Airlines including Emirates, Lufthansa and Air India have canceled or changed flights to the US due to concerns about the proliferation of 5G mobile phone technology near airports.
The U.S. Aviation Watchdog has said that 5G signals can interfere with radio altimeters, which measure how high an airplane is in the sky, and are a crucial piece of equipment for pilots, especially when landing in bad weather.
The Federal Aviation Authority (FAA) on Tuesday began updating its guidance on which airports and aircraft models would be affected. Airlines say the Boeing 777 is in the spotlight in the first place.
AT&T and Verizon, the two wireless providers behind the 5G plans, said they would pause the rollout near major airports, which should take place on Wednesday.
But Dubai-based Emirates, the world's largest operator of 777s, announced on Wednesday that it would halt flights to Boston, Chicago, Dallas-Fort Worth, Houston, Miami, Newark, New Jersey, Orlando, Florida, San Francisco and Seattle on because of the problem. It said it would continue flights to Los Angeles, New York and Washington.
In its announcement, Emirates said the cancellations were due to "operational concerns associated with the planned deployment of 5G mobile network services in the United States at certain airports".
Japan's two major airlines, All Nippon Airways (ANA) and Japan Airlines, said they would curtail Boeing 777 flights. ANA said it was canceling or modifying the aircraft used on some U.S. flights.
Air India announced it would cancel flights to Chicago, Newark, New York and San Francisco "due to the proliferation of 5G communications equipment". It said it would try to use other aircraft on U.S. routes.
Germany's Lufthansa said it had canceled a flight from Frankfurt to Miami and switched planes used on some US services from Boeing 747-8 to 747-400. Its subsidiary Austrian Airlines said it would switch from a 777 to a 767 on its Newark service.
Korean Air said it had switched away from 777s and 747-8s on six U.S. passenger and cargo flights. Taiwan's China Airlines said it would reroute some flights, and Hong Kong's Cathay Pacific Airways said it would deploy different types of aircraft if necessary.
The airlines said they were acting in response to a message from Boeing that 5G signals could interfere with the 777 radio altimeter, leading to restrictions.