As we previously reported, the Radio Technical Committee for Aeronautics (RTCA) had warned that 5G signals from cellphones could interfere with radar altimeters aboard aircraft. Now a coalition of aviation groups has formally requested that the FCC suspend an auction for frequency allocation slated to start today. “Since 2017, the aviation industry has consistently noted during the Federal Communications Commission rulemaking process that deployment of 5G networks in this frequency band may introduce harmful radio frequency interference to radar altimeters currently operating in the globally-allocated 4.2–4.4 GHz aeronautical band,” the group wrote. “Radar altimeters are deployed on tens of thousands of civil aircraft in the United States and worldwide to support several critical safety-of-life aircraft functions throughout multiple phases of flight. Radar altimeters are the only sensor onboard a civil aircraft which provides a direct measurement of the clearance height of the aircraft over the terrain or other obstacles.”
The RTCA study “revealed that 5G telecommunications systems in the 3.7–3.98 GHz band will cause harmful interference to radar altimeters on all types of civil aircraft—including large commercial transport airplanes; business, regional, and general aviation airplanes; and both transport and general aviation helicopters,” according to the group. “Without appropriate mitigations, such interference could lead to catastrophic failures. The study was submitted to the FCC for consideration back in October and additional information was provided to the FCC today.” Specifically, the group wants the FCC to limit 5G transmitters near airports, reduce the allowable “spurious emissions” limits and limit the amount of radiated power from these 5G installations.
Associations signing the document include: Aerospace Industries Association; Airborne Public Safety Association; Air Line Pilots Association, International; Aircraft Electronics Association; Aircraft Owners and Pilots Association; Airlines for America; Cargo Airline Association; Experimental Aircraft Association; General Aviation Manufacturers Association; Helicopter Association International; National Air Carrier Association; National Air Transportation Association; National Business Aviation Association; RTCA; and Regional Airline Association.
