Don't Ignore C-Band Threats to Air Safety: Garmin to FCC

Garmin representatives met with an aide to Chairwoman Jessica Rosenworcel and others from the FCC to answer questions on the interference risks 5G poses for radio altimeters (see 2111150071), said a filing posted Tuesday in docket 18-122. “The discussion included how radar altimeters used during Aerospace Vehicle Systems Institute (AVSI) testing failed when subjected to simulated 5G interference sources,” it said: “While some radar altimeters were observed to fail by outputting a No Computed Data (NCD) status, many failed in a manner where a misleading height above ground was output without a simultaneous NCD status.” The Radio Technical Commission for Aeronautics defended its now-updated report. The multistakeholder group report was “informed by detailed information made available by the commercial wireless and aviation industries regarding their respective systems and was therefore able to more thoroughly examine issues of compatibility between existing radar altimeters and prospective flexible use licensees than were the earlier preliminary analyses,” the group said: “The analysis found serious threats of harmful interference to today’s installed radar altimeters from anticipated flexible use licensed deployments, including from spurious emissions into the radar altimeter band.” Calls that the report be dismissed “have not been validated by hard science or engineering analysis,” RTCA said.