This week, concerns that the 5G system could interfere with the radio altimeter of planes, which is crucial for landing, were raised.
The activation of the 5G mobile phone service near American airports could disrupt planes’ navigation systems, with Boeing 777s particularly affected.
For this reason, British Airways has decided to cancel most flights to the US.
All flights from Heathrow to Boston, Chicago, Los Angeles, New York, and San Francisco were cancelled on Wednesday.
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British Airways said: “Safety is always our priority and although we had to cancel a handful of services, we’ve done everything we can to minimise inconvenience for our customers.
“We’ve changed the aircraft operating some of our flights and rebooked those on cancelled services onto alternatives.
“We’re disappointed that, like other airlines, some of our customers’ travel plans have been disrupted.”
Emirates cancelled all its flights to the US “until further notice”.
Other airlines such as Air India, Japan-based ANA, Japan Airlines, and Korean Air made cancellations.
Virgin Atlantic, which does not operate Boeing 777s, said all their flights are going ahead as usual.