In brief: The CEOs of major passenger and cargo airlines have warned of catastrophic disruption to flights when the new 5G spectrum is deployed tomorrow (January 19). The chief executives fear that "tens of thousands of Americans" could even be stranded abroad as a result of AT&T and Verizon switching on their new C-Band 5G networks.

Reuters reports that a letter signed by the CEOs was sent to Transportation Secretary Pete Buttigieg, Federal Communications Commission (FCC) Chairwoman Jessica Rosenworcel, FAA Administrator Steve Dickson, and White House National Economic Council director Brian Deese.

"Unless our major hubs are cleared to fly, the vast majority of the traveling and shipping public will essentially be grounded," wrote the chief executives.

The concerns stem from the C-band airwaves interfering with sensitive equipment on some aircraft. This includes the altimeter, which is essential when landing in low visibility.

"Airplane manufacturers have informed us that there are huge swaths of the operating fleet that may need to be indefinitely grounded" because of the new 5G deployments, the airlines warn in the letter. "Immediate intervention is needed to avoid significant operational disruption to air passengers, shippers, supply chain and delivery of needed medical supplies."

AT&T and Verizon already delayed the rollout of their C-Band 5G from December to this week over aircraft interference concerns.

United says it faces "significant restrictions on 787s, 777s, 737s and regional aircraft in major cities like Houston, Newark, Los Angeles, San Francisco and Chicago."

The airlines aren't asking for the rollout to be abandoned; they just don't want 5G implemented within 2 miles of runways at some key airports. This distance could be reduced following further analysis by the FAA.

On January 3, AT&T and Verizon agreed to place buffer zones around 50 airports for six months to reduce interference risks, but these zones are apparently smaller than the 2 miles the airlines are requesting. The carriers argue that C-Band 5G has already been deployed in about 40 other countries without aviation interference issues.