BBC News - Jonathan Josephs
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.
