TERRAIN SERIES RA-5500 & RA-6500 Retrofit Flexibility for Mixed Fleets Multi-interface connectivity and flexible installation options for commercial, military and next-generation platforms, in single or dual configurations. Empowering safer flights and faster installs, the RA-5500 and RA-6500 deliver accuracy and reliability with seamless integration and minimal downtime for retrofit installation. An analog output interface supports legacy aircraft integration, so a single solution serves aircraft on glass and aircraft on existing indicators. Analog Integration for Legacy Aircraft Single or Dual Installation An analog output interface drives existing indicators, bringing aircraft that were never converted to glass up to current standard without panel modification. The RA-6500 supports single or dual installations for commercial and military fleets on the same interfaces and the same footprint. Situational Awareness Around 5G Networks Adaptable for Next-Gen Aviation Customized RF filtering and Digital Signal Processing maintain consistent altitude data, preventing erratic readings, autopilot disengagements and false terrain warnings. Multi-interface support and flexible installation options suit modern glass cockpits, mission systems and legacy configurations, with the RA-5500 optimized for UAM operations. C-band allocations vary by region, and the guard band to 4.2–4.4 GHz is wider in some jurisdictions than in others. Interference exposure is frequently assessed as a regional condition. Two factors extend it. Regulators continue to release upper mid-band spectrum for mobile networks, narrowing the guard band across an airframe’s service life, and aircraft operate across jurisdictions with differing allocations. Terrain Series altimeters are a current-generation design. Customized RF filtering and Digital Signal Processing are integrated at the receiver rather than applied downstream, maintaining consistent altitude data in RF-dense environments across operating regions. Units meet AD 2023-10-02 and AD 2023-11-07. The final rule on interference-tolerant radar altimeters (Docket FAA-2025-5666) takes effect 29 September 2026. Compliance is required by 30 December 2030 for Part 121 and large Part 129 operators, which includes foreign carriers serving the United States, and by 31 October 2034 for all others. FreeFlight Systems is a named signatory in the rule. Check your aircraft at freeflightsystems.com/aircraft-checker Approvals, certificate numbers and installation contacts are published in the FreeFlight Systems STC library. Retains existing antennas, indicators and cabling. RS-485/422, RS-232, ARINC 429 and ARINC 552A, with popular glass displays or the standalone RAD-45 indicator. Get the full specifications. The Terrain Series datasheet covers technical specifications, model comparison, interface detail and certification. Shape the Skies. NextGen leader. Industry expert. Trusted partner. Get the Datasheet freeflightsystems.com/aircraft-checker [email protected] | +1 254.662.0000 | UK +44 20 3540 1777