Claiming 300 to 500 mile range. Could do that with batteries a lot cheaper and simpler. Boris might have been sold a pup here.

Davemart
I agree the engineers are not morons.
They are doing what they are being paid to do.

I am sure they can probably build a hydrogen fueled plane. The question is why.
To provide 700bar hydrogen at the small airports this plane is aimed for is problematic.
Hydrogen will always be expensive(unless made from fossil fuels).
With the incremental increase in energy density and the drop in price of batteries hydrogen may have a niche position but cannot compete in the market place without financial help or the use of fossil fuels.
As sd relates in a lower comment there is a 9 seater with a range of 420 miles running on batteries and they planning to fly the hydrogen Malibu 300 miles.

@yoatmon,
Aircraft can use Liquid H2 (LH2) as fuel, which weighs 1/3 that of petroleum fuel for a given amount of BTU. Then, for 19-seat passenger aircraft, the FC is 3 x more efficient than an equivalent 400-600-kW gas turbine. So, already, we may end up with fuel weight about 1/9 that of the jetfuel weight just on the basis of 3x gains in thermal efficiency and 3x gain in gravimetric energy density.

Ah, but there's more: Fuel weight is generally 1/2-2/3 of useful load of the aircraft, with the remaining for payload, and fuel weight can be as much as 1/3 to 1/2 of the gross takeoff weight.. Thus, the entire aircraft can be downsized to have smaller wings, smaller tails, smaller propulsion system, smaller landing gears which will save even more weight and would end up consuming 75% of the energy per mile per kg of payload. So, multiplying 3 folds thermal efficiency gain of the FC with 1.33 folds gain in energy efficiency per unit of payload due to weight and drag reduction = 4 folds gain in fuel efficiency when converted to LH2-FC propulsion system. So, the LH2 fuel weighs practically nothing when so little of it is being used, AND with 3 folds higher in energy content per unit of mass: 4 x 3 = 12 folds lower fuel mass per kg of payload. Let's say that the Cessna Caravan carries 2,200 lbs of jetfuel, then an equivalent-payload LH2-FC plane would carry only 183 lbs of fuel, or just the weight of ONE passenger.

This extremely low fuel mass has major implication in the crash safety of the aircraft, with high percentages of deaths of current small plane crashes from post-crash fire from otherwise survivable crash. Jetfuel is placed in the wings, which is very likely to break up after even a low-impact crash, causing fuel rupture which will cause lethal fires. The LH2 fuel tank could be placed in well-protected insulation structures (thick polyurethane foam) in the rear of the fuselage whereupon the fuel tank holding very light fuel will very likely stay intact after a survivable crash. Rear section of aircraft always stay intact after impact-survivable crashes.

So, LH2 is very advantageous for aviation, and we are bound to achieve as much as 12 folds gain in fuel efficiency in comparison to petroleum fuel in small aircraft, and much gain in safety at the same time from post-crash fires and from increase reliability of the propulsion system, with dual e-motors and dual FC system powering a single propeller.

Another way to look at LH2 fuel consumption per lb of payload is to realize that for the Cessna Caravan with 8,000 lbs gross weight, 4,700 lbs empty weight, and 3,300 lbs usefull load, with maximum fuel weight of 2,200 lbs, it has only 1,100 lbs of payload.
Even if the aircraft is not downsized, then when subtracting the 244-lb of LH2 (2,200 lbs divided by 9 folds less fuel mass) from the 3,300 lbs of useful load, we would have 3,056 lbs of PAYLOAD available for the full range as with 2,200 lbs of jetfuel earlier, but now, with the huge PAYLOAD of 3,056 lbs, we almost TRIPLE the payload capacity for the LH2 in the non-downsized version of the Cessna Caravan as the result of using LH2-FC propulsion system.

So, we have almost tripled the payload capacity, while using only 1/3 of the fuel caloric value due to 3 folds gain in thermal efficiency of the FC would means 9 folds gain in fuel efficiency of LH2 per lb of payload.

Roger Pharm
First luv your work Roger.
But this time youve strayed into fanciful territory.
Claiming that FCs are 3X as efficient as turboprops is a bit of a stretch. We know that PEMs are ~50% efficient at best and that energy must then be translated to motive power via an emotor , a loss of another 10% so 45%.
The present F1 engines are claiming >50%. Toyotas 4 cylinder engine claims to have efficiency >40%. Big diesels are also getting ~45%.
But I do agree that PEMFCs would be more efficient than turboprops.
The real problem is liquid hydrogen. I get flashbacks of the Challenger disaster.
Handling the stuff at -250 to-260 degrees C, in a commercial setting, nup.
If you really must have FCs ,then go for SOFCs with a liquid fuel.
Not really green but you could call it biofuel.

@bman,
Thanks for your comment and feedback.
1.. Regarding the efficiency of FC, new generation of higher-temp FC is now able to reach 70% efficiency with temperature of 150 dgr C, thus allowing significant reduction in the size of the radiator and making higher power possible in aviation. Also, power density of as much as 6 kW per liter and 4 kW per kg is now possible, while motors having 5-6 kW per kg is now available, making the weight of the entire propulsion competitive with turboprop. Of course, peak power is only needed for a few minutes during takeoff at full gross weight, and can be throttled back to 75% during climb, and way back during cruise at altitude.

2.. Regarding the Challenger disaster, from Wikipedia: "The disintegration of the vehicle began after a joint in its right solid rocket booster (SRB) failed at liftoff. The failure was caused by the failure of O-ring seals used in the joint that were not designed to handle the unusually cold conditions that existed at this launch. The seals' failure caused a breach in the SRB joint, allowing pressurized burning gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB aft field joint attachment hardware and external fuel tank. This led to the separation of the right-hand SRB's aft field joint attachment and the structural failure of the external tank. Aerodynamic forces broke up the orbiter." There is no mention of LH2 at all as having anything to do with this disaster. Just the solid boosters and aerodynamic forces the broke up the vehicle.

3.. With LH2, the very light nature of it and the thick polyurethane foam insulation required means that the fuel tank is very strong and big for the inertial force of the fuel and should hold up very well, far better than heavy petroleum fuel in flimsy aluminum skin fuel tanks inside the wings. Would a fuel tank leak cause fire? Since the fuel is so cold, no fire can happen adjacent to the aircraft, but much further behind and above the aircraft, as the LH2 has the chance to vaporize and gain heat and floats upward and mixed with air. A lot of steps must happen before the cryogenic LH2 can catch fire, well above and behind the aircraft.

Roger Pharm
Thank you for your well crafted comment.
The 70% efficiency for 150degreeC FC is stated as a target.
Ive seen cell startups "targeting " 400wh/kg for years now.
I truly hope both come true but I reckon the batteries might get there first.