In an aviation industry first, VoltAero has flown the proprietary electric-hybrid powertrain for its Cassio family of aircraft with 100% sustainable fuel provided by TotalEnergies.

Conducted from VoltAero's development facility at Royan, France, the milestone flight utilized the hybrid powertrain's electric mode and its internal combustion engine – which was fueled by TotalEnergies' Excellium Racing 100, made from bioethanol produced from waste that originates in French vineyards.

This milestone demonstration was performed with VoltAero's Cassio S testbed airplane, operated by the company to validate its electric-hybrid powertrain and the application of sustainable fuels, thereby de-risking airworthiness certification for upcoming production versions of the Cassio aircraft family.

“Based on initial results, we calculated a truly impressive CO2 reduction of approximately 80 percent while operating the Cassio powertrain in its electric-hybrid mode and with the internal combustion engine fueled by TotalEnergies' Excellium Racing 100,” said Jean Botti, VoltAero's CEO and Chief Technology Officer. “It underscores the opportunity for production Cassio aircraft to represent a major step closer to aviation's decarbonization goals by replacing standard Avgas 100 high-octane fuel for aviation piston engines.”

Botti added that VoltAero is proud to have been associated with TotalEnergies in this achievement, which marks an advancement toward the future use of biofuel in general aviation – and which complements the ongoing introduction of sustainable aviation fuel (SAF).

Excellium Racing 100 fuel has been used since 2022 in certain automobile competitions, including the famous 24 Hours of Le Mans endurance sports car race. It is made from winemaking waste, and allows a reduction in CO2 emissions of at least 65% over its entire life cycle when compared with the fossil fuel equivalent.

“This demonstration flight is part of our commitment to support players in the aviation sector for their decarbonization objectives,” explained Joël Navaron, the President of TotalEnergies Aviation. “More broadly, it demonstrates our desire to continue our research and development efforts to offer an alternative to aviation gasoline containing lead, thereby meeting the challenges of general aviation's decarbonization. We already have initiated several actions – such as the installation of several electric charging stations for general aviation aircraft, and the launch of a pilot program aimed at offering SP98-type fuel for compatible aircraft.”

VoltAero's Cassio family will be a highly capable and reliable aircraft product line for regional commercial operators, air taxi/charter companies, private owners, as well as in utility-category service for cargo, postal delivery and medical evacuation (Medevac) applications.

By integrating VoltAero's patented electric-hybrid propulsion system into the purpose-designed airframe, Cassio will deliver an order of magnitude higher performance as compared to the current competition, and provide significantly lower operational costs.

The VoltAero propulsion concept is unique: Cassio aircraft will utilize an electric motor in the aft fuselage-mounted hybrid propulsion unit for all-electric power during taxi, takeoff, primary flight (if the distance traveled is less than 150 km.), and landing. The hybrid feature – with an internal combustion engine – comes into play as a range extender, recharging the batteries while in flight. Additionally, this hybrid element serves as a backup in the event of a problem with the electric propulsion, ensuring true fail-safe functionality.

VoltAero's first production aircraft will be the Cassio 330, with a four/five-seat interior configuration and operating on a combined electric-hybrid propulsion power of 330 kilowatts. It is to be followed by the six-seat Cassio 480 with a combined electric-hybrid propulsion power of 480 kilowatts, and the Cassio 600 – sized at a 10/12-seat capacity with electric-hybrid propulsion power of 600 kilowatts.

* Excellium Racing 100 is certified as a 100% sustainable product according to the mass balance system applied by a voluntary certification organization approved by the European Union.