Swiss-based energy storage specialist H55 has delivered production-conforming propulsion battery modules to Pratt & Whitney Canada for integration into the RTX Hybrid-Electric Flight Demonstrator.
The demonstrator is a modified De Havilland Canada Dash 8-100 regional turboprop pairing a Pratt & Whitney Canada thermal engine with a 1MW electric motor from Collins Aerospace. H55’s 200kWh battery system provides electrical power for the motor, and the program targets a 30% improvement in fuel efficiency over current regional turboprops.
The delivery follows the successful full-power ground test of the integrated propulsion system and batteries in 2025, and marks H55’s transition from technology development to industrial-scale manufacturing for the battery modules.
H55 has completed the industry’s first regulator-required propulsion battery certification testing for electric aircraft, with the certification evidence now serving as a production baseline for the RTX program. The company has accumulated more than 2,000 flight hours across multiple aircraft programs with zero battery-related incidents.
H55 was established from the technological legacy of the Solar Impulse project, which completed the first solar-powered circumnavigation of the globe. The company’s battery architecture was developed to meet the certification demands of electric and hybrid-electric propulsion, building on technology H55 has already deployed in flight on smaller all-electric aircraft.
Sébastien Demont, H55 co-founder and chief technology officer said, “Aircraft manufacturers today require certification-grade safety architecture, industrialized manufacturing, operational reliability and scalable systems integration. Delivering production-conforming modules into the RTX Hybrid-Electric Flight Demonstrator validates H55’s ability to meet those requirements at an industrial scale and marks an important step in bringing our certification-grade energy storage technologies to a broader range of commercial aerospace applications.”
The demonstrator program is part funded by the Canadian government. H55 has received investment from RTX Ventures, the company’s venture capital arm, and AeroTEC will support flight testing of the experimental aircraft from its facility in Moses Lake, Washington.
Jean Thomassin, executive director for new product and service introduction at Pratt & Whitney Canada said, “Hybrid-electric propulsion represents an important pathway for improving fuel efficiency and performance for a wide range of future aircraft platforms. H55’s ability to deliver aviation-grade battery systems within a rigorous certification and production framework plays a crucial role in demonstrating hybrid-electric technology in flight.”
