H55 today announced the successful completion of its System Safety Function Verification Testing, marking a key milestone in the validation of its integrated Energy Storage System (ESS) and its progress toward certification.

In the final stages toward certification, H55 successfully validated its Energy Storage System (ESS) in a fully integrated configuration, bringing together all critical subsystems into a complete and operational architecture. The test setup included Battery Modules (BMs), Battery Management Units (BMUs), Energy Flow Counter (EFC), Protection and Power Distribution Unit (PPDU) and the Charge Control Unit (CCU).

The campaign focused on validating system-level performance, communication integrity, and—critically—safety functionality under real operating conditions. The results confirmed robust and reliable coordination across all subsystems, ensuring stable and predictable system behavior across a range of scenarios.

A key outcome of the campaign was the successful verification of critical safety functions at system level, including the automatic and controlled disconnection of power under predefined fault or off-nominal conditions—an essential capability for safe operation in aviation environments.

Beyond hardware validation, this milestone represents a significant step in de-risking H55’s software verification and certification roadmap, with all system safety functions performing as expected within an integrated architecture.

“This milestone represents a major step in de-risking both our technology and our certification roadmap,” said Anthony D’Ambrisi, Head of H55’s Design Organization. “By validating system-level safety functions in a fully integrated architecture, we are demonstrating readiness for certification—not just at component level, but as a complete system. This is an important step toward industrialization and large-scale deployment.”

Unlike many emerging players developing systems in isolation, H55’s ESS has been engineered in alignment with certification requirements from the outset, in close coordination with aviation authorities including EASA. The system is developed to aerospace-grade standards, well beyond experimental or “permit-to-fly” approaches.

With more than a decade of experience in electric aviation, H55’s safety philosophy goes beyond managing failure—focusing instead on detecting, controlling, and mitigating risks before they escalate. This approach enables a higher level of system reliability and is fundamental to achieving certification in demanding aviation environments.

The successful completion of this campaign marks a critical step in bringing H55’s technology from validation to deployment. With active programs underway and growing demand for certified electric propulsion solutions, H55 is positioned to support aircraft manufacturers and operators in the transition toward electrified flight.

As the aviation industry accelerates toward decarbonization, H55’s integrated and certifiable energy storage systems are enabling a new generation of electric aircraft—designed not just to fly, but to scale.