TERRAIN SERIES RA-4500 MK II Low-Altitude Precision for Rotorcraft Operations Reliable AGL data through hover, terrain transitions and low-level operations, in a retrofit-ready design that minimizes installation impact and downtime. Empowering safer flights and faster installs, the RA-4500 MK II delivers accuracy and reliability with seamless integration and minimal downtime. It replaces RA-4000 and RA-4500 installations and legacy altimeters from other manufacturers, using existing antennas and cabling. Retrofittable Across Platforms Proven Across Mission Profiles Engineered for digital integration with support for legacy antennas and cabling, enabling smooth retrofits into existing airframes without extensive rework. Helicopter SAR and EMS, low-level tactical military operations and UAM in urban environments, with consistent performance in reflective and cluttered RF zones. Situational Awareness Around 5G Networks Global Compliance and Airspace-Ready Customized RF filtering and Digital Signal Processing maintain consistent altitude data, preventing erratic readings, autopilot disengagements and false terrain warnings. TSO-C87a, DO-160G and DO-178C Level B. STC documentation, compliance guidance and engineering support are available for installation. 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 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