The distress in the friendly skies appeared to be abating on Thursday, but fear that the rollout of 5G in the United States would interfere with crucial aircraft systems continued to disrupt US-bound flights.

Bermuda seemed little affected, as travellers elsewhere saw many flights cancelled, at least until the 5G providers agreed to delay implementing the technology for two weeks.

The Bermuda Civil Aviation Authority (BCAA) had already taken a cue from the European Aviation Safety Agency and the Federal Aviation Authority (FAA) in United States. It warned aircraft operators of a potential air safety hazard.

The concern — first identified in the US — was raised because of the risk of interference from 5G mobile technology to radio altimeters in aircraft.

And while the flight cancellations began growing earlier this week, it became clear on Thursday that officials had gathered far more information. Airlines at first wanted 5G to be banned within two miles of airports.

But BCAA director of operations Tariq Lynch-Wade conceded: “It is an evolving topic. It has caused quite a stir globally, particularly amongst airlines.

“Locally it’s been an ongoing effort particularly among local stakeholders because what we are trying to ascertain is whether or not the potential affects to aviation here on island will require us to implement any protection measures. Those conversations are still ongoing among the stakeholders.

“The notice I published earlier was more so for awareness, so that aircraft operators should be looking into how 5G could affect their particular (equipment).

“The manufacturers would be the best to let them know how the C-band affects their operation. They need to follow the guidance put out by the respective authorities.”

Notices were issued just as major 5G systems were about to be launched this month in the US.

Although 5G has been approved for use in Bermuda by the Regulatory Authority, no word has been given as to when it will be launched.

The authority told The Royal Gazette this week: “The RA’s board of commissioners lifted the moratorium on 5G last year and are not involved in discussions regarding the planned use of 5G.

“In essence, it is now up to providers in the electronic communications sector to decide when they will launch the technology.”

Both Digicel Bermuda and One Communications have confirmed they have no intention of introducing 5G technology in Bermuda in the near future.

Bermuda Airport Authority chief executive officer Lester Nelson confirmed that local officials are up to date on the issue.

He said: “We have a local team of air traffic controllers and we also have an agreement with the FAA.

“They are the lead agency, and with the FCC, I guess, in the United States who have expressed concerns about 5G. Our co-ordination is directly with the FAA and we are guided accordingly. We work closely with them. They have the resources, with the FCC, to determine whether there is an issue.”

But the concern level heightened as the FAA began working on measures to ensure that radio signals from newly activated wireless telecommunications systems can coexist safely with flight operations in the United States. They had input from the aviation sector and the telecommunications industry.

5G services were planned for launch on Wednesday using frequencies in a radio spectrum called the C-band. These frequencies can be close to those used by radar altimeters, an important piece of safety equipment in aircraft.

The bosses of major US air carriers for both passengers and cargo warned that the planned launch on Wednesday of the new C-band 5G service could render a number of the aircraft unusable, strand thousands of passengers and cause chaos for US flights.

The BCAA operations notice signed and issued by Mr Lynch-Wade this month was headlined: “Potential Interference Risk to Radio Altimeters from 5G Mobile Technology”.

The notice sought to raise awareness of the potential interference to radio altimeter systems from the ground-based 5G telecommunications infrastructure.

Radio altimeters provide highly accurate information about an aircraft’s height above the ground, as well as data that informs other safety equipment on the plane, including navigation instruments, terrain awareness and collision-avoidance systems.

The BCAA notice stated: “Although the BCAA has no jurisdiction over radio spectrum management and the allocation of spectrum, we do have a responsibility for aviation safety in the territory and operators on our register.

“Some countries have introduced temporary technical, regulatory or operational mitigations on mobile telecommunications providers and/or aviation industry to mitigate against the potential risk of interference.”

FAA officials said 5G was already being deployed in other countries, such as France and Japan, with no issues. But the US is different because US airspace is the most complex in the world, and the FAA holds the aviation sector to the highest safety standards.

The deployments of 5G technology in other countries also often involve different conditions than those proposed for the US.