Smartflyer and H55 Advance Electric Aviation with First Delivery of Certifiable Battery Modules for the SFX1 Aircraft

SION, Switzerland and SELZACH, Switzerland, April 20, 2026 /PRNewswire/ -- Smartflyer announces the successful delivery of the first batch of Adagio battery modules from H55, marking not only a key milestone in the development of the Smartflyer SFX1 aircraft, but also a significant step in the industrialisation and commercial deployment of H55's certified electric propulsion technologies.

For Smartflyer, the delivery represents a critical step forward in the SFX1 Proof of Concept Demonstrator program, enabling the transition from component-level validation to full system integration and testing. For H55, it marks the continued integration of its certification-ready battery systems into active aircraft programs, reinforcing its position as a provider of scalable, commercially deployable electric propulsion solutions.

The newly delivered Adagio battery modules will be integrated into the SFX1 Aircraft as part of the next phase of development. This includes comprehensive system-level validation covering propulsion architecture, energy management, and other critical aircraft systems, in preparation for the upcoming ground test campaign.

At the same time, this milestone reflects the maturity and readiness of H55's product portfolio. The Adagio battery system has successfully completed all regulator-required certification tests, demonstrating its safety, reliability, and suitability for integration across a growing range of electric and hybrid-electric aircraft applications.

The SFX1 program is now entering an advanced stage of development, with integration activities intensifying across multiple workstreams. Ongoing efforts focus on coordinating installation, calibration, and test readiness to ensure a smooth transition into the next milestones. Ground testing of the SFX1 is planned for this summer, with the first flight targeted for autumn, keeping the program aligned with its development roadmap.

"Receiving the first Adagio battery modules from H55 is a major milestone for Smartflyer and a key enabler for the next phase of our development program. It also highlights the strength of our collaboration with a partner whose technology is not only innovative but ready for real-world application. Together, we are taking concrete steps toward bringing efficient and sustainable aviation solutions to market," said Rolf Stuber, CEO of Smartflyer.

"This delivery marks an important step in bringing H55's certified battery and propulsion solutions into operational aircraft programs. Our collaboration with Smartflyer illustrates how our technology, spanning both electric and hybrid-electric configurations, is moving from development into commercial application, enabling aircraft manufacturers to accelerate their path to flight. We are proud to support the SFX1 program and contribute to the broader adoption of electric and hybrid-electric aviation," said Rob Solomon, Chief Executive Officer of H55.

About H55

H55 is a Swiss-based company specializing in certified electric propulsion and certification-grade energy storage systems for aviation. The company enables electric aviation to scale by transforming commercial lithium cells into aviation-safe Energy Storage Systems that regulators approve, insurers underwrite, and OEMs can deploy repeatedly as a certified propulsion platform across aircraft programs. This is achieved through independent cell characterization, rigorous incoming screening, redundant safety architectures, and regulator-aligned testing designed around worst-case failure scenarios.

Founded as the technological legacy of the Solar Impulse program, H55 builds on more than two decades of hands-on electric aviation experience. The company has designed, built, and flown multiple electric aircraft and has accumulated more than 2,000 hours of fully electric flight with zero battery-related incidents—providing the operational depth required to execute certification-grade programs, not merely comply with them.

H55 benefits from a strong and experienced leadership team that combines deep expertise in scaling technology companies with hands-on operational execution. Together, these capabilities support a reliable transition from certified design to repeatable series manufacturing. H55's platform-based approach, in which certification evidence compounds across programs, reduces adoption risk while facilitating the capital-efficient deployment of electric and hybrid-electric aircraft.

About Smartflyer

Smartflyer is a Switzerland-based aviation company developing the SFX1, an innovative hybrid-electric aircraft designed for sustainable pilot training. By combining advanced electric propulsion with a range extender architecture, Smartflyer aims to significantly reduce emissions and operating costs while maintaining operational flexibility. The SFX1 program is currently progressing through its Proof of Concept phase, with a strong focus on certification-ready technologies and scalable solutions.

Contacts

H55 : 
Axelle Krummenacher - axelle.krummenacher@h55.ch - +41 79 464 2260

Smartflyer : 
Dominik Heiri - dominik.heiri@smartflyer.ch - +41 79 946 00 60          

H55 SA
Route de l'Aéroport 10 1950 Sion
Switzerland
www.h55.ch

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