation".

BBC Story - https://www.bbc.co.uk/news/business-60036831

Verizon and AT&T first refused to change their plans - https://www.theverge.com/2022/1/2/22863964/faa-fcc-verizon-att-c-band-5g-airports-proposal-rejected

Following a court case where they were ordered to stop or delay the implementations, they agreed that Cell sites near major airports would not upgrade to 5G on C-band frequencies and some other changes would be delayed - https://www.theverge.com/2022/1/3/22866098/faa-dot-verizon-fcc-att-5g-c-band-delay-airplane-safety

FAA Statement - https://www.faa.gov/newsroom/faa-statements-5g