RELATED: Delta CEO Warned This Major Change Is Coming to Flying. Both AT&T and Verizon plan to roll out their new 5G networks on Jan. 19. But the heads of several major U.S. airlines just warned that the implementation of 5G service could cause “catastrophic disruption” for flights across the country, Reuters reported. Delta, America, United, and Southwest CEOs, alongside several others, sent a letter to Transportation Secretary Pete Buttigieg, Federal Communications Commission (FCC) Chairwoman Jessica Rosenworcel, Federal Aviation Administration (FAA) Administrator Steve Dickson, and White House National Economic Council director Brian Deese on Jan. 17, warning that “immediate intervention” is needed to avoid “significant operational disruption to air passengers, shippers, supply chain, and delivery of needed medical supplies.” “We are writing with urgency to request that 5G be implemented everywhere in the country except within the approximate two miles of airport runaways at affected airports,” the CEOs wrote in their letter. “This will allow 5G to be deployed while avoiding harmful impacts on the aviation industry, traveling public, supply chain, vaccine distribution, our workforce, and broader economy.” RELATED: American Is Cutting Flights From These 6 Major Cities, Starting in February. Flight experts and officials are particularly concerned about the impact that the frequencies used for 5G service, which are in a radio spectrum called the C-band, will have on a key aviation tool. The frequencies might be potentially too close to the frequencies used by a radar altimeter, an “important piece of safety equipment” especially for flight landing when visibility is limited, per the FAA.ae0fcc31ae342fd3a1346ebb1f342fcb As a safety precaution, the FAA recently released a list of 50 U.S. airports where 5G service will be banned, as of Jan. 19. According to Reuters these airports will have mandatory buffer zones around them to prevent the service from being used. The list of airports ranges across the U.S., including major destinations like Newark Liberty International, Dallas-Forth Worth International, Chicago O’Hare International, and Los Angeles International. According to the letter sent by airline CEOs, the FAA’s decision does not grant relief to “airports that are used by most of the traveling and shipping public,” which could cause major problems and potential cancellations. “Unless our major hubs are cleared to fly, the vast majority of the traveling and shipping public will essentially be grounded. 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 CEOs stated in their letter. The executives also said that 5G is not likely to only affect the one aviation tool. “Because radio altimeters provide critical information to other safety and navigation systems in modern airplanes, multiple modern safety systems on aircraft will be deemed unusable, causing a much larger problem than what we knew,” they wrote. “Airplane manufacturers have informed us that there are huge swaths of the operating flat that may need to be indefinitely grounded. In addition to the chaos caused domestically, this lack of usable wide body aircraft could potentially strand tens of thousands of Americans overseas.” RELATED: For more travel news delivered straight to your inbox, sign up for our daily newsletter. According to NBC News, both AT&T and Verizon announced on Jan. 18 that they would temporarily limit 5G service around some airports, following the airlines’ warning about disruption. Both cell providers still plan to roll out their networks on Jan. 19, after having already delayed implementation plans from last year due to concerns laid out by the FAA. AT&T said has agreed “to temporarily defer turning on a limited number of towers around certain airport runways,” and Verizon said the same, but neither outlined which areas or airports would be limited from 5G service. Both cell providers noted that 5G service has been implemented in many different countries without the problems airlines in the U.S. have warned about, however. “The Federal Aviation Administration and our nation’s airlines have not been able to fully resolve navigating 5G around airports, despite it being safe and fully operational in more than 40 other countries,” Verizon said in a statement to NBC News. And AT&T said, “We are frustrated by the FAA’s inability to do what nearly 40 countries have done, which is to safely deploy 5G technology without disrupting aviation services, and we urge it do so in a timely manner.” RELATED: Alaska Airlines Is Getting Rid of This on Flights, Effective Immediately.