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ZeroAvia & Otto Aviation partner to deliver first new airframe design with hydrogen-electric engine option

Hydrogen-electric aviation company ZeroAvia will collaborate with Otto Aviation, LLC, to develop a hydrogen-electric powertrain to power Otto’s Celera aircraft.



Under the agreement, Otto and ZeroAvia will work to integrate ZeroAvia’s ZA600 zero-emission engines to Otto’s Celera aircraft. The collaboration has the potential to make the Celera the first new airframe design to leverage zero-emission propulsion in its launch models.

The Celera is an innovative new model of transcontinental aircraft, scalable to 19 passengers, that significantly improves the efficiency of flight and reduces the operational costs of flying as a result. This combination significantly expands the opportunities for private air transportation.

Otto’s advanced aircraft design offers exceptionally low drag across the entire aircraft. The design of the Celera fuselage, empennage and wings take advantage of laminar flow. Laminar flow is the minimum drag solution for aircraft surfaces and features smooth layers of airflow with little to no mixing of adjacent layers. When coupled with highly fuel-efficient propulsion systems, the Celera will significantly reduce operating costs and increase range relative to comparable aircraft, while creating optimal passenger comfort and cargo capacity.


When powered by ZeroAvia’s powertrain, the Celera will offer long range zero-emission flights, while further reducing operating costs, thanks to reduced maintenance costs and falling hydrogen-fuel prices. The Celera design is highly conducive to accommodate large volumes of hydrogen within the fuselage that will enable 1,000 nautical miles of range—all with zero climate impact from carbon and non-carbon emissions (like NOx, SOx and particulates).

With non-carbon emissions from relatively inefficient, high temperature combustion contributing over half of the total climate impact of aviation, long range hydrogen-electric aircraft such as Celera will play an important role in eliminating all climate impacts of aviation.

The majority of our commercial deals to date have focused on retrofit and line-fit for existing airframes, which is essential to deliver zero-emission flight to market as quickly as possible. However, efficiency gains from new airframe design can expand the impact of zero-emission aviation. We are pleased to collaborate with innovators, like Otto Aviation, bringing cutting-edge clean sheet designs to market as we can optimize the hydrogen-electric propulsion system for those designs.

—Val Miftakhov, Founder & CEO ZeroAvia

Announcing the partnership today, William Otto, CEO of Otto Aviation, said: ​

ZeroAvia’s mission is to deliver hydrogen-electric engines into every aircraft, having identified the technology as the most practical, economical, and furthest reaching solution for reducing aviation’s climate change and clean air impacts. Hydrogen-electric engines use hydrogen in fuel cells to generate electricity, which is then used to power electric motors to turn the aircraft’s propellers, with the only byproduct being water.

The development of this 600kW powertrain is part of Project HyFlyer II and will deliver a fully certified powertrain for aircraft of up to 19-seats by 2024. HyFlyer II is supported by the UK Government’s Department for Business, Energy and Industry Strategy (BEIS), Aerospace Technology Institute (ATI), and Innovate UK through the ATI Programme.

After having flown multiple 6-seat R&D prototypes, ZeroAvia is preparing its first 19-seat prototype for its inaugural flight in the coming weeks. The company is also retrofitting a second Dornier-228 testbed in Hollister, California, to conduct further flight testing.



Great news


I wish them success! As an aeronautical engineer, I recognized the Otto design perfection. Better performance in it's class is probably not achievable. Combining it with best in class zero emissions power is a match made in heaven. My only issue is perhaps NH3 would be a better fuel choice, as others have concluded.


LH2 would give them range, it can be made from RNG.


They seem to have settled on hydrogen for aircraft, at Airbus and others as well as these guys.

What I would like to see though is retrofitting of conventional aircraft using ammonia, as the brilliant folk at Reaction Engines have suggested:


I wish the well, but I wouldn't put my life savings into the company.
It is mainly about laminar flow, and as the wiki article says, "laminar flow tends to be unreliable in service, as it is highly susceptible to degradation from surface irregularities."
Hence no passenger windows in the prototype.
If it is as efficient as they suggest, they could just run it on diesel as originally planned. They should get it running reliably (and in service with customers) with a conventional engine, and then go for H2 or NH3 or whatever.
Maybe they are just doing this to raise more money.
Anyway, I wish them well and every success.


Looks a bit like a whale but maybe that is a good thing for efficiency as are the long thin wings. It is just a concept but I would like to see more of the proposed specs including cruise speed, stall or landing speed, range, payload, etc.

As mahonj said, I would not recommend investing in this venture. Also, I really doubt that hydrogen will be used for commercial aircraft as the costs are too high and the volumetric energy density is too low. I am planning on going to the Experimental Aircraft Association's Airventure show in Oshkosh next month so I will see what Boeing, Airbus, along with Pipestrel, Bye Aerospace, maybe Eviation and other have on display for electric aircraft but I really do not expect to see much on hydrogen.


liquid hydrogen has a density of close to 71 kg/m3
Same space as 200 gallons of jet fuel


@ SJC:
So what?! You're ignoring all the measures and subsequent financial impacts necessary to produce H2 and keeping it liquid at a steadily increasing environmental temperature rise. Completely absurd!


@ SJC:
Liquid hydrogen has about 10 GJ/m**3 while Jet A has about 35 GJ/m**3 but the real problems are the energy and monetary costs of making liquid hydrogen and the problems of transporting and dispensing a fluid that is 20 deg C above absolute zero (−423.182 °F). I sincerely doubt that this will happen anytime soon for private or commercial aircraft.


Fuel cells are more efficient than jet engines


Plus you save over 1000 pounds of weight on a 600 mile trip


1. The latest cryogenic tank design is very lightweight and will allow LH2 to be stored on board an airplane for an extended period of time. The boiloff will help to maintain the LH2 temperature, and run through the fuel cell to keep all the electronics on board operating and the passenger compartment comfortable and pressurized.

2. LH2 needs to be produced at a commercial airport to reduce cost and headaches in trucking it in. Renewables and grid power will be sufficient for GA airports. For the 350 major commercial airports in the U.S., a small nuclear plant will work fine. The newer safer designs are compact and can supply all the power a major airport will need in addition to producing LH2. This will reduce the stress for the grid, as well.

3. Burning NH3 in a diesel engine would work well with a small quantity of NOx in the emission. Producing NH3 from coal would be good for more jobs and using up our coal resources, but CO2 is produced in the process as it is in using natural gas. If capturing CO2 at an affordable cost during the coal conversion process, then that would be good.


Those who seek to dismiss whole vast areas of technology, and those working in it, with sweeping assertions have an absurdly high opinion of themselves, often wholly without knowledge or expertise.

Airbus, for instance, to name just one. are working right now on hydrogen for aircraft, including the cyrogenic tanks needed.

Maybe it will work, maybe it won't, and there are no guarantees, but they are certainly not just innumerate morons, nor are their financiers.

Scepticism is fine. Blanket dismissals are folly.


Hi sd.

Using liquid hydrogen in aircraft is certainly challenging.
You are probably well aware of Airbus's approach, but anyway here are a couple of links to their development of storage technology:

Of course there are multiple other issues as well as on board storage of hydrogen, but my view would be that it is preferable to look at them separately instead of bundling the lot and getting buried, as we are actually very good at actioning very complex technological integration.

So for instance it now appears that renewables to ammonia and then to hydrogen can be done with excellent efficiency, and ammonia could certainly be provided at airports to be chilled and liquified.

But there are numerous other possible approaches which can't be ruled out.


Here is an analysis of theoretical and actual energy losses in liquifying hydrogen:

As can be seen, worse case is something like a third of the energy embodied in the hydrogen, using off the shelf current technology.

That is certainly not high enough to rule it out, in my view, and multiple strategies are possible to reduce it.

Fortunately both liquid hydrogen tanks and liquification technologies are currently being developed for use in heavy long distance transport by the likes of Daimler, so the aircraft industry does not have to do it all itself.


Liquid hydrogen is -200f at 1000 PSI

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