The tech onboard VoltAero’s Cassio electric-hybrid aircraft

The Cassio 330 prototype on display at the 2023 Paris Airshow. Credit: Cassio

French startup VoltAero has unveiled its first Cassio 330 electric-hybrid aircraft prototype, following the Cassio family’s announcement in May 2020.

The aircraft manufacturer has developed a proprietary hybrid propulsion system that combines thermal and electric power for “maximum flight safety and efficiency”, according to VoltAero.

The Cassio 330 prototype, presented during the Paris Air Show, is set to perform its maiden flight in late 2023. This prototype will validate the overall airframe configuration and aerodynamics of VoltAero’s design.

The aircraft will be powered by a four-cylinder thermal engine derived from Kawasaki Motors’ motorcycle engines.

“Today marks a true milestone for electric aviation, as VoltAero delivers on its promise to take an all-new approach for quiet, efficient and eco-friendly transportation that is based on a hybrid design combining thermal and electric propulsion for maximum flight safety,” Jean Botti, VoltAero’s CEO and CTO said alongside the Paris Air Show unveiling.

“I want to thank my VoltAero team for its dedication and tireless work in reaching this historic moment, as well as express my appreciation to our suppliers and partners for their commitment to Cassio.”

VoltAero’s Cassio family comprises three different models: the Cassio 330, Cassio 480, and Cassio 600. The aircraft will be assembled in a purpose-built facility at the Rochefort Charente-Maritime Airport in France’s Nouvelle-Aquitaine region. 

The 330 kilowatt (Kw)-power Cassio 330 is designed as a four/five-seater aircraft, offering “a perfect balance” between passenger capacity and operational efficiency according to VoltAero.

The Cassio 480, with a combined electric-hybrid propulsion power of 480 kilowatts, accommodates up to six passengers, making it ideal for regional travel and air taxi services. For larger groups, the Cassio 600 can seat 10 to 12 passengers and features an increased electric-hybrid propulsion power of 600Kw.

VoltAero’s Cassio family uses a unique hybrid propulsion system. During taxi, takeoff, primary flight (for distances less than 150km), and landing, the aircraft relies solely on the electric motor mounted in the aft fuselage.

This all-electric power mode allows for quiet and eco-friendly operation. The hybrid feature, combining an internal combustion engine with the electric motor, acts as a range extender, recharging the batteries while in flight. It also serves as a fail-safe backup in case of any issues with the electric propulsion system.

The second Cassio 330’s maiden flight in the second quarter of 2024. This aircraft will be used for the airworthiness certification programme.

VoltAero says the second model will be equipped with VoltAero’s full-up hybrid propulsion unit – composed of the four-cylinder Kawasaki Motors thermal engine (with a peak power rating of 165kW) and a Safran smart electric motor (with a peak power rating of 180kW).

The French aircraft manufacturer has chosen AKIRA Technologies, a French company specialising in energy conversion systems, for the integration and validation of the Cassio 330.

AKIRA will be responsible for designing and developing the hybrid propulsion gearbox, as well as the mechanical integration and ground testing of the unit. Additionally, AKIRA will test and adapt the Kawasaki engine and the Safran electric motor, ensuring seamless integration and optimal performance of the hybrid propulsion system.

The Cassio 330 prototype will feature a full glass cockpit with avionics provided by US-based avionics manufacturer Avidyne.

Avidyne will develop a customised avionics suite, including new-generation Quantum 14-inch displays, specifically designed for single-pilot operation.

The cockpit panel configuration will highlight a dual Primary Flight Display/Multifunction Display layout with 4K resolution. According to VoltAero, this avionics system will “enhance situational awareness” and “improve the overall flying experience”.

VoltAero says it is exploring sustainable fuel options for the Cassio’s hybrid propulsion unit.

Biofuels and hydrogen are among the potential alternatives being considered. VoltAero’s Cassio testbed aircraft is currently undergoing flight validations using biofuel, demonstrating the company’s dedication to reducing environmental impact.

As part of its exhibit at the Paris Air Show, VoltAero is showcasing a Kawasaki Motors thermal engine that operates with liquid hydrogen.

VoltAero says this technology will be incorporated into future Cassio 330 aircraft, further enhancing their sustainability and contributing to the industry’s decarbonisation efforts.

The Cassio aircraft family is positioned to cater to regional commercial operators, air taxi/charter companies, and private owners, as well as cargo transportation, postal delivery, and medical evacuation (Medevac) operations.