Discussions are centred around that proposal that would also allow about 90% of the wireless tower deployment to go forward, sources told Reuters, though it would impact 5G deployment near many large population centres.
Two of the sources said it would require delaying just over 500 towers from being activated near airports. The vast majority are Verizon towers.
"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," AT&T said.
The announcement came as the White House is working to prevent a massive disruption in flights ahead of Wednesday's scheduled 5G deployment and actively engaged on the issue, a senior official said.
Airlines are preparing to cancel a significant number of passenger and cargo flights in the coming hours to prepare for new 5G C-Band service that starts on Wednesday, after warning on Monday of "catastrophic" impacts. Airlines are concerned that the issue could prevent them from flying Boeing 777s and other widebody jets to many key airports.
The chief executives of major US passenger and cargo carriers on Monday said new 5G service could render a significant number of widebody aircraft unusable, "could potentially strand tens of thousands of Americans overseas" and cause chaos for US flights.
Airlines have urged wireless carriers to not turn on some wireless towers near airport runways in a bid to avoid most of the flight disruptions.
The Federal Aviation Administration (FAA) has warned that potential interference could affect sensitive aeroplane instruments such as altimeters and significantly hamper low-visibility operations.
The airlines asked Sunday "that 5G be implemented everywhere in the country except within the approximate 2 miles (3.2 km) of airport runways" at some key airports.
Verizon's rollout plan is much more aggressive than AT&T's. It is significantly impacted by the Biden administration request to delay using some towers near airport runways.
Alaska Airlines Chief Executive Ben Minicucci said Tuesday in a statement "there’s a serious threat of mounting cancellations, delays and diversions of our passenger and cargo flights if action is not taken immediately."
AT&T and Verizon, which won significant C-Band spectrum in an $80 billion auction last year, on Jan 3 agreed to buffer zones around 50 airports to reduce interference risks and take other steps to cut potential interference for six months. They also agreed to delay deployment for two weeks until Wednesday.
Verizon Chief Executive Hans Vestberg told employees on Jan 4 the carrier saw no aviation safety issue with 5G, but reluctantly agreed to a two-week delay that expires Wednesday. Verizon did not comment Tuesday.
"Unless our major hubs are cleared to fly, the vast majority of the travelling and shipping public will essentially be grounded," wrote the chief executives of American Airlines, Delta Air Lines, United Airlines, Southwest Airlines and others.