Airlines serving the US might be required to cancel flights this summer as they struggle to meet the Federal Aviation Administration’s (FAA) deadline to upgrade radio altimeters to avoid interference with 5G networks. But some question whether such measures are necessary.
Next-generation 5G mobile networks launched in the US in January 2022, using spectrum in the C-band. The frequencies are close to those used by aircraft radio altimeters, which provide highly accurate information about an aircraft’s height above the ground, sparking fears the networks may interfere with equipment performance.
The data from radio altimeters informs other safety equipment on the aircraft such as navigation instruments, terrain awareness and collision avoidance systems. Interference with the equipment could be hazardous.
To avoid any potential life-threatening situations, the FAA placed a requirement on aircraft to have radio altimeters to have minimum performance levels for low-visibility landing procedures. Any altimeters that do not meet the performance level required by the federal government would have to be replaced or upgraded at the expense of the airline.
According to the International Air Transport Association (IATA), the cost of a fleet-wide radio altimeter upgrade for an airline is estimated to be over $638m.
US telcos have delayed the full 5G rollout around airports until 2028
The 5G safety concerns around radio altimeters have resulted in US telco operators such as AT&T, T-Mobile, UScellular and Verizon slowing their full roll-out of 5G services in the US. The collective agreed to extend voluntary mitigation measures for the 5G C-band transmissions at 188 US airports until January 2028, according to IATA. It was originally expected to end in July.
While the extension is welcomed, IATA said in a statement that the industry had been trying to work with the FAA and telco operators over the risks to aviation operations “for years” but that they had only been addressed at the eleventh hour when the telcos agreed to power limits for 5G transmissions near airports. The FAA deems the risk still to be enough to warrant restrictions on airlines during low visibility conditions.
“Airlines did not create this situation, they are victims of poor government planning and coordination,” said Nick Careen, IATA’s senior vice president of operations, safety and security. “Industry concerns about 5G, expressed for many years in the appropriate forums, were ignored and overridden.
“Half-measure solutions have been foisted upon airlines to implement at their own expense and with little visibility into their long-term viability,” he continued. “This extension is an opportunity for all stakeholders, including telcos, government regulators, airlines and equipment manufacturers, to work together for a fair and equitable solution.”
5G safety: Why could US flights be delayed or grounded in 2023?
The FAA announced in May 2022 that airlines would need to replace radio altimeters by July 1 to meet their new minimum performance standards. Regardless of the voluntary measures taken by the US telcos, the US government is not extending its retrofit deadline.
IATA say that several airlines began their upgrade process shortly after the communication from FAA, but that supply chain issues have added delays. It believes it is unlikely that the July 1 deadline will be met, which could cause operational disruptions during peak travel seasons in the country.
The association says that the latest agreement from the telcos doesn’t address the underlying issues airlines face. The retrofits required are a “temporary fix” because they are not “sufficiently resilient” against full-power 5G C-band transmissions.
New 5G tolerant radio altimeter standards are being developed, but IATA says they are not expected to be approved before the second half of 2024. “Following that, [radio altimeter] makers will begin the lengthy process to design, certify and build the new devices for installation in thousands of existing aircraft, as well as for all new aircraft delivered between now and 2028. Four-and-a-half years is a very tight timeframe for the scale of this undertaking,” the association said in a news release.
“These investments will bring no gains in operating efficiency,” warned Careen. “This is patently unfair and wasteful. We need a more rational approach that does not place the entire burden for addressing this unfortunate situation on aviation.”
FAA ‘using scaremongering tactics” to protect private pilots
Telco analyst, John Strand, founder of Strand Consulting, told Tech Monitor that the US federal department is providing cover for private plane owners who do not want to upgrade equipment.
“It is unfortunate that the FAA takes to scaremongering tactics, but that is what they do,” Strand says. “Unlike 5G networks, which are based on internationally recognised standards by the 3GPP, there is no such body which ensures that altimeters are up to date.”
He adds: “The FAA is just providing cover for owners of thousands of old planes, mainly small private planes, whose owners have ‘too deep pockets and too short arms’ to upgrade to modern equipment.
“It’s amazing that they’re allowed to fly. Would we allow cars on the road which couldn’t measure speed?”
Strand says US President Joe Biden has shown a lack of leadership when it comes to US regulatory agencies like the FAA. He points to other countries such as Japan that have not had the same 5G safety concerns as the US, as agencies have coordinated better.
“In any event, US wireless providers have gone out of their way to accommodate the FAA and pilots,” Strand continued. “It has been known for at least five years that this spectrum would be used for 5G. The FAA just pretended that it wasn’t going to happen. This situation was entirely avoidable.”