Why airlines, including British Airways and Emirates, are cancelling US flights over 5G fears
Several airlines - including British Airways and Emirates - have cancelled flights to the US over concerns that 5G signals could disrupt some airplanes' navigation systems.
A new set of airway frequencies - referred to as C-band - were activated for the mobile phone service near US airports on Wednesday.
And there are concerns the new technology could affect navigation systems for Boeing 777 airplanes in particular.
The activation of the new 5G airwaves has been halted in some parts of the US.
British Airways cancelled a handful of flights from Heathrow to Boston, Chicago, Los Angeles, New York, and San Francisco on Wednesday.
The airline said: “Safety is always our priority. We are monitoring the situation in the US closely and will continue to review our schedule in the next few hours.
“We’re disappointed that some of our customers are facing potential disruption and will update them as soon as possible on any changes to their travel plans.”
It said other flights that would've originally been operated by Boeing 777s will be switched to different, larger aircraft, such as the Airbus A380.
Emirates suspended all its flights to nine US airports on Wednesday “until further notice”.
It told customers the measure was “due to operational concerns associated with the planned deployment of 5G mobile network services in the US at certain airports”.
It added: “Emirates regrets any inconvenience caused. We are working closely with aircraft manufacturers and the relevant authorities to alleviate operational concerns, and we hope to resume our US services as soon as possible.”
Other airlines to cancel flights include Air India, Japan-based ANA, Japan Airlines, and Korean Air.
Virgin Atlantic, which does not operate Boeing 777s, has not made any cancellations.
A spokesman said it is in “constant communication with regulatory bodies and aircraft manufacturers” to ensure it complies with safety directives.
The concern over 5G in the US relates to its potential effect on altimeters, a device on planes that measures altitude.
UK airports are not affected because the US uses a different frequency for 5G.
The UK’s Civil Aviation Authority (CAA) said it has also “issued safety advice” to airlines.
A spokesman said: “There have been no reported incidents of aircraft systems being affected by 5G transmissions in UK airspace.
“We are working with Ofcom and the Ministry of Defence to make sure that the deployment of 5G in the UK does not cause any technical problems for aircraft and are keeping our position under constant review.
“Also, as UK aircraft fly throughout the world we have issued safety advice to airlines on the 5G status in other countries, including the USA.”