Integration of Hemispherical Resonant Gyroscope Navigation for Urban Air Mobility

Safran Electronics & Defense and Eve Air Mobility are collaborating to integrate advanced inertial navigation systems into electric vertical take-off and landing (eVTOL) aircraft. The project targets urban air mobility applications requiring continuous navigation availability in dense aerial environments.

Technical Challenge and System Integration
Urban air mobility operations require precise positioning and trajectory tracking, particularly when Global Navigation Satellite System (GNSS) signals are degraded, jammed, or obstructed by urban infrastructure. To meet aviation safety requirements, navigation architectures must maintain high signal integrity without reliance on external radio frequency references.

To solve this operational constraint, Eve Air Mobility is incorporating two SkyNaute hybrid inertial navigation systems per aircraft. Safran Electronics & Defense provides the hardware based on its patented Hemispherical Resonant Gyroscope (HRG) Crystal technology. The system provides autonomous position, velocity, and attitude data, combining internal inertial measurements with satellite navigation inputs when available.

Architectural Features and Operation
The HRG Crystal sensor utilizes a vibrating quartz resonator to measure angular rate through the Coriolis force. This design eliminates mechanical moving parts, which reduces mechanical wear, lowers failure rates, and provides high mean time between failures (MTBF). The dual-unit configuration establishes redundant sensor data streams within the flight control architecture, maintaining continuous navigation functionality during single-point sensor failures or GNSS blackouts.

Eve Air Mobility integrates these units into its full-scale eVTOL prototype flight control system, while Safran provides system integration and software calibration support.

Flight Test Validation
The navigation architecture is being evaluated as part of Eve Air Mobility’s flight test campaign at the Embraer facility in Gavião Peixoto, São Paulo State, Brazil. The initial phase included hover and low-speed flight evaluations, recording nearly 2.5 hours of flight time to validate sensor performance and signal stabilization under low-altitude operational conditions.

"Integrating an advanced navigation solution like SkyNaute is essential to maximizing the safety, reliability and performance of our eVTOL," said Johann Bordais, CEO of Eve Air Mobility. "Leveraging Safran’s renowned expertise in inertial navigation, we strengthen our aircraft’s architecture and reinforce our commitment to delivering a robust, certifiable solution for the urban air mobility market."

"With SkyNaute, Safran Electronics & Defense is now leveraging its inertial navigation expertise to serve the next generation of civil aviation," said Benjamin Declety, Head of Avionics Global Business Unit at Safran Electronics & Defense. "We are proud to support Eve Air Mobility in the development of its eVTOL and contribute to the emergence of new urban air mobility solutions."

The ongoing test program aims to verify system performance against civil aviation certification standards for commercial urban air mobility operations.

Edited by Evgeny Churilov, Induportals Media - Adapted by AI.

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