Coalition Concerned About Radio Altimeter Interference

 - May 29, 2020, 11:41 AM

Garmin and other avionics manufacturers, aircraft manufacturers, and aviation industry associations have formed a coalition and petitioned the U.S. Federal Communications Commission (FCC) to reconsider a move that could affect radio altimeters in aircraft. The FCC has approved the repurposing of C-band frequencies for 5G and other “flexible-use” telecommunications, but according to the coalition, radio altimeters aren’t fully protected from interference from these C-band uses. 

The petition for reconsideration asks the FCC “to reconsider its Report and Order to repurpose C-band frequency spectrum nearby to the frequency band that is used by safety-critical FAA-certified radio altimeters, including Garmin’s GRA 5500 and GRA 55,” according to Garmin. “Radio altimeters are essential to safe airplane and helicopter operations, allowing pilots to safely land and avoid terrain, particularly during poor weather conditions and low visibility. The industry coalition is working to ensure radio altimeters are appropriately protected from prospective flexible-use applications, including 5G operations.”

The coalition doesn’t agree that “the C-band Report and Order [is] ‘carefully designed so that aircraft are able to use [radio] altimeters in a continuous and uninterrupted manner,’” according to a Garmin statement. The FCC had assured the U.S. Congress that radio altimeters would not be affected. “The industry coalition does not seek to block repurposing the C-band spectrum. Instead, the coalition seeks a path that will make the C-band spectrum available for purposes such as 5G, while ensuring full protection of radio altimeters,” Garmin added.