5 June 2025
VoltAero has unveiled its new aircraft powertrain, the HPU 210. The French tech startup says it brings hybrid-electric propulsion to propeller-driven aircraft in the homebuilt, kit-built and very light aircraft categories.
It is on display for the first time on VoltAero’s stand at France Air Expo which opened 5 June in Lyon, France.
The HPU 210 hybrid power unit (HPU) combines a high-performance thermal engine with an advanced electric motor to boost power by 40 percent.
Jean Botti, VoltAero’s CEO & Chief Technology Officer and formerly of Airbus, explained, “With the HPU 210, a new category of airplanes will benefit from the patented, proven hybrid propulsion technology pioneered by VoltAero for our Cassio family of regional aircraft, which are now advancing into their pre-production phase.
“We’ve validated our hybrid propulsion architecture on our in-house Cassio S flying testbed, which has logged more than 185 flight hours and flown approximately 25,000 kilometres in a full range of operating conditions.”
Kawasaki’s motorcycle engines are being reengineered for aero applications and were shown at AERO Friedrichshafen in April. Photo: FLYER
The HPU 210 is equipped with Kawasaki’s H2SX thermal engine which provides maximum power of 150kW (about 203hp), along with a 60kW electric motor.
In typical operation, the thermal engine delivers baseline propulsive power, while the electric motor kicks in during high-power demand situations, resulting in shorter take-off distances, enhanced obstacle clearance and increased cruise speeds.
The supercharged H2SX is derived from Kawasaki’s iconic Ninja H2 SX sport motorcycle It has typical Japanese superbike engine layout with four cylinders in-line engine, electronic fuel injection and has an estimated TBO (time between overhaul) of 1,500 hours.
In VoltAero’s HPU 210 configuration, the hybrid-electric propulsion unit is controlled by a single throttle with the thermal engine generating the power from zero to 70 percent. The additional boost power is delivered by the electric motor and its battery.
VoltAero claims fuel consumption as low as 38 litres per hour at cruise settings. The HPU 210 runs on avgas, biofuel (such as the E85 ethanol-gasoline blend) and standard unleaded automotive fuel.
VoltAero’s new powertrain
The HPU 210 will be supplied by VoltAero as a turnkey solution, with the kit including a complete powertrain unit composed of the thermal engine, electric motor, gearbox and electronic control unit. A bench test campaign with the HPU 210 has been performed at VoltAero’s partner, AKIRA, in southern France.
VoltAero will initiate HPU 210 production at the company’s purpose-built Rochefort Airport industrial facility in France’s Nouvelle-Aquitaine Region, where its Cassio family of regional aircraft also will be assembled. Deliveries of HPU 210s are targeted to begin late 2026.
