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FreeFlight Systems Introduces 5G Tolerant Radar Altimeter Upgrade for Existing Customers

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FreeFlight Systems RA-4500 MK II

DALLAS, TX, MARCH 9, 2022 – FreeFlight Systems, a NextGen aviation leader specializing in avionics design, development, and manufacturing, today announced the launch of the RA-4500 Mark II (MK II) radar altimeter (RADALT) as an upgrade path for FreeFlight Systems RA-4000 and RA-4500 customers. The RA-4500 MK II upgrades existing RA-4000 and RA-4500 installation with a robust 5G mitigation solution.

With the Federal Communications Commission (FCC) approving the use of a previously reserved Radio Frequency (RF) spectrum in the lower C Band in support of 5G systems deployment, 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.

During recent testing, many currently fielded RADALTs from various manufacturers, including the FreeFlight Systems’ RA-4000 and RA-4500, were shown to be vulnerable to strong C Band 5G RF interference. While FreeFlight Systems’ new TERRAIN Series RA-5500 and RA-6500 have been designed to mitigate C Band 5G interference, the previous RA-4000 and RA-4500 RADALTs were designed and certified between 2008 and 2009 before the effects of 5G interference were known.

“Our RA-4000 and RA-4500 units are currently safely supporting flight operations on over 5,000 aircraft worldwide,” notes Anthony Rios, President at FreeFlight Systems. “However, having foreseen the potential deployment of C Band 5G back in 2019, we understood that our customers would need a robust, clean sheet designed radar altimeter that would be tolerant to C Band 5G while being simple to install and cost-effective to upgrade from existing radar altimeters.”

For aircraft with existing RA-4000 and RA-4500 RADALTs, FreeFlight Systems is introducing the RA-4500 MK II radar altimeter as a simple drop-in replacement that utilizes the existing wiring, structural, and antenna provisions already on the aircraft. This ensures operators can quickly address the risk of 5G interference and FAA Airworthiness Directives (ADs) with no modifications to existing aircraft provisions. This path for upgrade is available to all FreeFlight Systems customers ranging from business aviation, general aviation, military and defense, uncrewed aviation, and rotorcraft platforms.

“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 effects of 5G infrastructure to continued flight operations,” says Anthony Rios. “As experts in radar altimetry and the 5G space, we will support our customers in navigating the AMOC submission process with data, expertise, and collateral materials as needed in the process.”

FreeFlight Systems’ new line of radar altimeters, the TERRAIN Series, is available to those who are not current customers of FreeFlight Systems’ RA-4000 or RA-4500 radar altimeters. The TERRAIN Series utilizes a unique combination of internal filtering and Digital Signal Processing (DSP) technology that can tolerate out-of-band 5G interference as well as other RF interferences. The TERRAIN Series radar altimeters are Design Assurance Level (DAL) B and support both single and dual installation requirements.

FreeFlight Systems is now fielding orders for the RA-4500vMK II as well as the new TERRAIN Series radar altimeters. To service customers most effectively, FreeFlight Systems has reserved limited quantities for customers who place orders during the HAI HELI-EXPO from March 8th to March 10th. To order, please see us at Booth 8239 or contact

For more information on FreeFlight Systems’ products and solutions, please visit

About FreeFlight Systems
As NextGen aviation leader, FreeFlight Systems designs and manufactures high-performance avionics for flight safety. These solutions deliver substantial safety and unmatched reliability that is critical for modern flight operations. Founded in 2001 and based in Texas, the company pioneered the first certified aviation WAAS/GSP receiver and their first rule-compliant UAT ADS-B system. FreeFlight Systems is now a global aerospace leader, specializing in SBAS/GNSS sensors, radar altimeters, flight management systems and other NextGen aerospace avionics. For more information, visit

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