EVTOL news and progress - do we need a new dedicated section?

[ETOPS]

Dear all (and esteemed mods)

I've been following developments in the future EVTOL industry with such companies as Beta Technolgies, Joby, Wisk and Archer Aviation.
I think now is the time to declare this industry a "thing" and accept that they are moving rapidly to the start of revenue flights. My guess is late 2024 or into 2025 for Joby for instance.

My thought is for a seperate section to avoid this new technology getting jumbled up with the conventional Rotorcraft forum.

As evidence take a look at this latest Joby news from New York........

https://www.youtube.com/watch?v=0VoKNTAAvmA

I don't think we will be able to ignore these operations and should really be able to track and discuss how this unfolds.

[procede]

The vehicles are quite impressive from an engineering perspective, but they are basically reinventions of the helicopter but then with much lower range.
And just like helicopters the costs are high and there are so many operational limits due to safety and noise that there is no sustainable business model.

Also: Just because it is electric does not mean it is sustainable.

[Lonewolf_50]

It's a luxury item for wealthy people, at present. (Like car phones were in the 80's and 70's).
When that changes the industry will (I suspect) have a niche that it fills.

[ETOPS]

and noise

I think the whole point of the Manhattan demo was to showcase the low noise signature. The clever graphics towards the end were very interesting.
Hearing in person will be proof, or otherwise.

[procede]

The issue is that, as with supersonic aircraft, the niche is too small to be economically sustained. The higher the cost per aircraft, the fewer aircraft, which leads to an even higher cost per aircraft, etc.

Also, an empty aircraft with near to no range is always going to be very quiet, but it is not representative for a commercially viable one.

[EDLB]

Wake me up if they manage 100nm range + legal IFR reserve. Don't think that will happen within 20 years from now.
Operational I see no difference to Jet A1 burning helicopters. And the Jet A1 fuel ist not the mayor cost driver. So what is new beside much less range and performance?

[Andrewgr2]

Wake me up if they manage 100nm range + legal IFR reserve. Don't think that will happen within 20 years from now.
Operational I see no difference to Jet A1 burning helicopters. And the Jet A1 fuel ist not the mayor cost driver. So what is new beside much less range and performance?
Most of the reports I’ve read seem to suggest that their promotors think they will operate as autonomous air taxis in urban environments That would be new!

[ETOPS]

Congratulations procede

Your post qualifies as the first EVTOL "fear, uncertainty & doubt" with shades of the early EV car doubters. The machine featured on the video is a production standard example and is the first to be flown manually. All previous examples were "experimental" and also flown remotely. FAA certification is proceeding (see what I did there) and all we need to do is have a little patience to see this come to fruition over the next year or so.

an empty aircraft with near to no range
It has the range it was designed for.....100 miles. Given that the LA basin initial operations have already been given Part 135 certification with planned networks of less than 100 miles I reckon 2025 will their Tesla moment...

[wrench1]

Most of the reports I’ve read seem to suggest that their promotors think they will operate as autonomous air taxis in urban environments That would be new!
Its not new per se. Just a progression of the UAM concept which started decades ago and has since been included under the newer concept of AAM and RAM. Plenty of references out there on this if one were interested to check out.

Another reference to read on UAM is on Heli-STAR performed in the 90s which used helicopters to test parts of UAM. It was also the 1st real world test of ADSB technology. But it showed convential helicopters created to much noise and other issues to be used at street level. Regardless the UAM concept was proven which eventually led to a number of large cities developing official UAM plans that some are putting into place right now.

As to range of these eVTOLs, it was never the intent to replace existing aircraft only provide a new mode in areas where conventional aircraft cannot operate. While theres been a generation of nay sayers on this concept for decades it continues to grow and is projected to be a multi-billion doller industry within the next 10 years or so. And with the FAA, EASA, and other CAAs writing new regulations for these ops, its only a matter of time before it literally takes off. China supposedly already certified the 1st eVTOL for commercial flights and it is flying for revenue.

From my view, interesting times ahead, provided they dont start dropping out the sky and making headlines. But I doubt not even that will stop the UAM concept from moving forward.

[bafanguy]

Having no business acumen, my opinion of the concept as a business model is of no value.

But I am curious to know what the target demographic is for the pilots who'll be crewing the manned versions of the VTOL devices. And what will the training involve...rotor wing, fixed wing, vectored thrust ratings ?

Or will there be so few required that crew requirements aren't a factor ? And will the position appeal to prospective pilots aspiring to something bigger down the road ?

Eviation's Alice looks pretty much like a conventional airplane so that appears self-explanatory re to pilot ratings.

UAL's EVTOL plans will require a bunch of pilots if it goes as planned:

"Archer's initial aircraft will require a pilot."

https://arstechnica.com/cars/2023/03/united-airlines-reveals-first-evtol-passenger-route-starting-in-2025/

[Lonewolf_50]

In LA, the weather is usually pretty good, though vis can get hazy. A better market than NYC, where crap weather is quite common.
Nice post ETOPS, thanks, and I think that introduction in the LA area will allow them to gloss over the bad weather risks of dense urban environments like Manhattan ...

[ETOPS]

Agreed - not sure about icing and all those rotors :eek:

[Winemaker]

In LA, the weather is usually pretty good, though vis can get hazy. A better market than NYC, where crap weather is quite common.
Nice post ETOPS, thanks, and I think that introduction in the LA area will allow them to gloss over the bad weather risks of dense urban environments like Manhattan ...
I recently rented a Tesla after a flight so I could test drive it. I was in a hot environment, 100°F, and found that a major power suck was air conditioning. The car exhausted 75% of it's just fully charged battery in a 125 mile trip; in SoCal this might be a real issue for electric aircraft endurance. This trip convinced me there is still a ways to go before I'll consider and EV, as I do quite a bit of fairly long distance drives and weather here does stay hot in the summer.

[S.o.S.]

At first look, the noise (real levels) will be the selling point, along with the speed. However, I agree that this could remain niche with the overall cost of travel remaining high into the foreseeable future, notwithstanding that some will always pay for this.

The two front motors look as if the rotors can be moved in an arc from vertical? They appear to be on a 90 degree angle fixture and the motors are horizontal, with all the others being vertical. On distance that would give them more speed?

[ETOPS]

However, I agree that this could remain niche with the overall cost of travel remaining high

Remind me - how many niche Gulfstrean G6 series jets are in service?

[MechEngr]

At first look, the noise (real levels) will be the selling point, along with the speed. However, I agree that this could remain niche with the overall cost of travel remaining high into the foreseeable future, notwithstanding that some will always pay for this.

The two front motors look as if the rotors can be moved in an arc from vertical? They appear to be on a 90 degree angle fixture and the motors are horizontal, with all the others being vertical. On distance that would give them more speed?

The aircraft has wings and horizontal stab so doesn't depend on the rotors for lift during high speed forward flight when the two pods tilt forward. Sort of a hybrid. The design likely keeps the fixed vertical rotors to use for pitch and roll control in forward flight, yaw can be done by differential thrust of the two forward pods..

[bnt]

The Lilium prototype is looking interesting, an electric variation on a “blown wing” design. (“Sucked wing”, since air is pulled over the wing by fans.)

ywJWka1evH8

[ETOPS]

All the rotors swivel equally for forward flight hence the 200mph cruise speed.

https://media.npr.org/assets/img/2023/06/29/32_joby_aviation_aircraft-4d4efc7aa243cbce5adbac17d385e99f6bca2be5-s800-c85.webp

[EDLB]

With ducted fans the Lilium design needs 2x the power compared to an Helikopter to hover.
https://lilium.com/newsroom-detail/technology-behind-the-lilium-jet?_gl=1*12bbm1b*_up*MQ..*_ga*MTcxMTQ1NDc1NS4xNzAwMTI2NzQ0* _ga_9YC7ETNZ98*MTcwMDEyNjc0My4xLjAuMTcwMDEyNjc0My4wLjAuMA..
Even so they claim that this stage is short (<60 seconds) certification requirement will be, that under single fault condition the craft still can hover. So the enormous power for hover need to be supplied by an almost empty partial (divided into redundant sections) battery.
To my knowledge all electric aircrafts wait for the wonder battery with several multiples of the current cell capabilities.
From all battery electrification projects flight is the hardest. If you add safety concerns for passenger transport only very narrow use cases are currently left.

[Capt Scribble]

The Lilium jet design is just too 'busy' for its own good. KISS was always a good principle in aviation, that vehicle has too many moving parts!

[wrench1]

The design likely keeps the fixed vertical rotors to use for pitch and roll control in forward flight,
It depends on the design as there are a number of variations. With the Joby all props transition forward in horizontal flight. On the Archer the forward props transition horizontal but the aft props are fixed vertical. The Volocopter keeps all props vertical. And then there is the Jaunt that has a single main rotor with fixed horizontal props which will actually pursue Part 27/29 certification vs the new up and coming eVTOL rules.

[ATC Watcher]

I am following closely the Volocopter project as the firm that build them also build gliders ( the DGs) and mu clubs own few of the them , so i sometimes go to their factory and watch them.,
The first ones will have to be piloted, , The only model authorized to fly at the moment is the 2 seats 2X model, so only one paying pax. so the early economics based on autonomous flight for 2 paying pax is not there. Plus, unlike now with the prototypes, commercial operations means minimum CPL , so expensive pilots EASA has clearly said no difference for e-aircraft that for current ones,: 30 minutes reserves, which cut OPS range by 60-70% , next is secured Helipad or airfield to Helipad/airfield ,( some called Vertiports) not random front doors to office buildings. Fist live commercial operational ops planned next year Paris for the Olympics. Likely to be VFR ops only. On fixed special designated routes . Rules on overflying large number of people still unclear. Current trials flights in Pontoise airfield to validate the concept.
So in Europe at least , not that simple.

[what next]

I... commercial operations means minimum CPL , so expensive pilots ...

If you find pilots for that at all. Right now (in Europe at least) the airlines are again hiring and even in my sector, business aviation, we start to see a shortage in pilots. Unless you pay these people very well you won't get any. A very well paid pilot carrying one to three passengers at at time will make the operation quite expensive. And what about the times when these vehicles need recharging? In theory, you would need two aircraft per pilot - one that is flown and one that is being charged. Makes the operation even more expensive. In my view these things need to be fully autonomous in order to make any sense, at least commercially.

[EDLB]

In my view these things need to be fully autonomous in order to make any sense, at least commercially.

Yes. And the challenge is the first (propulsion/lift) failure case, when the automation needs to bring the craft safely down within 30 seconds or whatever time the crippled system has left.

[ATC Watcher]

Yes. And the challenge is the first (propulsion/lift) failure case, when the automation needs to bring the craft safely down within 30 seconds or whatever time the crippled system has left.
And not only how but where to bring it down in an urban area. Landing it on cars or on pavements full of people is not really an option.

[ETOPS]

Interestingly I've found there is already a "niche" airport shuttle operating from this Manhattan heliport. This is to EWR and uses conventional rotorcraft with a similar price structure - $195 - to the Joby propsal of around $200. Clearly using an old single engine Jetranger over New York is safer than new multi rotor eVTOLs....

[EDLB]

At least they can count on some proven water rescue services in the Hudson river. To my mind there is a similar Heli service in Las Vegas if your luck did hold up in the casinos.
So yes, there are some biz cases. If they are enough to pay the development costs, future will tell.

[hobbit1983]

ETOPS, do you have shares in an EVTOL company?

[ETOPS]

No - sadly I'm just a poor retired pilot :{

[bafanguy]

Variation on a theme:

https://simpleflying.com/leading-flying-car-companies-list/

[MarkerInbound]

But I am curious to know what the target demographic is for the pilots who'll be crewing the manned versions of the VTOL devices. And what will the training involve...rotor wing, fixed wing, vectored thrust ratings ?


The FAA currently has a “Powered Lift” category for pilot certificates but I don’t see any active certificates on the FAA pilot statistics page. Just a couple months ago they put out a NPRM to revise the training required and to require type ratings for all powers lift aircraft.

[jetpig32]

The FAA currently has a “Powered Lift” category for pilot certificates but I don’t see any active certificates on the FAA pilot statistics page. Just a couple months ago they put out a NPRM to revise the training required and to require type ratings for all powers lift aircraft.

I live 10 mins away from both Joby and Archers testing airports in California. Have acquaintances working at both. They will be power lift (only osprey pilots currently have that if the got their equivalency with FAA). The idea is to take a CPL or rotor pilot, and give them type training with a powerlift add on. They are targeting 500hr pilots (vfr 135 mins) who would use this to bridge the gap to 1500hr ATP, then they move on.

Archer would like to have this as part of the United Airlines Aviate ecosystem. the scheme as follows.
1) CPL at United aviate academy in Arizona (former Lufthansa).
2) Archer pilot for 1000 hrs. (Under United banner)
3) United Express pilot until 1000 PIC. (Mesa/gojet/commutair)
4)United Airlines Mainline

[jetpig32]

Also, a few years back FAA allowed powerlift pilots the ability to log count horizontal flight time as “airplane”. This largely benefited the osprey community who were having difficulty getting airline jobs due to CPL ATPL requirements.

[bafanguy]

Also, a few years back FAA allowed powerlift pilots the ability to log count horizontal flight time as “airplane”. This largely benefited the osprey community who were having difficulty getting airline jobs due to CPL ATPL requirements.

Just as an example, Delta is allowing Osprey pilots to combine their powered-lift time with fixed wing for application purposes. I don't see a reference to accounting for the portion of time in horizontal flight for the powered-lift pilots:

Minimum of 1,500 hours of total documented flight time. Minimum of 1,000 hours of fixed wing turbine time is preferred (airplane and powered lift combined). Minimum of 250 hours PIC or SIC as defined in 14 CFR §61.159(a)(5) in an airplane category.

https://www.delta.com/us/en/careers/pilots/hiring-faqs

[bafanguy]

Found this from 2019 from a Delta posting. At least they were thinking about it back then:

Announcing a change to our minimum pilot requirements!

Effective immediately, Delta will allow pilots of aircraft in the Powered Lift category (e.g. the V22 Osprey, AV8B Harrier, and F35B) to count 90% of your Powered Lift flight time toward our requirement of 1,000 hours fixed wing turbine time.

[Big Pistons Forever]

I think we absolutely need a separate forum so all the EVTOL BS Fantastical Bafflegab, and Brown rice news posts can be sequestered there and not take up space on real aircraft forums.

[Wizofoz]

Found this from 2019 from a Delta posting. At least they were thinking about it back then:

Announcing a change to our minimum pilot requirements!

Effective immediately, Delta will allow pilots of aircraft in the Powered Lift category (e.g. the V22 Osprey, AV8B Harrier, and F35B) to count 90% of your Powered Lift flight time toward our requirement of 1,000 hours fixed wing turbine time.
"Cause sitting keeping the wings level in cruise is MUCH more important than being in charge of a multi-million dollar aircraft during a difficult and skillful vertical take/off or landing- Sheesh!

[bafanguy]

"Cause sitting keeping the wings level in cruise is MUCH more important than being in charge of a multi-million dollar aircraft during a difficult and skillful vertical take/off or landing- Sheesh!

wiz,

I think the Delta hiring gods are slowly coming around to seeing that Osprey pilots might be able to fly a B-717. :)

Don't get me started on the hiring gods...

[tdracer]

I think we absolutely need a separate forum so all the EVTOL BS Fantastical Bafflegab, and Brown rice news posts can be sequestered there and not take up space on real aircraft forums.
Ah come on Big Pistons, stop mincing words - tell us how you really feel :E

[goeasy]

I think we absolutely need a separate forum so all the EVTOL BS Fantastical Bafflegab, and Brown rice news posts can be sequestered there and not take up space on real aircraft forums.

absolutely….. this site is for pilots. Non-pilots should go elsewhere on their own website!

[bafanguy]

absolutely….. this site is for pilots. Non-pilots should go elsewhere on their own website!

Won't some versions of these EVTOL machines involve an actual pilot...at least for some period of time ?

And how many EVTOL pilots are there so far ? Probably more to come.

[ETOPS]

Latest from Wisk

Wisk becomes first eVTOL air taxi company to conduct public flights in Los Angeles County, at Long Beach Airport, demonstrating the safety and reality of autonomous passenger flight



https://wisk.aero/news/press-release/wisk-flies-in-la/

[procede]

Not sure having flights 'at' Long Beach airport is going to attract a lot of passengers.

[bafanguy]

Not sure having flights 'at' Long Beach airport is going to attract a lot of passengers.

I can't imagine getting on that autonomous thing in the infancy of the technology. Nope...

[ETOPS]

flights 'at' Long Beach

​​​​​​​It was an air show demonstration

[bafanguy]

So even a US start-up airline is getting into the eVTOL thing ? Bold move:

https://worldairlinenews.com/2023/11/28/global-crossing-airlines-establishes-urbanx-air-to-pursue-urban-air-mobility-in-south-florida/

[Winemaker]

So even a US start-up airline is getting into the eVTOL thing ? Bold move:

https://worldairlinenews.com/2023/11/28/global-crossing-airlines-establishes-urbanx-air-to-pursue-urban-air-mobility-in-south-florida/

So where are these air-mobility flights going to land? You can't just hail a helicopter and have it land in the street. My brother has a house on Pine Lake in Sammamish, Washington. A neighbor wanted to use his helicopter to commute to work; neighbors were not happy that a whirlybird would be flying over for the benefit on one person. Result? VERY limited flights and times. How are these 'urban air mobility' flights expecting to pick up and drop off passengers? One can't simply drop from the skies and offload/upload passengers where ever one wants to..... This is not like a taxi or an uber.

My recollection is that helicopter transport to airport(s) from atop high rise buildings in New York proved not to be a good solution. How is this different?

edited to add: One crash and they will be gone.

[EDLB]

Ground transport on short distances will always be quieter, more energy efficient, safer, support higher people count and are more flexible on pick and drop locations than any air transport.
Air transport need to accelerate airmass down to support the weight of the craft. That is never real quiet for crafts with the necessary mass to transport people.
Add weather and safety then you know where the equation leans to.

[bafanguy]

So where are these air-mobility flights going to land? How are these 'urban air mobility' flights expecting to pick up and drop off passengers?

Heck if I know. I don't understand any of this. Maybe they'll build eVTOLports ?

[ETOPS]

Maybe they'll build eVTOLports ?

That's the plan - here’s the Beta Technologies version…

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/1400x1000/image_faa96e445cf82b10f84b69471b455039c36112af.jpeg
​​​​​​​

[Less Hair]

Doesn't seem to make sense to make people climb a ladder to board from a rooftop, as this is not an oil platform.

[bafanguy]

They sure are dedicated to getting rid of pilots ! :rolleyes:

[wrench1]

My recollection is that helicopter transport to airport(s) from atop high rise buildings in New York proved not to be a good solution. How is this different?
This is all an extension of a decades old concept called Urban Air Mobility (UAM). Recent technology breakthroughs with eVTOLS/VTOLs have merely re-emphasized this concept. One of the reasons UAM failed with helicopters was it wasn't "street-level" and had excessive noise. During the Heli-STAR ops for the Atlanta Olympics in the 90s, the street-level portion was further proven however there still was a noise issue with conventional helicopter. It was also the 1st real world test of ADSB which used the Heli-STAR helicopters and proved positive air space control in an urban environment was possible.

Given UAM has been around for so long, you'll find there are dozens of large cities globally that already have a UAM plan in place or in development. EASA and the FAA also have been working on UAM for just as long with the FAA using their Next-GEN platform for planning these infrastructures. The common factor with all these plans is that it will be street-level accessible and tie into other transport infrastructure. There are numerous reports, studies, and plans out in the public domain if you choose to read on it. Might also look for Advanced Air Mobility (AAM) and Regional Air Mobility (RAM) titles as UAM and RAM have been restructured under AAM on an international level. The one thing most miss on this concept is that it is not to replace existing aviation modes but augment them in areas that were not or could not be serviced by those existing methods. Interesting times ahead.

[mickjoebill]

The lilium pprune thread started in 2016 and forms a useful guide to the timeline of its development.
Last week it achieved a glowing report from EASA, which is linked in the last thread.


https://www.pprune.org/rotorheads/578979-lilium-vertical-take-off-jet.html#post9376365

Lilium published this video recently, aimed at investors, it is quite a good explainer on the core design hurdles in powering a electric vertical take off jet.

https://youtu.be/QgBp-YqZ_5M?si=QsuLL0lc-XwC-dHx
mjb

[ETOPS]

Here's a link to their latest video showing progress towards production of certifiable aircraft...

https://www.youtube.com/watch?v=_d_-VlbPna4

[ETOPS]

Wisk video detailing their traffic avoidance plans

https://youtu.be/_0Q3xig6KH4?si=iKNBdYOqdtOHPXpE

[lederhosen]

The autonomy video said what it intended to do but (as far I could see) not how it was going to do it. It talks about standard routes and automated collision avoidance and interface with ATC. But self driving cars seem to be taking a lot longer to get certified than earlier expectations and they seem an order of magnitude easier and less dangerous. For instance what happens in case of technical failure say an electrical glitch? I am sure all of this is solvable, just that when you factor in aviation and other authorities this is going to take a very long time till meaningful implementation.

[ETOPS]

The autonomy video said what it intended to do but (as far I could see) not how it was going to do it.

Take a look at this FAA paper..

​​​​​​​https://www.faa.gov/air-taxis/uam_blueprint

[ATC Watcher]

The noise aspect has been shelved and kept out of the debate, as many (wrongly) believe those electric aircraft will be silent. Well the engines are to a certain extend put the propeller blades are not, and multi high speed rotating props make an unpleasant high pitch noise. How the public , especially the people living under the routes will react and accept that new noise will be I believe one of the important acceptance factors ,

As to fully autonomous commercial operations, I just came back for a GNSS jamming/ spoofing meeting, and as long as this is not resolved I cannot see autonomous flights based on a GPS/GNSS infrastructure bring a viable option right now.

[ETOPS]

The noise aspect has been shelved and kept out of the debate, as many (wrongly) believe those electric aircraft will be silent. Well the engines are to a certain extend put the propeller blades are not, and multi high speed rotating props make an unpleasant high pitch noise

Nope - watch and listen to these flyover tests..

https://youtu.be/itP8-3j2UZI?si=r918y5_HH9hk4nDx

[ATC Watcher]

Very interesting indeed .Thanks . My bad then, with this type of technology at least using large propellers low speed. The couples of prototypes I saw and heard until now were all multi engines with small props turning at a few 1000 Rpms. , producing high pitch noises. One thing we must not forget : these urban vehicles will be flying low to very low.
Anyway next year in June for the Paris Olympics, the first ones are planned to be used. we'll then see the public reactions.

[jetpig32]

Nope - watch and listen to these flyover tests..

https://youtu.be/itP8-3j2UZI?si=r918y5_HH9hk4nDx

My brothers Baron is parked at Marina, CA, I wonder if that's his in the video. I have seen Joby test fly out there many times and it is truly a different sound. Until they flew manned last month, there would be a chase Cirrus 22 or R-44, and that's all you would hear. Now that it's doing manned flights, you can hear it, but it doesn't really draw attention. I have seen Archer as well out of Salinas in their smaller prototype. Seemed a little louder.
I will say, Joby appears to be well ahead of Archer Midnight. (unfortunately my airline put its money on the later)

[lederhosen]

The FAA paper adds some detail reinforcing the need for standard routes and also making clear that an onboard pilot plays a role certainly at least in the ramp up. Given that this will restrict payload and the standard routes will limit the points that can be connected I am intrigued by the business case and the demand side of the equation. Maybe I am too sceptical but this smacks of accounts I have read about the early days of the railways, eventually a huge success, but only after quite a lot of trial and error and rather a long time.

[wrench1]

The noise aspect has been shelved and kept out of the debate, as many (wrongly) believe those electric aircraft will be silent. .
I don't think the noise issue has been shelved per se as there have been dozens of studies and research papers done over the past 10 years specially to address the UAM noise patterns with a number of them published in various aerospace journals. They have even developed computer models to assist in mitigating those noise issues. Noise has been a top 3 problem for UAM going back to the 70s with most of the current noise studies getting their basis from the NASA Heli-Star noise study in the 90s. From what I've seen and read, if they can't provide an acceptable noise signature within the targeted urban environments it will go the same way helicopters went when they were used for UAM. However, it seems public perception of noise from a helicopter vs an eVTOL follows 2 different paths.

And while most of the up and coming eVTOLs/VTOLs will have the design capability for autonomous or remote piloted ops, I doubt there will be any pilotless pax ops in any reasonable timeframe. Cargo ops sure as they are currently testing this now with large drones. I think it will take another generation of people before enough of the general public will accept getting to the back seat with HAL driving up front.

[WillowRun 6-3]

New IATA document:

New Aviation Ecosystem Roadmap - IATA

https://www.iata.org/contentassets/c3f5994d248e45cb877774b41e7b3103/new_aviation_ecosystem_roadmap.pdf

[lederhosen]

Just read an article which referenced an academic expert in risk management at a leading German university and who previously worked in the flight safety department of a national airline. His argument in summary is that AI requires an incredible number of calculations to achieve true autonomy which even the fastest super computers cannot carry out in any reasonable time. The time required is currently not measured in minutes but millions of years so there will need to be some big breakthroughs.

[ETOPS]

there will need to be some big breakthroughs.

Yes - it's called Dojo...


https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1199x675/es1rodqhuf7b1_4fce9c8845ed02341128ce2a9477fe662265ceb8.jpg

[widgeon]

https://newatlas.com/aircraft/electra-estol-preorders/

Impressive order book if tru

[dixi188]

Have Lockheed licensed them the name?
Our Electras with 4 Allison 501 engines could be pretty short field when light.

[Big Pistons Forever]

https://newatlas.com/aircraft/electra-estol-preorders/

Impressive order book if tru

I find it amazing that all these companies can fund raise that kind of money on the strength of a YouTube CGI video. Don't investors do any research anymore ? So what if they did a short flight in what is basically a homebuilt bug smasher complete with lots of bumpy rivet heads ? That is a very, very ,very, long way from a viable 9 seat airplane that can go 200 miles with reserves in all weather.

If this thing is put into revenue service I will post nice things about Elon Musk on this site. You can hold me to it !

[20driver]

Compared to most of the electric schemes this one seems reasonable. What I could not figure out is how much if any batteries the plane carries. They say you do not need ground recharging so that implies all the power is coming from the on board ICE generator? Is fuel part of the payload ?

I agree this is a long way from anything that is useful and economic but it makes a lot more sense than lilium aviation which has managed to raise 1.3 billion! As for investors, aviation seems to make them totally ga-ga. As Warren Buffet said, "Indeed, if a farsighted capitalist had been present at Kitty Hawk, he would have done his successors a huge favor by shooting Orville down."

[ETOPS]

A little bit of digging shows the electric motors to be MAGicALL 75kW units.

https://www.magicall.biz/downloads/magidrive-datasheet.pdf

Thus with 8 installed the demonstrator has 600 kW available for take-off and - I'm guessing - MTOW of less than 2 tonnes.
Air intakes behind the centre section hint at a combustion engine to provide generated electricity for cruise and, apparently, the first test flight was electric only.
No duration given so will have to wait and see what batteries are carried.

[wrench1]

They say you do not need ground recharging so that implies all the power is coming from the on board ICE generator?
Its my understanding the 2 seat prototype uses a small conventional APU to provide normal flight electrical power. I believe the onboard batteries are enough to start APU, run things static, and provide enough power for an emergency landing. The 9 pax production version will have a Safran purpose-built "turbo-generator" with dual generators and most likely will burn SAF type fuel.

They are also pursuing Part 23 certification vs the current Part 21 exemption certification route as the eVTOLs are using which should make things much simpler and probably the reason for the influx of orders.

[Winemaker]

Its my understanding the 2 seat prototype uses a small conventional APU to provide normal flight electrical power. I believe the onboard batteries are enough to start APU, run things static, and provide enough power for an emergency landing. The 9 pax production version will have a Safran purpose-built "turbo-generator" with dual generators and most likely will burn SAF type fuel.

They are also pursuing Part 23 certification vs the current Part 21 exemption certification route as the eVTOLs are using which should make things much simpler and probably the reason for the influx of orders.
Then my understanding is this thing is not an EVTOL, it's a VTOL with electric motors for engines and a combustion engine(s) for power. This is not an electrical vehicle.

[wrench1]

Then my understanding is this thing is not an EVTOL, it's a VTOL with electric motors for engines and a combustion engine(s) for power. This is not an electrical vehicle.Its actually a STOL, short-take-off-landing, as there is no vertical TO component. Whether an “e” should go in front is up for discussion as are other terms like “rotor”, “prop”, etc. due to regulatory considerations. My guess in the end if it has an ICE onboard vs batteries or fuel cell to make electrical power it won't have the sought after "e" in front of the aircraft type. But who knows.

[petit plateau]

This is not EVTOL but is EV-flight. A very interesting read, with what looks to be much more sensible achievable engineering, and a pathway to staged development and economic operation within the existing eco-system

Dutch start-up Elysian breaks cover and pushes potential of all-electric 90-seater : Dutch start-up Elysian Aircraft claims newly published research supports its ambitious plan to develop an all-electric 90-seater for service entry in 2033, arguing that the potential for battery-powered aircraft has previously been significantly underestimated. Established last year, Elysian says the work carried out by its team – co-chief executive and chief technology officer Rob Wolleswinkel and director of design and engineering Reynard de Vries – alongside staff from the Delft University of Technology, signals a “paradigm shift in the potential for electric flight”.

https://www.flightglobal.com/air-transport/dutch-start-up-elysian-breaks-cover-and-pushes-potential-of-all-electric-90-seater/156431.article

Battery-electric aviation is commonly believed to be limited to small aircraft and is therefore expected have a negligible impact on the decarbonization of the aviation sector. In this paper we argue that, with the correct choice of design parameters and top-level aircraft requirements, the addressable market is actually substantial. To demonstrate this, the Class-II sizing of a battery-electric 90-seater is performed, and the environmental impact is assessed in terms of well-to-wake CO2-equivalent emissions per passenger-kilometer. The resulting 76-ton aircraft achieves a battery-powered useful range of 800 km for a pack-level energy density of 360
Wh/kg. For this range, it has an energy consumption of 167 Wh per passenger-kilometer and an environmental impact well below that of kerosene, eSAF, or hydrogen-based aircraft alternatives and comparable to land-based modes of transport. These results indicate that, to successfully reduce the climate impact of the aviation sector, battery-electric aircraft should not be designed as a niche product operating from small airfields but as commercial transport aircraft competing with fuel-based regional and narrowbody aircraft.

https://pure.tudelft.nl/ws/portalfiles/portal/173363843/de_vries_et_al_2024_a_new_perspective_on_battery_electric_av iation_part_ii_conceptual_design_of_a_90_seater.pdf

[Big Pistons Forever]

This is not EVTOL but is EV-flight. A very interesting read, with what looks to be much more sensible achievable engineering, and a pathway to staged development and economic operation within the existing eco-system

Dutch start-up Elysian breaks cover and pushes potential of all-electric 90-seater : Dutch start-up Elysian Aircraft claims newly published research supports its ambitious plan to develop an all-electric 90-seater for service entry in 2033, arguing that the potential for battery-powered aircraft has previously been significantly underestimated. Established last year, Elysian says the work carried out by its team – co-chief executive and chief technology officer Rob Wolleswinkel and director of design and engineering Reynard de Vries – alongside staff from the Delft University of Technology, signals a “paradigm shift in the potential for electric flight”.

https://www.flightglobal.com/air-transport/dutch-start-up-elysian-breaks-cover-and-pushes-potential-of-all-electric-90-seater/156431.article

Battery-electric aviation is commonly believed to be limited to small aircraft and is therefore expected have a negligible impact on the decarbonization of the aviation sector. In this paper we argue that, with the correct choice of design parameters and top-level aircraft requirements, the addressable market is actually substantial. To demonstrate this, the Class-II sizing of a battery-electric 90-seater is performed, and the environmental impact is assessed in terms of well-to-wake CO2-equivalent emissions per passenger-kilometer. The resulting 76-ton aircraft achieves a battery-powered useful range of 800 km for a pack-level energy density of 360
Wh/kg. For this range, it has an energy consumption of 167 Wh per passenger-kilometer and an environmental impact well below that of kerosene, eSAF, or hydrogen-based aircraft alternatives and comparable to land-based modes of transport. These results indicate that, to successfully reduce the climate impact of the aviation sector, battery-electric aircraft should not be designed as a niche product operating from small airfields but as commercial transport aircraft competing with fuel-based regional and narrowbody aircraft.

https://pure.tudelft.nl/ws/portalfiles/portal/173363843/de_vries_et_al_2024_a_new_perspective_on_battery_electric_av iation_part_ii_conceptual_design_of_a_90_seater.pdf

Did someone redo basic physics while I was asleep? Those performance numbers are nonsense.

[petit plateau]

Did someone redo basic physics while I was asleep? Those performance numbers are nonsense.

Can you point out what parts of the TUDelft paper are weak ?

I admit I did not expect to see such a study show such an opportunity existed in this timeframe, but the logic appears sound when I read it.

If indeed there are flaws in the calculations I am very interested to know more.

[Winemaker]

Can you point out what parts of the TUDelft paper are weak ?

I admit I did not expect to see such a study show such an opportunity existed in this timeframe, but the logic appears sound when I read it.

If indeed there are flaws in the calculations I am very interested to know more.
A quick calculation using the numbers in the article as to range, passengers, and battery energy density, suggests a battery to fly 800 km would mass about 33,500 kg. This does not include any reserve; with a 200 km reserve the mass is about 42,000 kg. One aspect of battery power is the landing aircraft weighs the same as the takeoff craft (with a tiny loss due to quantum effects that I will ignore). The kwh/passenger/km and energy density numbers also seem to be optimistic.

[petit plateau]

A quick calculation using the numbers in the article as to range, passengers, and battery energy density, suggests a battery to fly 800 km would mass about 33,500 kg. This does not include any reserve; with a 200 km reserve the mass is about 42,000 kg. One aspect of battery power is the landing aircraft weighs the same as the takeoff craft (with a tiny loss due to quantum effects that I will ignore). The kwh/passenger/km and energy density numbers also seem to be optimistic.

Thanks.

To be fair with a 76 tonne aircraft they themselves come up with a 35 tonne battery, so your 42-tonne calc (including reserve) seems to be in wild agreement.

As to the reserve fraction that is where they go with a gasturbine genset and liquid fuel so as to minimise emergency ordinarily unused weight. That is exactly the strategy I use when designing similar energy systems so I am not surprised by it. So that leaves 7 tonnes (your figure 42 - 35 = 7) of not-required reserve battery & liquid fuel. If you look at Fig 3 that looks to be about a 5% mass fraction, or 3.8 tonnes for emgy turbine + fuel, so a useful saving on your 7 tonne estimate. It seems your numbers are directionally in agreement with their numbers.

Are there any numbers that are identifiably plain wrong ?

[Winemaker]

Thanks.

To be fair with a 76 tonne aircraft they themselves come up with a 35 tonne battery, so your 42-tonne calc (including reserve) seems to be in wild agreement.

As to the reserve fraction that is where they go with a gasturbine genset and liquid fuel so as to minimise emergency ordinarily unused weight. That is exactly the strategy I use when designing similar energy systems so I am not surprised by it. So that leaves 7 tonnes (your figure 42 - 35 = 7) of not-required reserve battery & liquid fuel. If you look at Fig 3 that looks to be about a 5% mass fraction, or 3.8 tonnes for emgy turbine + fuel, so a useful saving on your 7 tonne estimate. It seems your numbers are directionally in agreement with their numbers.

Are there any numbers that are identifiably plain wrong ?
The best energy burn/passenger-km for conventional aircraft I could find was 259 wh/passenger-km (2.78L/100 passenger-km) and that number does account for inefficiencies of the engine, so I'm not sure how they arrive at the 167wh number; that's a massive improvement in flight energy consumption. An aircraft is an aircraft and a fuel burning machine will obviously reduce its weight as distance is traveled.

[Big Pistons Forever]

Guys help out this math challenged Biology major. So 76 tonnes = 167,000 lbs so even with a reasonable 10 lbs/hp power to weight ratio that is in round numbers 16,000 hp or 12,000kw of thrust. So assume 400 kph, 800 km no reserve requires a battery that can produce 24,000kw/ hr.

Is that even remotely possible even if the battery weighs 35 Tonnes ?

Finally how many electric cars can you make with 35 Tonnes worth of batteries?

[Winemaker]

Guys help out this math challenged Biology major. So 76 tonnes = 167,000 lbs so even with a reasonable 10 lbs/hp power to weight ratio that is in round numbers 16,000 hp or 12,000kw of thrust. So assume 400 kph, 800 km no reserve requires a battery that can produce 24,000kw/ hr.

Is that even remotely possible even if the battery weighs 35 Tonnes ?

Finally how many electric cars can you make with 35 Tonnes worth of batteries?
That's an interesting point. What is the power deliverable from a discharging battery looking at a charge/rate factor? If the battery is below say 25% charge, can it deliver at the same rate as a fully charged battery? What are the consequences for aircraft? Would it be necessary to look at a battery with 25% (number drawn out of the air) as less able to deliver energy to electric motors? How would this affect things such as reserve power and ability to do a go around?

[petit plateau]

Guys help out this math challenged Biology major. So 76 tonnes = 167,000 lbs so even with a reasonable 10 lbs/hp power to weight ratio that is in round numbers 16,000 hp or 12,000kw of thrust. So assume 400 kph, 800 km no reserve requires a battery that can produce 24,000kw/ hr.

Is that even remotely possible even if the battery weighs 35 Tonnes ?

Finally how many electric cars can you make with 35 Tonnes worth of batteries?

I will stay in metric for my sanity.

They do charge and discharge rate considerations in the paper, and it all looks plausible to me. Let us try some very crude ratio checks.
-------

There are 8 x 1.4MW electric motors on this design (continuous rating), which looks about right, so 11.2MW in toto.

For the 2nd gen aircraft they are using 440Wh/kg at pack level (table 3). So 35,000 x 440 = 15,400 kWh = 15.4 MWh

So at full throttle these motors could drain that pack in just over 1 hour (1.35h more precisely). That is entirely plausible and is similar to running a BEV automotive at max throttle.

For comparison a Tesla Model 3 has approx 82kWh and the motor in one variant is 137 kW, so at max power that could empty its battery in half an hour (0.59h).

So the aircraft is treating its batteries more gently than a typical automotive.
-------
15,400 kWh / 82 kWh = 188 cars worth of batteries.

For a 90 seater aircraft that looks about right, given the typical vehical seat occupancy fraction, and typical aircraft seat occupancy fraction.

[petit plateau]

I've done some further analysis after a colleague has kindly supplied some historical data. I can combine that with my own database to figure out the energy density improvement trends vs cumulative cell production, which is a fairly standard way of analysing learning curves.

We can say that as an approximation the pack level automotive mainstream energy density in high volume commercial use is approximately half of the most advanced individual cell level density released for purchase.

So today the cutting edge cell is at ~700 Wh/kg (cell) and the leading mainstream use is ~ 300-350 Wh/kg (pack). Clearly one can pay extra and push up the price/performance curve at any given moment. The aircraft designers themselves make that point.

Looking ahead the technology improvement slope on energy density seems fairly linear trend. That is likely because power density is the priority mainstream performance metric that is being pursued, and (without looking at data) that is likely a power law trend. The current energy trend appears to be approx. 133 Wh/kg per 1 TWh cumulative increase. So the current 2.5TWh cumulative corresponds to the 700 Wh/kg peak cell or the 350 Wh/kg avge pack. Therefore the 10 TWh cumulative corresponds to 1700 Wh/kg peak cell, or 850 Wh/kg avge pack. The 2.5 TWh is 2023, and the 10 TWh is likely to be 2028.

So the proposed design is indeed sensible in the context of the 2030s timeline they have in mind. They have done this cell learning curve analysis themselves even if it is not explicitly written down in their paper.

[Big Pistons Forever]

188 electric cars would presumably replace 188 ICE cars. Wouldn’t the net environmental benefit be much higher than replacing one 90 seat short haul airliner powered by fossil fuels with an electric version ?

[petit plateau]

188 electric cars would presumably replace 188 ICE cars. Wouldn’t the net environmental benefit be much higher than replacing one 90 seat short haul airliner powered by fossil fuels with an electric version ?

It is possible to do both. It is beneficial to do both. And in this instance doing both in parallel is approximately equally environmentally beneficial. (There are no constraints apart from $$$capital and solving the 10 or so challenges that the paper sets out - there seems to be no unobtainium in there)

From an aviation industry perspective it is better to get such an airliner into service as soon as possible. Absent such an airliner the high speed rail networks will expand to cover a greater network than if such an airliner exists. Once high speed rail networks exist, then the ability of an airliner to get back into competition on those routes is very much more difficult. So for the benefit of both the operating part of the industry (airports, flight crews, etc) and the manufacturing part of the industry (airframers etc) it is better to push ahead with such projects faster rather than slower. Especially given that this airliner is aimed at the edge of the viability zone of the high speed rail network (4h rail vs 2-3h flight + airport).

(This is an entirely different commercial segment than the airtaxi EVTOL one, which requires a new business model to become viable, as well as new products. This aircraft satisfies an existing viable business model. That is a huge risk reduction).

That is why this is such a fascinatng paper.

[wrench1]

This aircraft satisfies an existing viable business model. That is a huge risk reduction).
True. But if you take the current business model and existing aircraft but utilize 100% SAF fuels in those aircraft then there would basically be no risk. So how would that compare to this new electric airliner in your opinion?

[KiloB]

Lots of interesting formulas in this Thread, but the most applicable formula for battery-powered-airliners is probably:

PONZI = number of investors x average contribution
1/no. of years it can be dragged out

I might be wrong, but time will tell.

[procede]

While I believe the design is technically possible, I see few issues:
800km still does not make the aircraft versatile enough for most airlines. It can only serve a limited number of routes, compared to the already lacklustre Q400, which has more than twice the range. Also see Dassault Mercure.
Fully draining the batteries will wear them out very quickly. Normally you should not drain them below 20%, leaving the rest only for reserve.
Charging them to 100% means a turnaround of at least 1.5 hours. Not ideal for scheduling or crew planning. Making 36 tonnes of batteries in the wing replacable on the stand is not realistic.

[petit plateau]

True. But if you take the current business model and existing aircraft but utilize 100% SAF fuels in those aircraft then there would basically be no risk. So how would that compare to this new electric airliner in your opinion?

The paper does look at that. Drop in liquids are in my opinion an illusion being deployed for distraction. But even if they were to become available at quantity then they are very costly. I expect them to get reserved for long range transoceanic and military, and other niche applications - driven largely by high costs. So whilst capex of running on existing design types with dropins is low, the opex is high. So first mover takes the risk but gets a good reward, unless of course simultaneous first movers emerge in the airframers.

While I believe the design is technically possible, I see few issues:
800km still does not make the aircraft versatile enough for most airlines. It can only serve a limited number of routes, compared to the already lacklustre Q400, which has more than twice the range. Also see Dassault Mercure.
Fully draining the batteries will wear them out very quickly. Normally you should not drain them below 20%, leaving the rest only for reserve.
Charging them to 100% means a turnaround of at least 1.5 hours. Not ideal for scheduling or crew planning. Making 36 tonnes of batteries in the wing replacable on the stand is not realistic.

The study looks at the cyclic life and charge times, both of which fit with 45-min turnarounds and 1/year hangar maintenance.

Routes and flexibility would be an issue if up against an unconstrained opposition. But if up against expanding TGV network (and EV users) at bottom end; and drop-in liquids at the top end, then it begins to look very advantageous.

The technology growth curve graph for battery energy density doesn't need to hit a brick wall in 2030 at 10TWh cumulative, further improvements are possible. LHR-ATH is realistic in that timeframe, which serves a lot of the market.

[wrench1]

Drop in liquids are in my opinion an illusion being deployed for distraction. But even if they were to become available at quantity then they are very costly. I expect them to get reserved for long range transoceanic and military, and other niche applications - driven largely by high costs.
Interesting, except you have to put this into context. SAF mixtures have been commercially flying for a number of years. However, only 50% SAF mixtures are currently approved with 100% SAF usage currently in the approval process to include its use on revenue flights.

As to cost, yes its currently about 2x the cost Jet A but the full market won’t be realized until 100% SAF usage is certified. Once that happens then you see both production increase and cost lower as projected. For example, SAF now accounts for about 2% of the Jet fuel market, up from .01% in 2019. And the yearly SAF production increase forecasts are now about 3% higher than Jet fuels yearly increases at 1%.

Plus those numbers are mainly for Part 121 ops. The Part 135, rotorcraft, and hybrid markets are still working out details as there is no feasible route forward until SAF achieves 100% certification. So while it may appear as an illusion, SAF has been flying in the real world for quite some time vs a drawing on paper.

In my experience, I believe SAF usage and hybrid ICE aircraft will fill the “void” vs a true e-aircraft at the “mass” transport level for years to come. At the UAM and RAM levels it’s a different dynamic and more fits the e-side of the equation.

[Big Pistons Forever]

Pushing up against the edge of what is predictably possible in battery technology gets you a short haul Regional airliner. Its effect on the reduction global emissions will so low as to be negligible. It is purely an exercise in green virtue signalling, hence my comment that using the rare earth metals on 200 cars per airplane actually makes more sense.

Yes commercial aviation has to do its part and the obvious way is with SAF, that is where development money should go, not on electric airliners.

I have a part time gig working on electric airplanes for flight training. They are IMO the future of flight training not because they are green, although that’s nice, but because the typical training duty cycle fits the capabilities of electric power and because their fly over noise footprint print is 10 db less than a typical ICE training aircraft and most importantly they will succeed because the economics are going to favour them. Not using expensive Avgas creates huge savings and the running maintenance cost are about %20 of an ICE airplane.

So what is the cost per seat mile of this electric 90 seat airliner and how does it compare to an equivalent Turbo Prop airliner ?

[petit plateau]

Interesting, except you have to put this into context. SAF mixtures have been commercially flying for a number of years. However, only 50% SAF mixtures are currently approved with 100% SAF usage currently in the approval process to include its use on revenue flights.

As to cost, yes its currently about 2x the cost Jet A but the full market won’t be realized until 100% SAF usage is certified. Once that happens then you see both production increase and cost lower as projected. For example, SAF now accounts for about 2% of the Jet fuel market, up from .01% in 2019. And the yearly SAF production increase forecasts are now about 3% higher than Jet fuels yearly increases at 1%.

Plus those numbers are mainly for Part 121 ops. The Part 135, rotorcraft, and hybrid markets are still working out details as there is no feasible route forward until SAF achieves 100% certification. So while it may appear as an illusion, SAF has been flying in the real world for quite some time vs a drawing on paper.

In my experience, I believe SAF usage and hybrid ICE aircraft will fill the “void” vs a true e-aircraft at the “mass” transport level for years to come. At the UAM and RAM levels it’s a different dynamic and more fits the e-side of the equation.

Valid points.

Yes, I appreciate that SAF has been around is working its way through the approvals process. I mean at scale and at an economic price. That means that bio-SAF is excluded as that cannot scale sufficiently (imho). Leaving e-SAF from renewables for large scale utilisation. The ins vs outs table is pretty clear where that is likely to go. I fully accept that small amounts of bio-SAF will be flying but personally I am sceptical regarding large scale adoption. We will see.

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/812x566/image_f7db5e245605a2310b8e086b4d2f35ec73e1778e.png

Pushing up against the edge of what is predictably possible in battery technology gets you a short haul Regional airliner. Its effect on the reduction global emissions will so low as to be negligible. It is purely an exercise in green virtue signalling, hence my comment that using the rare earth metals on 200 cars per airplane actually makes more sense.

Yes commercial aviation has to do its part and the obvious way is with SAF, that is where development money should go, not on electric airliners.

I have a part time gig working on electric airplanes for flight training. They are IMO the future of flight training not because they are green, although that’s nice, but because the typical training duty cycle fits the capabilities of electric power and because their fly over noise footprint print is 10 db less than a typical ICE training aircraft and most importantly they will succeed because the economics are going to favour them. Not using expensive Avgas creates huge savings and the running maintenance cost are about %20 of an ICE airplane.

So what is the cost per seat mile of this electric 90 seat airliner and how does it compare to an equivalent Turbo Prop airliner ?

Valid points.

The research paper is pretty silent on the seat mile cost issue. The Capex side of the equation is not mentioned, nor is the maintenance opex. The only thing one can directly inspect in the paper is the relative fuel (energy) usage. Given that fuel is a large cost driver it does not look impossible. Crew etc would be approximately equal in most cases. Regarding maintenance most things would be fairly equal, but combustion engine/fuel system (etc) maintenance costs would be almost entirely eliminated, and annual battery replacement costs would need to be factored in. How that might all net out I do not know. Maybe that is the 3rd paper in the series, but perhaps one has to sign an NDA to read it. Certainly it is critical as you point out.

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/804x473/image_99fd60a7542af11364dd5793f9b1435315e3f227.png

[kiwi grey]

So what is the cost per seat mile of this electric 90 seat airliner and how does it compare to an equivalent Turbo Prop airliner ?
That will depend almost entirely on fuel cost assumptions:

Battery electric: the battery will probably be semi-consumable, with a limited number of cycles, so it's "fuel" of a sort. How many cycles/years?
Fuel-cell electric: cost of hydrogen fuel - I don't think anyone has now a clear view of the likely costs of bulk supplies of green LH2 in the 2030s & 2040s
Hydrogen-fuelled turboprop: cost of hydrogen fuel (see above)
SAF conventional turboprop: will the SAF be 1.5x, 2x, or 3x the 2024 cost of fossil fuel?
Fossil-fuelled turboprop: cost of fossil fuel. I expect this will probably be still available until 2050-ish, but I expect carbon taxes to make this more and more expensive, then eye-wateringly more expensive, at least in "Western" nations.

Electric propulsion aircraft should be a bit cheaper in maintenance costs than turboprop aircraft, because there a so many fewer components - particularly rotating components - in their engines, but I doubt this will be significant in the whole picture.

[wrench1]

I fully accept that small amounts of bio-SAF will be flying but personally I am sceptical regarding large scale adoption. We will see.While you may be skeptical, the industry is scaling up with a projected increase of 40-50% by 2030. SAF demand is outstripping current production even at the 50% certification level, so there are about 18 new SAF production projects in progress in the US alone with the majority of that future production already under contract.

Regardless, even if 100% SAF approval stays on schedule, the one limiting factor will be SAF production capacity for the next decade. However, as you stated, we will see.

[Winemaker]

That will depend almost entirely on fuel cost assumptions:

Battery electric: the battery will probably be semi-consumable, with a limited number of cycles, so it's "fuel" of a sort. How many cycles/years?
Fuel-cell electric: cost of hydrogen fuel - I don't think anyone has now a clear view of the likely costs of bulk supplies of green LH2 in the 2030s & 2040s
Hydrogen-fuelled turboprop: cost of hydrogen fuel (see above)
SAF conventional turboprop: will the SAF be 1.5x, 2x, or 3x the 2024 cost of fossil fuel?
Fossil-fuelled turboprop: cost of fossil fuel. I expect this will probably be still available until 2050-ish, but I expect carbon taxes to make this more and more expensive, then eye-wateringly more expensive, at least in "Western" nations.

Electric propulsion aircraft should be a bit cheaper in maintenance costs than turboprop aircraft, because there a so many fewer components - particularly rotating components - in their engines, but I doubt this will be significant in the whole picture.
A couple of comments. Re hydrogen fueled turboprops, the issue with hydrogen is storage; tankage, whether liquid or gaseous will require a pressure vessel as normal wing tanks are sealed areas in the wing structure. Volume is a huge (ha ha) issue also, as the energy density of hydrogen/volume is low compared to jet fuel. Yes, n a weight/energy analysis hydrogen is great, but on a volume analysis it falls down vs jet fuel.

Also, hydrogen production is and issue; most hydrogen is now produced by a steam process breaking down natural gas, this requires more energy input than the fuel produces when used. Yes, if there were a large infrastructure of solar cells hydrogen could be produced by electrolysis, but if there weren't (and there isn't) electrolysis would require electricity generated by some sort of power plant, again negating any energy advantage of hydrogen. I won't go into the numbers here, but hydrogen fueled passenger aircraft just don't pen out.

[ETOPS]

Maybe Gold Hydrogen is the answer?

https://www.newscientist.com/article/mg26134760-500-the-gold-hydrogen-rush-does-earth-contain-near-limitless-clean-fuel/

[ETOPS]

Latest Archer e-VTOL test flight video..


https://youtu.be/QB7nS4zYB5M?si=Ia9RmzhHgnppdY8a

[ETOPS]

Joby Aviation press release about Dubai operation

​​​​Santa Cruz, CA, and Dubai, UAE, Feb 11, 2024 — Joby Aviation, Inc. (NYSE:JOBY), a company developing all-electric aircraft for commercial passenger service, today announced it has signed a definitive agreement with Dubai’s Road and Transport Authority (RTA) to launch air taxi services in the Emirate by early 2026, with Joby targeting initial operations as early as 2025.​​​

Whilst I fully agree that this is a bit “showcasing” by Dubai it will, nevertheless, give Joby a real world test of their capabilities. A number of rotations around these short hops without recharging should reveal actual endurance and operability.

https://www.jobyaviation.com/news/joby-to-launch-air-taxi-service-uae/

[Winemaker]

Joby Aviation press release about Dubai operation



Whilst I fully agree that this is a bit “showcasing” by Dubai it will, nevertheless, give Joby a real world test of their capabilities. A number of rotations around these short hops without recharging should reveal actual endurance and operability.

https://www.jobyaviation.com/news/joby-to-launch-air-taxi-service-uae/
An issue here is what market will this serve? Most airlines passengers are not rich persons able to afford the luxury of an EVTOL ride to where ever, they are people visiting relatives or going on vacation et al. My point is that the development and implementation of these aircraft, which honestly seems unlikely by the numbers, benefits and serves a very small portion of the traveling public. Yes, electric craft would be nice assuming the infrastructure for generating the electricity to power them is some sort of green generation, but with 83 million passengers in the US last year, what impact will these possible craft have on fuel consumption vs driving to the airport? Seems like a rich persons limo.

[ETOPS]

An issue here is what market will this serve?

It's Dubai - think of it as a very complex fairground ride.

Seems like a rich persons limo.

Probably cheaper than some of the posh cars seen along the Sheikh Zayed Road!
But seriously this will get the concept and operation moving forward just like the Paris Volocopter shuttle at the Olympics.

[wrench1]

An issue here is what market will this serve?
The UAM market, which has been around for decades but had no viable vehicle/aircraft to serve it at the street level until. That is until the eVTOL technology evolved to its current level. There are a number of large metropolitan areas globally that have had a UAM plan ready for years. Now those plans are being dusted off and put into place.

As to cost, I believe the target for a number of eVTOL providers is the similar to Uber Black costs which I think is around $7.00 USD per mile. But I believe your pax number is a bit low. UAM will not change the existing spoke and hub system, it will merely supplement that system with a new level of service that will be easily accessible to many more people. So the projected usage numbers are in excess of the 83M in the US with higher percentage increases overseas.

If you want more details there are plenty of AAM, UAM, and RAM studies out there with the EASA and FAA having some in-depth ones.

[EDLB]

IMHO it will go the same route a SST. Remember the Boeing 2707 or Concorde. For an enormous amount of money and noise you create a relative small advantage. In the end the market will decide. It competes with a taxi ride. Transport time to the airport is in todays world the lesser time eater. Those seconds you gain will be lost standing in the TSA security check in line anyway.

[ETOPS]

Transport time to the airport

As wrench1 mentions above the Urban Air Mobility plans don’t necessarily involve airport transfers.

Think about a drive from Simi Valley to anywhere in the east side of the Inland Empire versus a quick hop in a flying Uber….

[ETOPS]

Have to admit I'm not 100% familiar with this design by Skydrive but their latest press release contains some fairly important backing from Suzuki..

Japan – March 7, 2024 – SkyDrive Inc., a leading Japanese eVTOL (*1) aircraft manufacturer, today announced the start of production of its highly anticipated “SKYDRIVE (SD-05)” (*2) aircraft at Suzuki Motor Corporation’s (“Suzuki”) manufacturing plant in Iwata-city, Shizuoka, Japan. This marks a significant milestone in SkyDrive’s mission to revolutionize urban air mobility.

The first riveting ceremony took place on March 6, 2024, attended by Toshihiro Suzuki, Representative Director and President of Suzuki, Tomohiro Fukuzawa, CEO of SkyDrive, all employees from Sky Works and other representatives. The ceremony marked the beginning of production and served as a symbol of the collaboration between SkyDrive and Suzuki.


https://en.skydrive2020.com/archives/12380

https://en.skydrive2020.com/

[ETOPS]

Here's a video of a recent demo flight by yet another Chinese eVtol company call Autoflight. It's a 50km point to point from Shenzen across the Zhujiang River Estuary to Zhuhai - basically following the northside of the route of the Hong Kong- Macau bridge.

https://www.youtube.com/watch?v=xSUvx5cldBU

[AeroAds]

I can’t post the link as I’m a new user but if you Google "The age of the flying taxi draws closer with the Future of Flight action plan” you’ll see that GOV.UK are throwing money at EVTOL.“Flying taxis, crime-fighting drones and critical 999 care deliveries could all be a reality by 2030 thanks to the government and industry’s joint Future of Flight action plan, announced by the Department for Transport (DfT) today (18 March 2024).

Setting out a roadmap for drones and novel electric aircraft in the UK, the plan details how technology once confined to the realm of sci-fi could transform our skies, with studies estimating drone technology could boost the UK economy by £45 billion by the end of the decade.

It details plans for the first piloted flying taxi flight by 2026 and regular services by 2028, regular drone deliveries across our skies by 2027 and demos of autonomous flying taxis without pilots on board by 2030 – transforming how people and goods are transported."

[Lonewolf_50]

Here is the link.
The age of the flying taxi draws closer with the Future of Flight action plan - GOV.UK ( (https://www.gov.uk/government/news/the-age-of-the-flying-taxi-draws-closer-with-the-future-of-flight-action-plan)www.gov.uk)

[ETOPS]

For the past 5 years Beta Technologies have been developing their Alia EVTOL - at a deliberately careful pace. This short, simple video details a very important point in their progress which is the first full transition flight. Whilst not a "Wright brothers" moment I believe it sets them forward to full flight testing and ultimately production.

https://www.youtube.com/watch?v=N1N2BFLY4cA

[ETOPS]

E-Hang in China now have some form of "Type certificate" for their 2 seat EH-216 model. This video gives a pretty good overview of progress - watch near the end for a mass take-off!

https://www.youtube.com/watch?v=XBCq6JGKqUg

Couldn't help noticing the "boss" didn't avail himself of the demo flight :rolleyes:

[netstruggler]

E-Hang in China now have some form of "Type certificate" for their 2 seat EH-216 model. This video gives a pretty good overview of progress - watch near the end for a mass take-off!

https://www.youtube.com/watch?v=XBCq6JGKqUg

Couldn't help noticing the "boss" didn't avail himself of the demo flight :rolleyes:

Getting in and out looks a bit hairy. I wouldn't be happy walking through those blades knowing there's someone in a control room 10km away who could start them up.

[Maoraigh1]

Is this relevant to this thread? UK or Scottish public money likely. I wonder what wind limitations it will have.
"https://news.stv.tv/highlands-islands/electric-aircraft-airlander-10-reserved-for-highlands-and-islands-as-plans-progress?utm_source=app