ZeroAvia has been granted a permit by the U.K.’s Civil Aviation Authority (CAA) to fly a modified Dornier 228 outfitted with the company’s prototype hydrogen-electric powertrain. ZeroAvia noted that the permit was granted after an “extensive ground testing campaign and a rigorous review of the full development program.” Scheduled to fly for the first time in January 2023, the 19-seat twin-engine aircraft will be operating with the 600-kW hydrogen-electric powertrain on its left wing and the stock Honeywell TPE-331 engine on its right wing.
“Earning our full Part 21 permit to fly with the CAA is a critical milestone as we develop a zero-emission aviation propulsion system that will be the most environmental and economical solution to the industry’s climate impact,” said ZeroAvia founder and CEO Val Miftakhov. “We’re going to be starting 2023 in the best way possible, by demonstrating through flight that true zero-emission commercial flight is much closer than many think.”
The modified Dornier 228 is part of ZeroAvia’s HyFlyer II project, a U.K.-government-backed program working to develop a hydrogen-electric powertrain for 9- to 19-seat aircraft. The company stated that it worked with the CAA to meet “a far more stringent set of requirements when compared to the E-Conditions framework ZeroAvia had used for its 6-seat prototype in 2020.” ZeroAvia’s HyFlyer I program began flight testing a 250-kW hydrogen fuel cell powertrain using a modified Piper PA-46-350P Malibu Mirage in September 2020. Although the aircraft experienced an inverter lockout that resulted in an off-airport landing last year, the company reported that it was able to continue testing and that HyFlyer I accomplished all of its technical goals.
It is great to see testing of new technology that has the potential to be practical. Hydrogen has much better energy density than Li-Ion batteries. It remains effective in temp extremes and we know how clean it is. Although on earth it has to be cracked from water, it is the most abundant substance in the universe. Then again, it seems no source of power comes free of charge. Mining for Lithium and Cobalt as well as building batteries and generating electricity comes at a cost.
Thus far, batteries don’t seem to cut it. I know our Arrow can range about 500 miles with reserves on about 500 lbs of fuel. Batteries that permit the same performance would weight far more than the airplane itself. I think H2 has possibilities.
Hydrogen doesn’t need to be cracked from oxygen in water molecules, and in fact that’s not where most of our commercial hydrogen comes from. It’s much easier to break the hydrogen atoms away from the carbon atoms in a hydrocarbon molecule. (That molecular bond takes much less energy to break.) Guess where we get our hydrocarbons from?
Would you say a Hydrogen electric system is more or less complex than a conventional piston engine?
A big selling point of electric planes is the reduced complexity and maintenance. This thing sounds like the maintenance is going to require more expensive mechanics and require a lot of time learning dangerous lessons. Is it really worth it? Converting ground vehicles would seem to be the more important priority for reducing carbon anyways.
Ignoring the issue of how to produce the hydrogen, the bigger issue is how to store it on an aircraft. The only “practical” method is to store it as a liquid – a high pressure gas tank of that volume would be way too heavy. And, hydrogen is a liquid at around -423 degrees F (-253 C). Just ask Boeing about the challenges of handling liquid hydrogen on their Artemis rocket. Production, storage and handling of cryogenic liquids requires extensive training for employees, far above the level of the typical aircraft line crew. Electric fuel cells sound great until you start figuring out how to feed them in the air.