Global airline body flags risks from 5G-related interference; no such cases in Singapore so far

SINGAPORE – There have been no cases of 5G-related interference affecting aircraft operations in Singapore so far, but the Civil Aviation Authority of Singapore (CAAS) is continuing to monitor developments closely as the technology evolves globally.

This comes as the International Air Transport Association (IATA), the global airline industry body, on Dec 9 flagged concerns about potential 5G interference with aviation systems, which could pose safety risks.

Airline pilots operating in Singapore have not reported any interference issues, said Mr Foong Ling Huei, director of flight standards at CAAS.

The authority has been working closely with the Infocomm Media Development Authority (IMDA), local telecommunications companies and international aviation regulators to assess the potential impact of 5G technology on aviation.

“The 5G network in Singapore uses a frequency band of 3.45 GHz to 3.65 GHz, which is far away from that used by aircraft radio altimeters at 4.2 GHz to 4.4 GHz,” Mr Foong said on Dec 12.

He added that 5G base stations in Singapore also operate at relatively low power emission levels, further reducing the risk of interference.

“Taken together, these factors significantly lower the risk of any potential interference with aircraft radio altimeters,” he said.

Radio altimeters are electronic devices that measure an aircraft’s height above the ground by transmitting radio waves downward and timing their reflection. This is particularly critical during landing, when precise altitude information is required for automated systems and pilot decision-making.

CAAS has also conducted live trials locally, which did not flag any significant interference to aircraft operations, Mr Foong said on Dec 12.

The authority will continue to work with IMDA, local telcos and international counterparts to ensure the safe coexistence of 5G – and eventually 6G – networks with aviation systems.

National carrier Singapore Airlines and its budget subsidiary Scoot, as well as Hong Kong carrier Cathay Pacific, said there have been no reported or confirmed cases of 5G interference involving their aircraft.

An IATA spokesperson said interference mainly comes down to how much power is used and which frequency bands are allocated.

For example, Canada plans to expand 5G operations into the 3.90 GHz to 3.98 GHz band in 2026. To prevent any impact on air traffic, mitigation measures will remain in place until June 2026, the spokesperson said. This will give telecom and aviation regulators time to agree on a practical approach that works for both industries, the spokesperson added.

SIA, Scoot and Cathay Pacific added that they are closely monitoring developments and will comply with regulatory requirements.

Cathay Pacific said it has also taken steps to mitigate potential risks, including upgrading the radio altimeters on its Boeing 747 freighter fleet between 2022 and 2023 to make them 5G-tolerant and compliant with regulatory and industry guidelines.

Globally, concerns about potential 5G interference with aviation systems remain an issue.

The topic was raised on Dec 9 at IATA’s global media day in Geneva, Switzerland, where it discussed the challenges posed by differing national approaches to spectrum use.

“Right now, there are no real standards internationally on how to deal with 5G, so we’re going to continue to try to work with regulatory fragmentation, primarily through ICAO,” said Mr Nick Careen, IATA’s senior vice-president for operations, safety and security, referring to the International Civil Aviation Organization.

In 2022, the US Federal Aviation Administration (FAA) reportedly said it had received reports from pilots about suspected 5G interference affecting aircraft instruments, especially radio altimeters.

The FAA noted possible 5G-related anomalies where aircraft systems behaved strangely near 5G networks, but none affected critical controls or caused accidents.

A 5G network refers to the fifth generation of mobile technology, offering faster data speeds, lower latency – or delays in connection – and the ability to connect many more devices than previous generations such as 4G.

But aviation depends on a protected set of radio frequencies that allow pilots and air traffic controllers to communicate, navigate and exchange critical flight data, including weather information, noted Mr Careen.

In a presentation to the media, he said that interference-free access to these frequencies is essential for global aviation safety. Without it, the air transport system can be exposed to operational disruption and safety risks.

While the International Telecommunication Union – the United Nations agency for digital technologies – allocates aviation frequencies at a global level, countries regulate neighbouring spectrum bands differently, said Mr Careen.

In some markets, 5G networks operate close to aviation frequencies and sometimes at higher power levels.

This uneven regulatory landscape has created uncertainty for airlines, particularly as more high-power telecommunications systems are deployed near airports and flight paths, Mr Careen said.

According to IATA, interference risks generally stem from two sources.

Modern telecoms systems operating close to aviation bands can unintentionally spill into aircraft frequencies.

At the same time, some older aircraft systems were not designed for today’s dense, high-power radio environment and have limited filtering capability, Mr Careen said.

Interference can disrupt communications and navigation systems, leading to delays, rerouting and runway restrictions, he noted. When automation is compromised, pilots and air traffic controllers must rely on more manual procedures, increasing workload and reducing efficiency.

“Obviously, any time you introduce manual processes in what has become a pretty automated environment in the cockpit, we also introduce greater risk,” Mr Careen said.

He gave the example of the radio altimeter, which is among the most sensitive systems.

In several countries, 5G frequencies sit directly next to the altimeter band. While more resilient altimeter designs are being developed, they are not expected to be widely available until around 2032, he said.

In the meantime, voluntary safeguards involving power limits and antenna adjustments, among other things, are due to lapse in 2026 in some countries including Australia and Canada, and in 2028 in the US. This will create a timing gap that the aviation authorities and industry players are working to manage, Mr Careen said.

“(As) the new equipment won’t be available until between 2032 and 2035, we’ve got a problem for the next 10 years or so,” he told reporters.

The safeguards include pointing antennas away from the airport, and lowering the frequency at which these operate.

IATA called for greater global harmonisation of standards and closer cooperation between telecoms and aviation authorities, including transparent access to data on 5G deployments at and around airports.

Additional reporting by Isabelle Liew