Washington (CNN Business) Executives from the largest US airlines asked the Biden administration for "immediate intervention" in the planned rollout of 5G technology near major airports on Wednesday, warning of dire consequences for transportation and the economy.
The representatives of 10 carriers asked the administration in a letter obtained by CNN to further delay the rollout near airports where Federal Aviation Administration flight restrictions take effect once the technology kicks in. The aviation world is concerned 5G signals will interfere with aviation technology including the radar altimeter onboard planes.
"The ripple effects across both passenger and cargo operations, our workforce and the broader economy are simply incalculable," the executives wrote. "To be blunt, the nation's commerce will grind to a halt."
Reuters first reported the letter.
The letter says discussions between the airlines and the telecommunications industry are ongoing. Carriers Verizon (VZ) and AT&T (T), which owns CNN's parent company, first delayed the 5G rollout until January, and then agreed to a more limited airport-focused delay that expires this week.
"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."
Verizon and AT&T declined to comment.
The letter was addressed to the White House, Transportation Department, Federal Communications Commission and FAA. Signatories to the letter include members of Airlines for America: executives with Alaska Airlines, American Airlines (AAL), Atlas Air (AAWW), Delta Air Lines (DAL), Hawaiian Airlines, JetBlue Airways (JBLU), Southwest Airlines (LUV), United Airlines, and the airline operations at FedEx (FDX) and UPS (UPS).
On Monday evening, United Airlines warned of "a devastating impact on aviation" if 5G is rolled out near airports.
"When deployed next to runways, the 5G signals could interfere with the key safety equipment that pilots rely on to take off and land in inclement weather," United said in a statement, warning that safety concerns could lead to "significant restrictions" on aircraft being able to operate at airports, including those in Houston, Newark, Los Angeles, San Francisco and Chicago.
The FAA said in a Monday evening statement that it "will continue to ensure that the traveling public is safe as wireless companies deploy 5G."
"The FAA continues to work with the aviation industry and wireless companies to try to limit 5G-related flight delays and cancellations," it said.
Some commercial planes cleared
Federal officials are easing up some of the restrictions on commercial airliners set to take effect this week when new 5G technology comes online.
The FAA said it has cleared for use two radar altimeters used in some Boeing (BA) and Airbus jets, a move that it says will allow many US commercial aircraft to make low-visibility landings at some airports.
Days ahead of the Wednesday activation, the FAA says it has lifted restrictions on about 45% of the US commercial aircraft fleet and that about 48 of 88 impacted runways will be eligible for low-visibility landings. The approvals include Boeing's 737, 747, 757, 767, MD-10 and MD-11 and the Airbus A310, A319, A320, A321, A330 and A350.
"Even with these new approvals, flights at some airports may still be affected," the FAA said in a statement. "The FAA also continues to work with manufacturers to understand how radar altimeter data is used in other flight control systems."
This article originally appeared on CNN