VoltAero Hybrid-Electric Demonstrator Makes Channel Crossing


On Monday (Sept. 13), VoltAero’s Cassio 1 demonstrator hybrid-electric aircraft made its first English Channel crossing, and is participating in this week’s ACE21 Air Charter Expo at London Biggin Hill Airport. VoltAero CEO and Chief Technology Officer Jean Botti is participating in the expo’s Green Charter 2021 panel discussion.

The Cassio 1 flight originated at Calais in northern France. VoltAero’s facility is 500 miles south in Medis, southern France. The aircraft made a stop at Cranfield University in Bedfordshire, U.K., for inspection by engineering students and faculty before continuing on to Biggin Hill for the expo.

In 2015, VoltAero’s E-Fan aircraft, developed as part of an Airbus-led program, made what the company says is the “first end-to-end English Channel crossing with an electric airplane.” While the E-Fan’s batteries provided 60 kilowatts for its two all-electric motors, the Cassio 1 is powered by VoltAero’s 600-kilowatt electric-hybrid “power module,” which combines electric power with an internal combustion engine. “In providing dual sources of energy, the electric-hybrid power module is reported to provide highly safe and efficient operations by using one source of power—electrical or mechanical, or both—depending on the flight scenario,” according to VoltAero. The idea is to take off “nearly silently” on electric power, then use the internal combustion engine for en route cruise while charging the batteries—and serving as backup power.

VoltAero anticipates its four-seat Cassio 330 will be its first production aircraft with 330 kilowatts of hybrid-electric power. Service entry is targeted for the second half of 2023. The follow-on six-seat and 10-seat Cassio 480 and 600 (respectively) are expected to generate 480 and 600 kilowatts.

Mark Phelps is a senior editor at AVweb. He is an instrument rated private pilot and former owner of a Grumman American AA1B and a V-tail Bonanza.

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  1. “In other news….—42 years ago, in 1979—the very same channel was crossed by the human powered Gossamer Albatross—a feat that has never been duplicated or again attempted….”

    Doing it again in an “electric airplane”(with a piston engine providing power and backup) is not in the same category.

    HARDLY a “STOP THE PRESSES!” “Press release.”

    Slow news day?

  2. If you must go electric, this is how it can work. I always thought the Skymaster had more potential.
    I’m an electrical engineer. I know and hate batteries, they are based on corrosion. Lithium was something of a miracle, hard to top. We can only hope.

    • Lithium is a wonderful chemical if you don’t mind it’s rather nasty habits. It wants to burn in contact with air, tries to explode in contact with water and causes severe chemical burns in contact with human skin. Breathing the vapors it emits can cause severe and permanent lung damage. Other than that, it’s great stuff! You are wise to dislike batteries. Seriously though, it is the most reactive metal in the periodic chart, so it has been the material of choice for vehicle batteries. The bad news is that lighium’s potential has pretty well reached its peak, so if people can find a better material for high capacity batteries, it will have to be something like solid state or carbon based capacitors. Nature has provided us a material that is extremely energy dense – called crude oil. Unfortunately it has that carbon emissions problem. No free lunch…

  3. As an endurance cyclist I have much respect for the Gossamer Albatross. Both the engineering and the athleticism.

    As far as Bleriot goes, I also have much respect for his engineering and piloting. The Wrights invented the airplane, but Bleriot invented the airplane as we know it.

    This antique Cessna breaks no new ground such as the two mentioned above have.

    Electric cars can work in a certain limited number of circumstances, because they do not need to levitate their immense weight. Battery powered (mainstream) flight cannot work because wishful thinking does not negate the laws of physics.

    i.e. being too fat to fly.

  4. Back in 1979, Bryan Allen of Tulare CA flew across the English Channel in Paul MacCready’s human powered, 75 lb. Gossamer Albatross ultra ultra light airplane. While it was an amazing achievement, it has never been repeated and has contributed little to the progress in aviation, although it did win the $220,000 Kremer prize. The feat was featured in the November 1979 issue of National Geographic. So happens that two young guys from the same small town were featured in the same Nat Geo issue, albeit for two very different achievements. However, I don’t think this story will make Nat Geo, win a cash prize, nor with it contribute much to progress in aviation. Nor will it be remembered 42 years from now.

  5. Frankly, it is refreshing to see an old airplane be used as a proof of concept aircraft for emerging technology. If there was ever a time to call this airplane a “mixmaster”, it is now.

    No swoopy artist rendering displayed via virtual reality video. Instead, a proven airplane modified to use electric power, refine the hybrid engineering they currently have, and back up the investment with a good old air-cooled, avgas ( lead included) burning reliable, proven powerplant, making sure that if all else fails over the Channel or anywhere else, it will most like make an uneventful landing. And with that common sense back up in a stout, well proven airplane, whatever electric development that they are trying to mature, most likely will not end up as a smoking hole, or in the case of the Channel crossing…fish food or the start of a new reef…should something not go as planned.

    At least they are actually flying something a reasonable distance actually accomplishing something by gaining useful information with out worrying about flying qualities of an unproven airframe. The goal is maturing an alternative aviation powerplant for a useful, practical distance. Once that is satisfied, stuff it into a new airframe if necessary. Who knows, maybe a refined twin version of this concept could be used to inject new life into the old Skymaster…rightfully and proudly earning the nick-name “MixMaster”.

  6. I have been experimenting with Solar Panels and LiFePO4 batteries for a year now, kind of preparing for when the Stuff Hits The Fan. I like LiFePO4 batteries, and if done correctly (with a failsafe BMS’s, fuses, robust (that is, heavy) cabling, etc.) they offer a lot of potential. (No pun intended. But I’ll take it.)

    But I was explaining to a Lefty recently why an Electric Air Transport isn’t feasible. At least, not at this time. (Perhaps when micro-nuclear reactors become commonplace. Although a crash is going to create a mini-Chernobyl.)

    It’s mostly a matter of Energy Density: Jet A provides about 20 MegaJoules of energy per pound. My consumer LiFePO4 battery provides 0.13 MJ/lb.

    But we can’t simply compare the Energy Density of the “fuels” We have to compare the efficiencies of conversion.

    Let’s say that a modern turbine engine is 35% efficient, and that an electric airplane is 100% efficient. (A turbine engine is horribly inefficient at idle. But an electric airplane is not 100% efficient in flight either. But to make the math easier …)

    So even if a super duper battery offered 1 MJ/lb, Jet A still gives 7x in equivalent usable energy. Which means that you would need 7x the weight in batteries compared to Jet A just to get the same long distance endurance of an Air Transport. (This ignores whether you could get the required max Take Off Power from electric motors + batteries needed for a fully loaded Air Transport. If you can’t get that, then we can’t even get this discussion off the ground.)

    And even if you had 30,000 lbs of batteries (the equivalent of a full tank of Jet A in small Boeing’s) that could deliver the Energy Density of Jet A, the advantage still goes to Jet A, because as a flight progresses, you burn off fuel, making it so that the (trans-oceanic) aircraft can fly farther – or higher – as the plane becomes lighter. Whereas when you take off with 30,000 lbs of batteries, you carry 30.000 lbs of batteries with you for an entire flight, capping both your Endurance/Range and Service Ceiling.

    (You can’t carry the Max TakeOff Weight in batteries anyway, because you have to allow for Max Landing Weight. So you can’t even carry 30,000 lbs of batteries for Take Off.)

    Not to mention that you can replace all that Energy in Jet A in about a half hour on the ground via refueling. How long does it take to charge a dinky Tesla? How long it would take to charge up a huge Electric Air Transport – if we had the Infrastructure? (Which we don’t. Which is a whole ‘nuther part of the All Electric Equation.)

    In the end, the whole idea of an All Electric Air Transport comes up short. (Pun intended.)

  7. The Soloy Pathfinder 21 is a twin engined Cessna 208 Caravan with a single propeller. This would be the most ideal way to prove electric motor technology. Artificial Intelligence (AI) could learn the best balance of electric and petroleum power. The commercial market needs to exercise these new technology and prove their efficiency and reliability.

    Micro-Turbines are available now and can generate enough electricity to charge the available battery technology. Today’s technology is not ready to jump with both feet into battery standalone power.