The chief executives of major U.S. passenger and cargo carriers on Monday warned of an impending ¡°catastrophic¡± aviation crisis in less than 36 hours, when AT&T and Verizon are set to deploy new 5G services.

The airlines warned the new C-Band 5G service set to begin on Wednesday could render a significant number of widebody aircraft unusable, ¡°could potentially strand tens of thousands of Americans overseas¡± and cause ¡°chaos¡± for U.S. flights.

¡°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 of American Airlines, Delta Air Lines, United Airlines, Southwest Airlines and others in a letter first reported by Reuters.