The battery system validated by the EASA of the Swiss electric propulsion company makes it possible to advance the hybrid-electric demonstrator project whose objective is to improve the energy efficiency of regional aircraft by up to 30%
/PRNewswire/ — H55 today announced the continued development of the 200 kWh energy storage system (ESS) for the RTX hybrid-electric flight demonstrator, since the project reached the milestone of its first full-power system test conducted in June 2025.
RTX hybrid-electric flight demonstrator
H55 Battery Module
This demonstrator, led by Pratt & Whitney Canada and Collins Aerospace (subsidiaries of RTX), intends to demonstrate an improvement of up to 30% in the fuel efficiency of regional aircraft thanks to a hybrid-electric propulsion architecture combining an advanced thermal engine, an electric motor with a power of 1 megawatt and the H55 battery system.
Pratt & Whitney Canada designed the H55 battery architecture and safety mechanisms to serve as the certifiable basis for the demonstrator’s propulsion system. The H55 energy storage system, validated through numerous flight operations, provided the compliance and safety foundation that allowed the program to advance rapidly.
Commenting on the partnership between H55 and Pratt & Whitney Canada, Rob Solomon, CEO of H55, said: “There is a notable difference between being selected as a component supplier and being chosen as a basis for certification. Pratt & Whitney Canada didn’t just buy our batteries: the company based its prototype’s compliance baseline on an architecture that H55 has already used for over 2,000 incident-free flight hours and which has been validated in campaigns tests carried out by the EASA. This is what eight years of disciplined certification work allows: when a regional aircraft-scale program needs to move forward quickly, it turns to the system that has already proven itself. This milestone – the first full-power ground test of a hybrid-electric propulsion system on this scale – is the work of the entire team. »
The H55 ESS is designed specifically to meet the requirements of aeronautical certification. The system is designed to be lightweight, modular to enable flexible integration on board aircraft and optimal weight distribution, and is based on a cellular architecture that has already been the subject of test campaigns conducted by the European Aviation Safety Agency.
This technology builds on H55’s broader experience in developing electric propulsion systems for aviation. The company has conducted extensive safety validation campaigns for its battery modules, an essential step for the certification of next-generation electric propulsion architectures.
Sébastien Demont, CTO and co-founder of the company, explains the importance of this development for H55: “This integration step represents a watershed moment for H55 and for electric aviation as a whole. The certifiable battery architecture we developed for the CS23 aircraft has proven its scalability: the same safety philosophy at the cell level, the same engineering discipline, now powers a battery system at the heart of a CS25 hybrid-electric demonstrator at the alongside Pratt & Whitney Canada. We are not adapting a concept, we are scaling a proven and validated platform. That is developing a certifiable technology from its conception. »
H55 was born from the pioneering SolarImpulse project, which demonstrated that electric propulsion could enable long duration flights. Building on this heritage, H55 has since developed and flown multiple electric aircraft platforms, accumulating operational experience that continues to inform the development of next generation propulsion systems.
With the RTX hybrid-electric flight demonstrator now entering the phase of onboard integration and flight testing on a modified De Havilland Canada Dash 8-100, H55’s battery technology will enable validation of hybrid-electric propulsion at the regional aircraft scale.
The program also represents an important step in extending H55 technology from smaller electric aircraft platforms to the Part-25/CS-25 category of regional aircraft. By supporting a hybrid-electric propulsion system at regional aircraft scale, this demonstrator allows H55 to further validate its energy storage system architecture in an environment representative of future commercial applications.
Entry into the regional aircraft category represents a significant expansion of the accessible market for H55 propulsion technology, as hybrid-electric architectures are increasingly being considered for next-generation regional aircraft platforms.
As aircraft manufacturers explore hybrid-electric propulsion to improve efficiency and reduce emissions, scalable battery systems capable of meeting aviation certification requirements are expected to play a central role in the architecture of future regional aircraft.
Rob Solomon added: “Programs like this allow us to demonstrate that the same certifiable battery architecture developed for small aircraft can be adapted to the regional aviation market. This transition marks a decisive step in unlocking the commercial potential of electric propulsion. »
This important milestone demonstrates the growing maturity of electric propulsion technologies and their role in establishing more efficient and less polluting air transport. As hybrid-electric aircraft enter service, energy storage systems will also become an essential part of the aircraft lifecycle, creating long-term opportunities for certified propulsion technology providers.
About H55
H55 is a Swiss company specializing in certified electric propulsion and energy storage systems for aviation. The company promotes the development of electric aviation by transforming commercial lithium batteries into aviation-friendly energy storage systems that are approved by regulators, covered by insurers and which OEMs can repeatedly deploy as a certified propulsion platform under various aviation programs. This is possible through independent cell characterization, rigorous selection entrants, redundant security architectures and regulator-aligned testing, designed based on worst-case failure scenarios.
Built on the technological heritage of the Solar Impulse program, H55 draws on more than two decades of practical experience in electric aviation. The company has designed, built and flown several electric aircraft and has accumulated more than 2,000 hours of fully electric flight time without any battery incidents, giving it the operational experience necessary to successfully complete certification programs, not just comply with them.
H55 benefits from a strong and experienced management team that combines deep expertise in technology business development with hands-on operational execution. Together, these capabilities ensure a reliable transition from certified design to repeatable mass manufacturing. H55’s platform-based approach, in which certification evidence combines across programs, reduces adoption risk while facilitating the deployment of electric and hybrid-electric aircraft in a capital-efficient manner.
Press relations
Axelle Krummenacher
+41 79 464 22 60
[emailprotected] www.h55.ch
H55 SA
Routedel’Aéroport10 1950 Sion
Suisse
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