AT&T delays 5G wireless service near airports after airlines’ safety warning
AT&T will postpone new wireless service near some airports planned for this week after the nation’s largest airlines said the service would interfere with aircraft technology and cause huge flight disruptions.
The company said on Tuesday it would delay turning on new cell towers around runways at some airports – it did not say how many – and work with federal regulators to settle a dispute over potential interference from new 5G service.
The decision came after the airline industry raised the stakes in a showdown with AT&T and Verizon over plans to launch new 5G wireless service this week, warning that thousands of flights could be grounded or delayed if the rollout takes place near major airports.
Verizon and a trade group for the telecom industry, CTIA, did not immediately respond to requests for comment.
On Monday, CEOs of the nation’s largest airlines said that interference from the wireless service will be worse than they originally thought.
“To be blunt, the nation’s commerce will grind to a halt” unless the service is blocked near major airports, the CEOs said in a letter to federal officials including the transportation secretary, Pete Buttigieg, who has previously taken the airlines’ side in the matter.
The airlines asked that the new, faster mobile service be banned within two miles of runways.
AT&T and Verizon planned to activate their new 5G wireless service on Wednesday after two previous delays from the original plan for an early December rollout.
The new high-speed 5G service uses a segment of the radio spectrum that is close to that used by altimeters, which are devices that measure the height of aircraft above the ground. Pilots use altimeters to land when visibility is poor, and they link to other systems on planes.
AT&T and Verizon say their equipment will not interfere with aircraft electronics, and that the technology is being safely used in many other countries. Robert Mann, an airline industry expert, said the issue around 5G goes beyond commercial airlines and into every area of aviation, from medvac helicopters to private aviation.
“It applies not only at or near airports, but it disrupts terrain avoidance, weather services and navigation services that aircraft have come to rely on,” Mann said. “The irony is that this issue has been well-known for over a decade but was overlooked or consciously avoided when telecoms firms were granted the franchises.”
In 2020, the Radio Technical Committee for Aeronautics (RTCA) published a white paper warning that interference from 5G nodes near airports could interfere with altimeters.
“Radar altimeters are the only sensor onboard a civil aircraft, which provides a direct measurement of the clearance height of the aircraft over the terrain or other obstacles, and failures of these sensors can therefore lead to incidents with catastrophic results resulting in multiple fatalities,” the assessment said.
The spectrum used by C-Band 5G was auctioned off to the telecoms companies in the waning days of the Trump administration by commerce secretary Wilbur Ross. The danger to aircraft is that the new 5G transmitting nodes, with more power but lower range than their 4G predecessors, are far more powerful than those used by a plane’s guidance equipment.
With far more 5G nodes needed for continuous service, the frequencies can bleed into adjacent frequencies – the frequencies used by altimeters on take-off and approach – as well as collision avoidance and wind-shear technology. Those systems are integrated into a plane’s systems management and cannot easily be upgraded.
Mann said: “We have a very safety conscious industry on one hand, in which if customers have to worry about safety or reliability they’re not interested in the service at all, and on the other, a swash-buckling, let’s-make-adeal telecoms that wants to sell you a fast video download without regard to its effect on others.”
Mann said the FCC and other agencies were well aware of potential conflicts before the bandwidth was auctioned off for $80bn in January last year. But, unlike a corresponding sale in Canada, the sale did not include regulation about proximity to airports, the orientation and power of transmitting nodes.
He said: “Why we’re at this point I simply don’t know. It was well-known and apparently ignored. But it wasn’t ignored by the aviation industry and the FAA. I think the FAA thought, ‘Well, they can’t possibly do this, so why worry about it’.”