https://cleantechnica.com/2020/11/06/ev ... e-in-2022/

Manufacturer claims $200 an hour operation costs. If this is actually deliverable the future may be here.

Yawn. They haven't made a single flight, and didn't their prototype burn up earlier this year?

I'm as supportive as the next person when it comes to technological advancement, but the Eviation Alice still seems like so much vaporware.

AirlineBob wrote:

Yawn. They haven't made a single flight, and didn't their prototype burn up earlier this year?

I'm as supportive as the next person when it comes to technological advancement, but the Eviation Alice still seems like so much vaporware.

Fire was attributed to a ground based battery system:
https://www.ainonline.com/aviation-news ... ound-tests

That doesn't mean it is a bad concept. But it should be noted that the takeoff weight is 60% battery! that means any other weight loss is negligible. That means higher energy density batteries are required to make the technology practical and battery, we need a new battery technology.

https://www.epectec.com/images/battery- ... ensity.jpg

In my opinion, we are hitting the limits on current battery technology and that means there is little growth. Aircraft need to triple range to be effective. How is that going to happen? That is my concern. There just isn't much to do with structures, the electric motor or conversion systems (from DC to a rectified AC for the motor), aerodynamics, or the propeller. At least not anything that won't benefit a conventional aircraft even more.

There needs to be a significant battery breakthrough for even turboprop replacement.

Lightsaber

Just like electric cars, this is totally dependent on battery technology. I drove some of the first electric cars with a range of just 80 miles and they were not practical for long-distance trips. Now, most models have over 200 miles of range.

The same is true with planes but here the main factor is weight rather than cost. At first, these planes will have very limited range and can only be used for extremely local flights. But within the area that they can travel, they will change everything.

The more knowledgeable replies on the cleantechnica site are pretty critical of eviation. I do believe that carrying 9 passengers for 100-200 miles at the beginning would be a useful plane. But battery packs need to be easy and cheap to swap out as more energy dense batteries are developed. I also don't think it needs to go all that fast to be useful. Having lived much of my life in rural areas I tend to judge these things as how they could connect more isolated areas with connections to more major airports. It is amazing but most of the rural population in the US is within 200 miles of a 'major' regional airport.

Liquid hydrogen in tanks is lighter than batteries, right? So why aren't fuel cells on the horizon for aircraft?

First, while H2 has lots of energy, it is light, so you need lots of volume to go a ways—meaning large cylinders or bottles to carry under pressure. Then, it’s stored at cryogenic temperatures which is hard on materials—lots of maintenance and dangerous for passengers, so they have to be separated from the H2 storage tanks. Works good for rockets that don’t work for thousands of hours or capsules that need finite amounts of electricity from the fuel cell, not so much elsewhere.

I think current battery technology can easily provide a 500+mm aircraft. That covers more than a third of all commercial flights.

The thing is an electric aircraft will take off at a weight 2-3 times higher as a similar capacity turboprop aircraft. As landing fees are based on weight it kills the economics. Changing how these fees are calculated hopefully will be easy.

In 10 years time battery tech will turn a 500nm range electric aircraft into a 750nm range aircraft. That now covers more than half of all commercial flights.

A long range ATR sized design could fit a small generator like an existing 787 APU in the tail that gives a 50% range extension. That would now allow a design to cover more than three quarters of all commercial flights.

Liquid hydrogen in tanks is lighter than batteries, right? So why aren't fuel cells on the horizon for aircraft?

Correct, fuel cells are considered by many including Airbus and ATR as the real future of electrical propulsion.

There are a few challenges ahead of course.

Liquid hydrogen in tanks is lighter than batteries, right? So why aren't fuel cells on the horizon for aircraft?

Correct, fuel cells are considered by many including Airbus and ATR as the real future of electrical propulsion.

There are a few challenges ahead of course.

Of course the OT electrical aircraft is not available. It is proposed, as best.

The major milestone and actual prerequisite for market access will be type certification, and before that application for certification to reputed regulator such as EASA, Transport Canada or FAA.

RJMAZ wrote:

I think current battery technology can easily provide a 500+mm aircraft. That covers more than a third of all commercial flights.

The thing is an electric aircraft will take off at a weight 2-3 times higher as a similar capacity turboprop aircraft. As landing fees are based on weight it kills the economics. Changing how these fees are calculated hopefully will be easy.

In 10 years time battery tech will turn a 500nm range electric aircraft into a 750nm range aircraft. That now covers more than half of all commercial flights.

A long range ATR sized design could fit a small generator like an existing 787 APU in the tail that gives a 50% range extension. That would now allow a design to cover more than three quarters of all commercial flights.

Those weight based fees go to pilot pay and airport certification. I agree a hybrid could extend range, but there is a point where the twin turboprop is more efficient due to the weight.

Recall, a hybrid is hauling not only the fuel cell, but that extra engine and fuel system. The only advantage of a single engine hybrid is in an engine out, the diversion is on battery and the engine could be sized just for cruise (takeoff and climb either both or off battery to minimize urban emissions). We have another thread on a PC-12 ditching despite an incredibly reliable engine.

I believe you are optimistic on real world range with reserves off batteries. As someone who lives in the western USA, there isn't yet enough range to be interesting.

For Florida flight schools? Sure!

Lightsaber

Until there is a significant weight saving on battery tech most of these proposed aircraft won't be a commercial success. How many airshows do you go to where there is a trade display stating that the "latest and greatest" next gen aircraft is about to become a reality..... They are often rebadged under a different name and show up at each show promising the same great result year after year while they hunt for investors. Alternative tech / fuel is going to come for sure but not in the timeframe that a lot of these companies are promising particularly when the rest of the industry are not geared up to support them.

Bjorn Fehrm over at Leeham News has two very interesting series covering the electric and h2 aircraft

Just search for "The challenges of Hydrogen" and "ePlane"
Very interesting read!!!

Cheers
JD Evora

vhtje wrote:

Liquid hydrogen in tanks is lighter than batteries, right? So why aren't fuel cells on the horizon for aircraft?

Hydrogen is very expensive. 4 times as much as gasoline (for toyota hydrogen based cars at least)

https://cleantechnica.com/2019/04/26/hy ... 0car%20too.

I guess it can work for 1 hour flights.

AirlineBob wrote:

Yawn. They haven't made a single flight, and didn't their prototype burn up earlier this year?

Detail from fire incident report points to the prototype's lithium-ion batteries as the culprit.....

https://www.flightglobal.com/airframers ... 28.article

vhtje wrote:

Liquid hydrogen in tanks is lighter than batteries, right? So why aren't fuel cells on the horizon for aircraft?

I think they both are, including retrofits like Harbour Air are aiming for. Electric will also be very useful and lower costs for flight training. Once solar power can be built into a fuselage, range should improve 10-20%.

I read last week how University of York researchers think they’ve found a way to improve battery density by 25%.
In the same way 100 km range driving was advanced 10 years ago, 10 years from now, 400 km range driving will seem underwhelming. Translate that to aviation and suddenly 300 km trips on a 50 seater become viable with 1 hour or less turnaround times thanks to superchargers.

Hydrogen then takes over for longer trips and larger aircraft types.

D301 - There is not enough surface on a plane to produce useful amounts of electricity, I suspect it would take upwards of a few Hectares.

frmrCapCadet wrote:

D301 - There is not enough surface on a plane to produce useful amounts of electricity, I suspect it would take upwards of a few Hectares.

Solar Panels on the frame would not provide primary source of electricity, but would add onto the on-board energy; if you can add even 5-10% of range just with that feature, why not do it? Bonus: it would most likely reduce cabin temperature by shielding it from UV Rays.

https://www.flightglobal.com/airframers ... 88.article





It looks like this might be the redesigned version that could end up entering service. I like it. Looks to be a traditional low risk design that could be much easier to certify. They would have saved a lot of time and money by picking a conservative aircraft layout to begin with instead of going with something so exotic that it never had a chance in hell of being certified by the FAA.

that's a major redesign... a program reboot

alberchico wrote:

https://www.flightglobal.com/airframers/is-this-the-new-look-for-eviations-alice/141988.article





It looks like this might be the redesigned version that could end up entering service. I like it. Looks to be a traditional low risk design that could be much easier to certify. They would have saved a lot of time and money by picking a conservative aircraft layout to begin with instead of going with something so exotic that it never had a chance in hell of being certified by the FAA.

Electrifying design! Hope it moves ahead.

I also heard Harbour Air plan on resuming EV flight testing shortly after Covid suspended the project for a few months.

Claimed performance is/was : With 260 Wh/kg cells, the 900 kWh battery capacity (3,460 kg, 7,630 lb) is initially estimated to give the design a range of 540–650 nmi (1,000–1,200 km) at 240 knots and 10,000 ft (3,048 m).

That's plenty useful in Europe at least, for routes where there aren't good alternatives to flying. In countries where "flight shaming" is becoming a thing, that might help, too.

Electric GA aircraft are slow coming but really exciting, for example this one : https://en.wikipedia.org/wiki/Bye_Aerospace_eFlyer_2

I expect the operating costs of piston engines will soon be difficult to justify.

One area of risk is that the FAA might require design changes to improve safety that might add weight and eat into the range and payload. This article explains the problems that another futuristic aircraft design had in trying to get certified.

https://airfactsjournal.com/2018/01/why ... -disaster/

9 passengers and a pilot and co-pilot, the chances of making a profit are nil. Smaller mainline and regional planes are falling out of favor with airlines. The trend is larger planes. A 9 seat airliner is just a toy and not practical for commercial travel.

Thanks for the update. Eviation's redesign appears to have met the objections posted on this site. I still think an initial range of 300-500 nm is more than adequate, and could reestablish regional flying throughout much of the world. Single pilot operations for up to 20 passengers can come later. Perhaps I should start a thread in 'technical', no expertise, but I have a lot of questions.

airlineworker wrote:

9 passengers and a pilot and co-pilot, the chances of making a profit are nil. Smaller mainline and regional planes are falling out of favor with airlines. The trend is larger planes. A 9 seat airliner is just a toy and not practical for commercial travel.

Cape Air and a few others might disagree.

LightChop2Chop wrote:

airlineworker wrote:

9 passengers and a pilot and co-pilot, the chances of making a profit are nil. Smaller mainline and regional planes are falling out of favor with airlines. The trend is larger planes. A 9 seat airliner is just a toy and not practical for commercial travel.

Cape Air and a few others might disagree.

True, but Cape Air has pretty limited capital investment and a wealthy primary clientele.

300-500 nm range works fine until KACK fogs in and the nearest legal alternate is KBGR.

GalaxyFlyer wrote:

LightChop2Chop wrote:

airlineworker wrote:

9 passengers and a pilot and co-pilot, the chances of making a profit are nil. Smaller mainline and regional planes are falling out of favor with airlines. The trend is larger planes. A 9 seat airliner is just a toy and not practical for commercial travel.

Cape Air and a few others might disagree.

True, but Cape Air has pretty limited capital investment and a wealthy primary clientele.

300-500 nm range works fine until KACK fogs in and the nearest legal alternate is KBGR.

I can think of quite a few Cessna 208 operators around the world that pre pandemic were profitable and doing quite fine.

A single-pilot 208 in a short range VFR operation is a different kettle of fish than an airline buying new, unproven technology.

LightChop2Chop wrote:

airlineworker wrote:

9 passengers and a pilot and co-pilot, the chances of making a profit are nil. Smaller mainline and regional planes are falling out of favor with airlines. The trend is larger planes. A 9 seat airliner is just a toy and not practical for commercial travel.

Cape Air and a few others might disagree.

I liked Cape Air for the great views from those 402s. And snagging the copilot seat was always good, although the pilot usually wanted the cutest girl on the plane there for weight distribution reasons.

It's hard to separate facts from wishes, but you can probably count on 350wh/kg cells in a few years. They don't seem to want to disclose weight for some reason, but the new 4680 cells look about there.
If these guys published real specs, I bet you'd find them assuming things like the plane somehow magically using 1/3 the horsepower of a lighter conventional aircraft the same payload. They always seem to count on future improvements that could as easily be rolled into fossil fuel eaters.
And until all electricity is non carbon making, hydrogen won't make much sense. As far as electricity into the H2 maker/battery cell to electricity out of the battery/fuel cell ratio, hydrogen if less than half as efficient as batteries.
As already said, batteries are the key. Both inverters and motors are already so close to maximum theoretical efficiency, there's not much left there. Telsa gets 500hp at something like 94% efficiency out of an amazingly small motor.

alberchico wrote:

They would have saved a lot of time and money by picking a conservative aircraft layout to begin with instead of going with something so exotic that it never had a chance in hell of being certified by the FAA.

It sounds to me like the typical tech startup arrogance of stepping into a new field and feeling the need to reinvent everything to shakeup the established arthritic players...
Except this time, they stumbled into a highly technical, highly regulated market with enormous capital investment needs and razor thin margins which has left countless enthusiastic entrepreneurs biting the dirt before them...

Aviation is not an industry in which the Silicon Valley attitude works very well.

That being said, now that they got their dose of realism, I wish them the best.

Nomadd wrote:

LightChop2Chop wrote:

airlineworker wrote:

9 passengers and a pilot and co-pilot, the chances of making a profit are nil. Smaller mainline and regional planes are falling out of favor with airlines. The trend is larger planes. A 9 seat airliner is just a toy and not practical for commercial travel.

Cape Air and a few others might disagree.

I liked Cape Air for the great views from those 402s. And snagging the copilot seat was always good, although the pilot usually wanted the cutest girl on the plane there for weight distribution reasons.

It's hard to separate facts from wishes, but you can probably count on 350wh/kg cells in a few years. They don't seem to want to disclose weight for some reason, but the new 4680 cells look about there.
If these guys published real specs, I bet you'd find them assuming things like the plane somehow magically using 1/3 the horsepower of a lighter conventional aircraft the same payload. They always seem to count on future improvements that could as easily be rolled into fossil fuel eaters.
And until all electricity is non carbon making, hydrogen won't make much sense. As far as electricity into the H2 maker/battery cell to electricity out of the battery/fuel cell ratio, hydrogen if less than half as efficient as batteries.
As already said, batteries are the key. Both inverters and motors are already so close to maximum theoretical efficiency, there's not much left there. Telsa gets 500hp at something like 94% efficiency out of an amazingly small motor.

4680 actually has a lower volumetric density. It's 5,5 bigger in volume and only provides 5 times more energy. The 4680 has been only about production cost not about density. The total package would increase in density by making batteries the integral part of the structure, but in aerospace this has been quite common to use energy storage as an integral part of the structure. So, the 4680 brings nothing interesting to the table for aerospace...

GalaxyFlyer wrote:

A single-pilot 208 in a short range VFR operation is a different kettle of fish than an airline buying new, unproven technology.

I imagine quite a few wealthy people would be ready to help prove the technology, I wonder why they're not marketing it also as a private aircraft.

Range vs weight is one major issue, another is the recharge rate.

The "superchargering" stations around on the roads help cars need less time to wait around and they are getting faster DC chargers, but I imagine that with an aircraft, the amount of batteries will be at least 3x as many. Batteries also get best charge in their "peak" range, which is normally up to 60% charge, and then slow down to help keep battery life up.

These battery banks will have to be easily removable then for quick turnarounds (unless the flights are very short range) which will then mean that every out station will need some serious power chargers, which may not be easy to be placed on airports either (due to regulations that will probably not want a massive battery fire around fuel and pax buildings). If they are not removable, then if you get this 300nm flight in, it will take probably 4+ hours to recharge to full again and that's not very profitable for airlines!

Aesma wrote:

GalaxyFlyer wrote:

A single-pilot 208 in a short range VFR operation is a different kettle of fish than an airline buying new, unproven technology.

I imagine quite a few wealthy people would be ready to help prove the technology, I wonder why they're not marketing it also as a private aircraft.

Not a chance! I’ve been involved in high end business jets for 16 years—they don’t care a jot for proving technology. How ‘bout, “it’s a six hour flight from NYC to London tonight, sir”. “I want a solid eight hours sleep, delay the arrival, please, Captain”. So, we circle around Labrador for 2 hours, get our oceanic clearance to London and proceed to the amusement of Moncton and Gander Control. John Kerry, owner of several yachts, houses and private planes is our climate czar. GMAB.

airlineworker wrote:

9 passengers and a pilot and co-pilot, the chances of making a profit are nil. Smaller mainline and regional planes are falling out of favor with airlines. The trend is larger planes. A 9 seat airliner is just a toy and not practical for commercial travel.

9 pax don't need a co-pilot, and EASA seems to show interest in relaxing single pilot rules. I would say single pilot 19 pax is a safe bet in the near future.

https://www.flightglobal.com/safety/eas ... 31.article

Ziyulu wrote:

I guess it can work for 1 hour flights.

There's at least a dozen commercial air service airports within an hour's flight of ATL. Just one example, but the "last mile" problem in passenger air service doesn't need a CRJ solution.