5G threat to aircraft
January 20, 2022 - Airlines have warned that new U.S. C-Band 5G services could interfere with aircraft instruments such as radio altimeters, which display the height between the runway and wheels when landing.
5G is the fifth generation of cellular networks -- up to 100 times faster than 4G. The European Union set its mid-range 5G frequencies in a 3.4-3.8GHz range, a lower frequency than the so-called C-Band in the U.S., defined as between 3.7-4.2GHz.
Last year, the Federal Communications Commission (FCC) authorised nearly all of the C-Band spectrum to AT&T and Verizon in an $80 billion auction.
For pilots landing, particularly in the latter stages of an approach in low visibility, knowing the aircraft’s height above the ground is vital. The radio altimeter or Rad Alt provides this data.
The U.S. Federal Aviation Administration (FAA) has raised concerns that many automated safety systems rely on Rad Alt data whose accuracy may be affected. These systems -- including terrain and ground proximity warning systems, collision avoidance, flight surface control, autothrottle and thrust reversers -- are crucial for making landings in poor visibility and for aircraft flying at low altitudes.
The FCC activation of C-band frequencies near U.S. airports on Wednesday (January 19) has resulted in airlines cancelling flights due to 5G safety concerns. British Airways Boeing 777s are particularly at risk of being affected, and the airline cancelled several flights from Heathrow to Boston, Chicago, Los Angeles, New York, and San Francisco.
Dubai-based Emirates suspended all its flights to nine U.S. airports on Wednesday, while other airlines to cancel flights include Air India, Japan-based ANA, Japan Airlines and Korean Air.