The airlines warned the new C-Band 5G service set to begins on Wednesday could render a significant number of widebody aircraft unusable, "could potentially strand tens of thousands of Americans overseas" and cause "chaos" for US flights.
5G has put the airlines against the US telcos who have invested rather a lot in 5G and are used to getting their way.

The chief executives of American Airlines, Delta Air Lines, United Airlines , Southwest Airlines and others have warned that 5G interference could affect sensitive aeroplane instruments such as altimeters and significantly hamper low-visibility operations.

"This means that on a day like yesterday, more than 1,100 flights and 100,000 passengers would be subjected to cancellations, diversions or delays," the letter cautioned. "To be blunt, the nation’s commerce will grind to a halt."

Airlines were considering whether to begin cancelling some international flights that are scheduled to arrive in the United States on Wednesday.

Boeing said that with the proposed restrictions at selected airports, the transportation industry is preparing for some service disruption.

“We are optimistic that we can work across industries and with government to finalize solutions that safely mitigate as many schedule impacts as possible," the plane maker said.

The letter went to White House National Economic Council director Brian Deese, Transportation Secretary Pete Buttigieg, FAA Administrator Steve Dickson and Federal Communications Commission (FCC) Chairwoman Jessica Rosenworcel.