FreeFlight Develops Drop-in 5G Radar Altimeter Solution
March 10, 2022
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  • FreeFlight Systems (Booth 8239) has developed a drop-in 5G interference mitigation solution for its RA-4000 and RA-4500 radar altimeters (radalts). The company’s new RA-4500 Mark II upgrade uses the existing wiring, structural, and antenna provisions already on the aircraft, and is available for all customer installations. RA-4000 and RA-4500 radalts have been installed in more than 5,000 aircraft.

    AT&T and Verizon 5G wireless signals in the 3.7- to 3.98-GHz range bump up against radar/radio altimeters in the 4.2- to 4.4-GHz environment, causing those altimeters to give potentially false readings to pilots and the various aircraft systems they support. While the wireless carriers are working together with the FAA to mitigate interference at the nation’s busiest airports, helicopters—which frequently operate in non-airport environments—remain particularly susceptible to this interference.  

    “To address the restrictions imposed by the published FAA ADs, we recommend existing RA-4000 and RA-4500 customers to upgrade to the RA-4500 MK II to mitigate the effects of 5G infrastructure to continued flight operations,” said FreeFlight president Anthony Rios. “We will support our customers in navigating the alternative means of compliance submission process with data, expertise, and collateral materials as needed in the process.” 

    FreeFlight noted that “many currently fielded radalts including the RA-4000 and RA-4500 have been found to be susceptible to incorrect altitude readings due to C-band 5G interference.” Those altimeters were designed and certified between 2008 and 2009—long before the effects of 5G interference were known. The company’s new RA-5500 and RA-6500 are designed to mitigate 5G and other radio frequency interference with internal filtering and digital signal processing.