Flight Powered by Excellium Racing 100 SAF

VoltAero, the French aerospace company founded by former Airbus chief technical officer Didier Esteyne, has completed the first flight of an aircraft powered by the proprietary electric-hybrid powerplant by which the company’s inchoate Cassio 330 Short Take-off and Landing (STOL) aircraft will presently be motivated aloft.

Subject flight was undertaken at VoltAero’s development facility at Royan, France, and conducted by VoltAero’s Cassio S testbed airplane. Moreover, the enterprise made use of Excellium Racing 100, a Sustainable Aviation Fuel (SAF) synthesized by global multi-energy concern TotalEnergies from biomass waste-products deriving of French vineyards.

VoltAero’s CEO and chief technology officer Jean Botti stated: “Based on initial results, we calculated a truly impressive CO2 reduction of approximately eighty-percent while operating the Cassio powertrain in its electric-hybrid mode and with the internal combustion engine fueled by TotalEnergies’ Excellium Racing 100. 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 maintained VoltAero was proud to have been associated with TotalEnergies in the test-flight, which he contended occasioned advancement toward biofuel’s eventual use in general aviation.

Excellium Racing 100 fuel has, since 2022,  been used in automobile competitions, including the storied 24 Hours of Le Mans endurance racing event. The fuel is made, in part, from winemaking waste, and, over a given engine’s life-cycle, facilitates reductions in CO2 emissions of up to 65-percent—so say the stuff’s makers.

TotalEnergies Aviation president Joël Navaron set forth: “This demonstration flight is part of our commitment to support players in the aviation sector for their decarbonization objectives. 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.”

The first Cassio 330 prototype, somewhat unimaginatively dubbed no. 1, is slated to undertake its maiden flight in late 2023. The test aircraft will be powered by a four-cylinder Kawasaki reciprocating engine and serve to validate airframe performance, robustness, and aerodynamic efficiency.

Prototype no. 1 will be followed, predictably, by no. 2, which is to make its inaugural flight in 2024’s second quarter. Cassio 330 prototype no. 2—which is to be powered by VoltAero’s full hybrid propulsion scheme—will be evaluated by EASA for type certification.

VoltAero’s hybrid propulsion scheme comprises a 221-horsepower, four-cylinder Kawasaki reciprocating engine and a 241-horsepower Safran ENGINeUSTM smart electric motor. The latter powerplant drives a single, two-meter-diameter, aft-facing, centerline-thrusting pusher-propeller.

The Cassio’s electrical system provides power during taxi, takeoff, primary flight, and landing. The Kawasaki internal-combustion engine recharges the aircraft’s batteries while in-flight and serves as a backup in the event of electrical malfunction. 

The Cassio 330 is a single-pilot, four-passenger, Short Take-off and Landing (STOL) aircraft, the numerical designation of which pertains to the machine’s combined hybrid-electric power-rating of—more or less—330-kilowatts.

In all, VoltAero plans to produce three iterations of its Cassio design, each sharing a high degree of modularity and commonality. Certification of the Cassio 330 will be followed by the releases and certifications of the six-seat Cassio 480, with a combined electric-hybrid power output of (you guessed it) 480-kilowatts, and the 10-12-seat, Cassio 660, with a combined electric-hybrid power output of …

VoltAero’s design for the Cassio aircraft family is based on a sleek, aerodynamically-optimized fuselage, a forward canard, and an aft-set wing with twin booms that support a high-set horizontal tail—after the fashion of a radically modernized, Cessna 337 Skymaster.

VoltAero has selected AKIRA Technologies to facilitate the integration and validation of Cassio’s hybrid propulsion unit. A fellow-French concern, AKIRA Technologies—which formerly specialized in the design and production of energy conversion systems and test benches—has been tasked with designing and developing the Cassio hybrid propulsion unit’s gearbox, integrating subject gearbox with the extant Kawasaki/Safran architecture, and ground-testing the lot.

The no. 2 Cassio 330 prototype will be kitted out with an Avidyne EFIS suite featuring new-generation Quantum 14-inch 4K displays optimized for single-pilot operation. VoltAero and U.S.-based Avidyne will co-develop means by which to tailor the avionics suite to accurately display the operation-salient parameters of Cassio’s hybrid propulsion unit.

VoltAero will assemble the Cassio aircraft at a purpose-built facility on the Rochefort Charente-Maritime Airport (LRH) in France’s southwestern Nouvelle-Aquitaine region.

FMI: www.voltaero.aero