Major international airlines have rushed to rejig or cancel flights to the US ahead of a 5G wireless roll out on Wednesday that has triggered safety concerns, despite two wireless carriers saying they will delay parts of the deployment.
AT&T and Verizon agreed on Tuesday to a partial delay in activating their 5G networks following an outcry from US airlines, who said the rollout could lead to travel chaos.
Emirates airline was one of several aviation companies that announced it will suspend flights to several US destinations as of 9.01am on Wednesday.
Why has the 5G rollout affected flights?
Telecom giants spent tens of billions of dollars to obtain 5G licences, but as the launch date approached aviation industry groups raised concerns about possible interference with aircrafts' radio altimeters – which can operate at the same frequencies – particularly in bad weather.
Radio altimeters give precise readings of the height above the ground on approach and help with automated landings, as well as verifying the plane has landed before allowing reverse thrust. Altimeters operate in the 4.2-4.4 GHz range and the concern is that the auctioned frequencies sit too close to this range.
Which airlines have been affected by the 5G rollout?
The heads of 10 passenger and cargo airlines, including American, Delta, United and Southwest, said 5G will be more disruptive than they originally thought because dozens of large airports that were to have buffer zones to prevent 5G interference with aircraft will still be subject to flight restrictions announced last week by the Federal Aviation Administration, and because those restrictions will not be limited to times when visibility is poor.
The world's largest operator of the Boeing 777, Dubai's Emirates, said it would suspend flights to nine US destinations from January 19, the planned date for the deployment of 5G wireless services.
Emirates flights to New York's JFK, Los Angeles and Washington DC will continue to operate.
Emirates airline president Sir Tim Clark said he was unaware of the potential danger posed by the introduction of 5G networks in the US until Tuesday morning. Speaking on CNN, Mr Clark described the situation as "one of the most delinquent, utterly irresponsible" in his aviation career.
"We were not aware of this until Tuesday morning, to the extent it was going to compromise the safety of operation of our aircraft and just about every other 777 operator to and from the United States and within the United States," Mr Clark told CNN's Richard Quest.
Etihad Airways’s services to the US, meanwhile, are not currently affected by the introduction of 5G networks. The national airline of the UAE will continue to operate flights to New York, Washington DC and Chicago as scheduled, the airline said on Wednesday.
Japan's two major airlines, All Nippon Airways (ANA) and Japan Airlines (JAL), said they would curtail Boeing 777 flights.
ANA said it was cancelling or changing the aircraft used on some US flights. JAL said it would not use the 777 on US mainland routes "until safety is confirmed," according to a notice to passengers reported by airline publication Skift.
Korean Air said it had switched away from 777s and 747-8s on six US passenger and cargo flights and expected to also change planes used on another six flights on Wednesday.
Taiwan's China Airlines said on Wednesday it would reschedule some flights, while Hong Kong's Cathay Pacific Airways said it would deploy different aircraft types if needed.
The airlines said they were acting in response to a notice from Boeing that 5G signals may interfere with the radio altimeter on the 777, leading to restrictions.
What is 5G exactly?
Fifth generation of cellular mobile technology, or 5G, will enable rapid data transfer, energy saving, cost reduction and widespread device connectivity through the Internet of Things.
5G networks rely on denser arrays of small antennas and the cloud to offer data speeds up to 50 or 100 times faster than current 4G networks and serve as critical infrastructure for a range of industries.
By 2025, 1.2 billion people are set to have access to 5G networks – a third of them in China, according to the global wireless trade group GSMA.
Unlike the upgrades of cellular standards 2G in the early 1990s, 3G around the millennium and 4G in 2010, 5G standards will deliver not just faster phone and computer data but also help connect cars, machines, cargo and crop equipment.
How can this be fixed?
In the short-term, AT&T and Verizon agreed to temporarily defer turning on some wireless towers near key airports to avert a significant disruption to US flights. Read more
Longer-term, the FAA needs to clear and allow the vast majority of the US commercial airplane fleet to perform low-visibility landings at many airports where 5G C-band will be deployed. This means certifying altimeters to operate near 5G base stations.