Switzerland's H55 is electric aviation's latest downsizer. Electric propulsion system developer cuts nearly half its workforce after a key certification milestone. Monday, June 29, 2026 at 01:41 PM ET Key takeaways: Swiss propulsion system developer H55 is the latest electric aviation firm to scale down amid growing pains for the sector. Per a news release shared with FLYING on Monday, H55 laid off 54 employees following a "comprehensive review" of the business and its activities. According to Aviation Week, which was first to report the cuts, H55 employed 109 people before the move, meaning the company slashed close to half of its workforce. It had originally estimated 80 layoffs. The workforce reduction comes just months after H55 achieved a key certification milestone for its electric propulsion system (EPS), putting it through safety testing observed by the European Union Aviation Safety Agency (EASA). The campaign focused on proving the EPS could weather the most severe failure scenarios, such as thermal runaway battery fires. Per an August news release, H55 was targeting EASA certification of its 104-kilowatt EPS for CS-23 category Level 1 aircraft in 2026, followed by FAA certification in 2027. "The challenge facing our industry is no longer proving that electric propulsion can work," said Andre Borschberg, cofounder and executive chairman of H55, in a statement. "It is helping customers move from development to commercial deployment. Today's decisions ensure that H55 remains focused on the opportunities where our expertise can create the greatest long-term impact." According to the news release, the downsizing is intended to guide H55 toward new opportunities for its EPS in industries such as autonomy and defense. "The range of applications for H55's technologies has expanded significantly," said CEO Rob Solomon in a statement. "Aircraft manufacturers are [sic] propulsion are increasingly seeking certifiable energy-storage, hybrid-electric propulsion, and energy-management solutions." H55 said Switzerland will remain central to its operations. Research and development, testing, and manufacturing activities will take place in the Chandoline business area of Sion, with certification, customer engagement, strategic partnerships, and other key business functions out of Sion Airport (LSGS). At the same time, the company plans to grow its presence in Canada, where it recently opened a battery manufacturing plant. It will use the Montreal location to maintain proximity to customers in the U.S. Among those customers are U.S. flight schools, which could take delivery of the H55-powered Bristell B23 Energic, produced by Czechia's BRM Aero, under the FAA's Modernization of Special Airworthiness Certifications (MOSAIC) rule. The company also has a partnership with CAE to electrify 80 Piper Archer trainers, and its systems power RTX's hybrid-electric flight demonstrator. What is H55? H55 describes itself as the technological spinoff of Solar Impulse, the record-breaking solar-powered aircraft project that Borschberg co-founded. Borschberg was a pilot on the Solar Impulse 2's 2016 circumnavigation of the Earth, the first by a fixed-wing plane using only solar power and zero fuel. The Solar Impulse CEO's new venture specializes in certification-grade electric propulsion systems that are built around commercial lithium cells. The idea is that the EPS could be installed across different airframes through supplemental type certification (STC) programs, rather than being certified for a single model. The company claims it has designed, built, and flown multiple electric aircraft for more than 2,000 hours in total. But that has not translated to the investment required to maintain a 100-strong workforce. H55's flagship EPS comprises an energy storage system that contains battery packs, plus an electric propulsion unit containing the electric motor, inverter, and power electronics. The company holds EASA design organization approval (DOA) and production organization approval (POA), as well as a type certification basis for its 104-kilowatt system. Later, the company plans to introduce a 200-kilowatt EPS for larger CS-23 aircraft in the normal, utility, and commuter categories, as well as even more powerful systems for CS-25 aircraft. H55's first customer application for the 104-kilowatt EPS is planned to be the Bristell B23 Energic. The two-seat, fully electric trainer boasts 70 minutes of flight endurance including reserves and is listed at $500,000. H55 in April delivered its first conforming battery systems to manufacturer BRM Aero, with initial deliveries planned for 2027. The company claims to have more than 100 orders, selling out its first two years of production capacity. The technology is the real deal. Last year, an H55 EPS-equipped B23 completed a four-month, eight-state tour of the U.S. Per H55, it conducted 198 all-electric flights into 25 airports, racking up 63 flight hours. The company estimates a B23 Energic flight hour costs less than $7 compared to around $60 for similar combustion aircraft. A variant of H55's energy storage system also powers RTX's much larger hybrid-electric demonstrator, which is built around a De Havilland Dash 8 and designed to improve fuel efficiency by 30 percent. H55 delivered conforming battery systems for that project earlier in June. In addition, the company is retrofitting CAE's Piper Archers and developing a conversion kit for existing users. It is also converting Harbour Air's fleet of De Havilland Beaver regional commuters. Why it matters. H55's downsizing is symptomatic of broader struggles for the electric aviation sector, which remains in the developmental phase despite more than a decade of investment into some firms. Last month, Dutch hybrid-electric regional aircraft developer Maeve Aerospace - a partner of Delta Air Lines, Skywest, Japan Airlines, and others - went bankrupt, casting doubt on those carriers' sustainability ambitions. This month, France's Aura Aero acquired another French company, VoltAero, that had been developing hybrid-electric business jets. Aura recently secured fresh funding, but other developers have struggled to finance their activities. ZeroAvia, a leader in hybrid aircraft powertrains, has halved its workforce and delayed certification of its commercial ZA600 powertrain in favor of pursuing applications in autonomy and defense. Before that, two German developers of electric air taxis, Lilium and Volocopter, ran out of cash. Volocopter was acquired by the Chinese owner of Diamond Aircraft and has since reemerged, but Lilium's assets were sold. "We won't walk away from existing programs, rather recalibrate so we can work on other types of programs which are emerging on the market," H55 co-founder Gregory Blatt told Aviation Week. The U.S. in particular has bet heavily on electric aviation, with ambitions to become the global leader in the sector. Airlines, airports, and private investors have poured billions into developers of electric air taxis, autonomous drones, and the infrastructure that will support them. Under the current presidential administration, regulating and supporting these new entrants is a core priority for the FAA, which will soon oversee nationwide trials spanning 26 states. Jack is a staff writer covering advanced air mobility, including everything from drones to unmanned aircraft systems to space travel - and a whole lot more. He spent close to two years reporting on drone delivery for FreightWaves, covering the biggest news and developments in the space and connecting with industry executives and experts. Jack is also a basketball aficionado, a frequent traveler and a lover of all things logistics.

Smartflyer and H55 have announced the first delivery of certifiable Adagio battery modules for the SFX1 hybrid-electric aircraft, marking a significant milestone in electric aviation development. The delivery enables Smartflyer's transition from component validation to full system integration for its proof of concept demonstrator programme. The Adagio battery system has completed all regulator-required certification tests, demonstrating readiness for integration across electric and hybrid-electric aircraft applications. Ground testing of the SFX1 is scheduled for summer 2026, with first flight targeted for autumn. H55, a Swiss company specialising in certified electric propulsion systems, has accumulated over 2,000 hours of fully electric flight with zero battery-related incidents. Smartflyer is developing the SFX1 for sustainable pilot training, combining electric propulsion with range extender architecture to reduce emissions and operating costs.