France has a long, rich tradition of aerospace innovation and manufacturing, so it should come as no surprise that a handful of French startups are playing a prominent role in efforts to decarbonize aviation with a new generation of clean-sheet aircraft designs.
One of them is VoltAero, a firm based out of Western France that is developing a family of hybrid-electric aircraft it calls ‘the Cassio’.
There will be three versions of VoltAero’s design, starting with the 5-seater Cassio 330, with ‘330’ being a reference to its 330 kW powertrain.
Next, and a tad larger, comes the six-seater Cassio 480, powered by a 480 kW engine, and, finally, the largest of the trio, the Cassio 600, which will seat 10 to 12 and will be powered by – you guessed it – a 600 kW engine.
Of these three models, the Cassio 330 is expected to be the first certified.
The VoltAero Cassio 330 will allow for full-electric flight on distances of up to 200 km, although range can be increased to up to 1,200 km when using hybrid propulsion, which combines both thermal and electric engines.
Perhaps one of the most eye-catching aspects of the Cassio family of aircraft is its unusual, sleek-looking design.
This is mainly because they are built with what is called a ‘tri-surface configuration’, with tail, rear-mounted wings and the frontal stabilizers fitted at different heights.
VoltAero underlines how this approach can deliver some aerodynamic benefits, as well as facilitating the handling of the aircraft and the achievement of faster cruising speeds. Access to the cabin and cockpit should be easier too since the central part of the fuselage is free of any protruding elements.
In the summer of 2023, VoltAero showcased a real-size mockup of the Cassio 330 both at the Paris Air Show and at EAA AirVenture Oshkosh in the US.
Although not the final aircraft, the mockup was realistic enough to provide a real sense of what flying on the Cassio might be like.
One factor that stands out is that, despite its relatively small size, it has a fairly spacious cabin. No wonder that, in addition to the regular passenger configuration, VoltAero is also pitching versions for the cargo and medevac markets, including one specifically for wheelchair users.
The first Cassio 330 is expected to fly before the end of 2023, although at first it will do so using a Kawasaki Motors’ four-cylinder thermal engine.
However, the Japanese firm is already at work on a much larger six-cylinder engine to equip future Cassio aircraft. Both the four and six-piston engines should eventually be capable of running on hydrogen too.
As the testing program progresses, the Cassio 330 should also be able to use the Safran Electrical & Power ENGINeUSTM 100 electric engine.
In the meantime, VoltAero has been testing its technology on a retrofitted Cessna 337 Skymaster, which has flown more than 10,000 km to date.
VoltAero is also working on its industrial plan, with the opening of a factory with three assembly lines, one for each version of the Cassio, adjacent to Rochefort-Charente-Maritime airport (RCO) in Western France. VoltAero is looking to employ around 150 people at this greenfield facility, which should come on stream by the summer of 2024.