British Airways is among the airlines canceling flights in the US due to 5G security concerns.
The action responds to fears that the activation of C-band mobile phone service near US airports on Wednesday could disrupt aircraft navigation systems.
Boeing 777s are believed to be at particular risk of being affected.
The introduction of the technology has stopped in some parts of the US, but continues elsewhere.
Britain’s Civil Aviation Authority, CAA, said it has “issued safety advice” to airlines.
British Airways had canceled a handful of flights from Heathrow to Boston, Chicago, Los Angeles, New York and San Francisco on Wednesday.
The airline said in a statement: “Safety is always our priority. We are closely monitoring the situation in the US and will continue to review our timeline in the coming hours.
“We are disappointed that some of our customers are facing potential disruptions and will update them as soon as possible on any changes to their travel plans.”
The airline said some flights that were to be operated by Boeing 777s were using different, larger planes, such as the Airbus A380, to ensure people can still fly on the same day they booked.
Other airlines have made far more cancellations.
Emirates suspended all its flights to nine US airports on Wednesday until further notice.
The Dubai-based carrier told customers the move was due “to operational concerns associated with the planned rollout of 5G mobile network services in the US at certain airports.”
He added that Emirates regrets any inconvenience caused, “we are working closely with aircraft manufacturers and relevant authorities to alleviate operational concerns, and look forward to resuming our services in the US as soon as possible.”
Other airlines that have canceled flights include Air India, Japan-based ANA, Japan Airlines and Korean Air.
Virgin Atlantic, which does not operate Boeing 777s, said it has made no cancellations or changes to aircraft types.
Concern about 5G in the US relates to its potential effect on aircraft altimeters, which measure altitude.
This has no impact on UK airports because the US uses a different frequency for 5G.
A CAA spokesperson 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 Defense to ensure that the UK 5G rollout does not cause any technical issues for aircraft and we are keeping our position under constant review.
“Also, as UK aircraft fly around the world, we have issued safety advice to airlines on the status of 5G in other countries, including the US.”
Source: NAN
