The largest electric aircraft just flew [video](youtube.com) |
The largest electric aircraft just flew [video](youtube.com) |
I will never fly on any aircraft that does not have a minimum two-person crew on the flight deck. The ability to "feel" the plane is invaluable in an emergency situation. Frankly, just the fact that someone whose life is literally on the line doing the walkaround is an invaluable part of the safety of commercial flight.
I was rooting for this company when I saw the news of their first flight. I am no longer rooting for them because it is obvious that their leadership does not understand the human element of commercial air travel.
You're missing out. Flying solo in a small plane is great.
More of a replacement for the "helicopter market"...
One of the ways to achieve high thrust at low tip speed is to have larger total propeller surface. The best shot of the propellers is around 9s and these don't look like particularly large propeller blades, but there are 20 propeller blades compared to 8-12 that you might see on a 50-ish seat turboprop airliner.
But it's unlikely to ever be quiet to lift 20 tons into the air.
Filling a wing with helium would barely shift the weight of the plane measurably. Filling the cabin and cockpit would be bad for what I hope are obvious reasons...
I'm not an engineer, probably it is more reasonable to fill the remaining space with battery ;)
Uh, what about the Bombardier C-series (A220)?
Hence 18 years.
SAS?
Most of the video is the workshop.
Where is the airplane??
They need to hire an actual designer, if the plane weighs 0.5% more but has actual human usability that's worth it.
BUT, where current aircraft are usually constrained on size, cramming as many passengers as possible into the cabin is the goal.
Here, space will be less of an issue than weight. So cabins can offer more room between seats minimalist seats.
related : many flight demonstrators in the past for large passenger planes have had no interior at all aside from the cockpit and ballast kits.
A new approach required new thinking about everything involved, including takeoff and landing. They didn't do that; that's why they ended up with the compromise of a hybrid. It was a sign, and they ignored it and went ahead. Imagine a design that requires - no traditional landing and takeoff, including no ATC; some electric planes are already built around that, but sadly not this one.
Also, helium requires airtight containment - which itself would add weight.
Not belittling you; trying to explain the problem better for you.
It being barebones from the factory is not a problem.
The competition in this market segment doesn't look like Middle Eastern airlines' first class cabin concept art, it looks like this: https://en.wikipedia.org/wiki/Saab_340#/media/File:Mesaba_Ai...
The founder seems to sneak in the word "hybrid", around 1m30 mark in the video below.
https://youtu.be/nM86DBOqgPM?si=5unXLmPxk6M_kmuN&t=86
Note: not being negative, I just want to ensure I understand correctly since the title might imply something else.
Update: confirmed, it does use aviation fuel.
> "The airplane will also include a reserve-hybrid configuration, consisting of two turbo generators powered by sustainable aviation fuel. The reserve-hybrid system is installed to secure reserve energy requirements without cannibalizing battery range, and it can also be used during cruise on longer flights to complement the electrical power provided by the batteries."
https://www.heartaerospace.com/newsroom/heart-aerospace-unve...
He cannot make them work if he has to store enough battery to fly around for an additional hour or two searching for an airport to divert to in an emergency, which is an FAA requirement.
So he has the heavy battery bank for regular trips costing almost nothing per flight-hour, and the expensive fueled backup system for emergencies.
Smaller, lighter, simpler, cheaper, and more flexible about fuel.
https://www.youtube.com/watch?v=NeG4zLlFkak
Linear engine starts around 11:19
The way modern hybrids can charge from an outlet, I classify them as EV-Hybrid, and only use gas if need be vs older ones that only charge through the gas engine, Hybrid.
Jet fuel has a specific energy of 12 kwh/kg and a density of 6.7 lb/gal (2). So 80 gallons of jet fuel is 536 lb, or 243 kg, and contains 2,916 kwh of energy. Jet engines are not very efficient, so lets say only 30% of this energy actually ends up being used. So 875 kwh.
Lets say we are using batteries that are 300 wh/kg (0.3 kwh/kg), which seems on the high side of what electric cars are using now (and that there are no efficiency loses in the electric motors or elsewhere).
Now maybe I messed up my unit conversions but I think that means to carry the same energy onboard you would need 6,428 lbs of batteries. And you are still going to carry atleast 1,600 lbs of fuel on top of that. And you have the weight of both electric and conventional engines.
I could see this reducing costs like they say but when many big costs are fixed (pilot, hangar, etc.) will this actually make sense? Will airlines fly something that has thousands of pounds less payload than a competitor but lower running costs? I don't know but it will be interesting to see.
(1) https://airinsight.com/seat-miles-gallon-fuel-burn-update/ (2) https://en.wikipedia.org/wiki/Jet_fuel
Cheap electric transportation can finally offset USA's lacking rail commutes and attack Europe's short flight market (which is already cheap). Now we need bigger planes or more frequent planes and the next startup to solve the energy needs.
"Half of all flights in the world are under 2 hours." Then they give examples of Fjord-town hopping in Norway, or Island hopping in Hawaii, which seem very niche.
Will they be able to compete in any of the busiest routes? Could it take me Melbourne-Sydney in 1 - 2 hours for < $100? I'd sacrifice some time and $ for an eco-friendly option, but obviously there's a limit.
https://en.wikipedia.org/wiki/List_of_busiest_passenger_flig...
Still an incredible feat, but no idea where the $5 comes from. Maybe that’s just the power they use to get from the threshold of the runway to wheels up.
To be fair though it is more likely to be 50 kWh just for the take-off, so that's probably where their $5 figure came from (at $0.10 / kWh). For comparison: a single gallon of Jet-A = ~150MJ. 320 kWh = 320,000 W for one hour so 3600 * 320,000 = 1150MJ, or about 40 gallons and I suspect that these electric motors are quite efficient.
So it does pencil out, I think. Or maybe my pencil is broken and no doubt HN will correct my math.
This is the statement that matters and why I think electric is a huge deal. We can't get new designs into the air. It costs too much and takes too long. Electric has the potential to bring the design cycle back to something reasonable. Electric engines, and the supporting systems around them, are just so much simpler so there is so much less to certify. Once we really start designing for electric, and iterating on those designs, I think we will start seeing massive gains very rapidly.
https://www.wired.com/story/magnix-electric-plane-motor/
So much simpler.
They seemed to have a lot of former Embraer engineers from Brazil, I wonder if they brought them over to the US.
> Heart warned that Europe needed to respond to the U.S. Inflation Reduction Act if it wanted: “to retain technology companies like Heart within the EU”
2 years later:
> "We are deeply grateful to our team in Sweden for being part of this chapter of Heart’s journey, and for all the support we have received in Sweden," said Anders Forslund. "However, as our customers, partners, and investors are increasingly based in the U.S, we see greater opportunity in focusing our resources here. By consolidating our operations in Los Angeles, we can accelerate development, strengthen collaboration, and better position Heart Aerospace for the future."
Looks like a combination of regulatory and business/operations made USA more attractive.
[1] https://www.regeringen.se/contentassets/0a5c91ad1a1c4fdaaefb... (PDF)
[2] https://www.heartaerospace.com/newsroom/heart-aerospace-relo...
Grid Battery seemed to mostly survive but not sure if there's as much crossover there as with EVs.
Companies like Joby, Archer and others also seem to be taking the huge gamble that battery density in Watt-hours per kilogram will SIGNIFICANTLY increase in the next 5-10 years (before they run out of money/investors) making the range of their aircraft much greater, and more viable for commercial operation.
The electric VTOL companies in this niche that survive may ultimately end up with something like a small series hybrid that uses Jet-A fuel and has a single gas turbine engine driving a generator, along with batteries, and electric propulsion motors.
Electric motors and gas turbine in use to lift off, consistent lower fuel consumption gas turbine -> electrical use during level cruise flight, then another burst of amperage and use of batteries during the landing phase.
Also, most countries are not that large. If we ignore the top 10 largest by area, possibly most of the domestic flights can be served.
On another note, other than the struts, the design is reminiscent of the DHC Dash-7, a STOL airliner from the '60s that also used slower propellers (with gearing instead of an electric motor, of course) to reduce noise. That plane wasn't particularly fast either (240kts max speed).
I guess an additional advantage in this design is that the weight of the batteries is in the fuselage rather than the wing, so additional strengthening of some type may be necessary in either scenario.
While poking around their website to try and find good still images from a top-down angle of their demonstrator, I did notice that there is no bracing in the concept images of the ES-30, for whatever that is worth.
Unfortunately as the crow flies that seems to be closer to 800 miles than 125.
I'm in London and the airport itself is already 60 miles away.
The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected): https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery
https://en.wikipedia.org/wiki/NASA_Pathfinder
https://en.wikipedia.org/wiki/AeroVironment_Helios_Prototype
Wingspans basically double at 200+ feet across.
Range: 125 miles all electric
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500 miles with hybrid system (electric + conventional turbo prop)The higher reliability of electric.
Losing an turbine engine doesn't mean asymmetrical thrust. Plane still flies normally.
Losing an engine on takeoff you still have full power.
Electric motors spin up faster than turbines. Which means faster throttle response. Which you need when hit with a wind shear on landing.
Take off and landing under electric power means much less noise.
Efficiency, you can increase the number of props or fans to get a much higher bypass ratio. Worth noting the plane in the video has four props.
If this is a hybrid, I am curious where they are stealing energy from.
Is it still competitive?
Can we realistically get lots of it, like ever?
Synfuel made just from air and electricity is doable (both water and carbon dioxyde can be extracted from the atmosphere). And with 10% of what's spend on IA we'd be way out of the lab...
Thankfully there are military budgets (synfuel makes sense on a nuclear carrier)
Cool stuff regardless!
This plane basically has to outperform a Saab 340.
Fixed wing commercial airliners generally don't, because airlines' biggest cost is fuel and new aircraft are a lot more efficient than older ones
Seems optimistic to think that a first generation electric plane will avoid that challenge: in theory if you're only operating on electricity the kinetic efficiency doesn't matter quite so much, but 125 miles range on electric power is really quite limiting and crucially newer generation electric aircraft would be expected to offer more electric range. I guess a lot might depend on how easily it is to legally retrofit better batteries to older gen aircraft.
They'll want to sell for more than the market value of an old Saab 340, that's for sure...
If anything, planes have real autopilots!
[0]: https://www.businessinsider.com/musks-claim-teslas-appreciat...
But the drone explosion, the economies of scale around electric power, are very attractive.
Of course the biggest unlock in the whole equation is a fully autonomous flight computer.
then we are not tied to global fuel politics
and maybe airports will become far less toxic with leaded fuel finally being completely eliminated
(and there is a Ycombinator video channel? never knew)
Things seem to go in the right direction, with an unleaded alternative in the process of being certified. But aviation, especially general aviation moves at a glacial pace, usually for good reasons, maturity is important, but not poisoning people is important too.
https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...
In terms of operating cost, not just cost of fuel, but if the electric engines can be much less costly in terms of periodic maintenance and overhaul. Maintenance and overhaul costs on turboprop and small jet turbine engines are not cheap.
There are opportunities for which airplanes have never made economic sense because they have big fixed costs like pilot, hangar, fuel-infra, engine(-maintenance). So will small short haul (?pilot-less) rechargeable planes have enough allure to beat out alternatives where planes were never considered before?
probably not at any major scale in a future where it competes with other autonomous transport, but that's me guessing at numbers. There will be enough of a market to build these things for niche constraints (eg the fuel-infra if small modular reactors become widespread).
Even a farmer is unlikely to be willing to give up that much space from their farmer operation. I do know farmers who have their own private runways, but they love flying and so are willing to give up some income to have a runway. They are giving up thousands of dollars in gross income to have that runway.
I happen to have a backyard that is big enough for a helicopter (I think - I never measured but I think I'm at the minimums the FAA requires), but I have an oversized yard. There are a lot more places for a helicopter. Most local parks have enough space, but I think communities would object to regular use. (if used only a couple times a month no problem, but more that and the noise and need to clear everyone else out will make it an objection)
This plane isn’t a 737, it isn’t even a jet, it doesn’t run the motors the same way, the flight profiles are all different.
400 Wh/kg are almost there [1].
For cars the economics is a dicey proposition. Because $/wh is important. The extra range (dubious) or lower weight has to cover the cost difference.
But for electric aircraft there is a lot to be gained by weight savings.
I wonder how annoying this is for the engineers to stay within landing weight limits (MLW)
They need to account for it of course, but it seems more like account for it, not difficult. Any engineer in this space able to comment?
Technically, an empty battery weighs less than a charged one.
In practice, the difference is negligible.
Some items to consider from the video
1. short flights spend an large amount of energy simply having the engines running during taxi to/from the runway.
2. Take-off also consumes much more fuel than cruising.
3. 1 & 2 combine to push airlines to prefer larger & larger planes making longer trips when using fuel (it's how they're managing that 45.9 seat mile number - it get much worse for shorter trips).
4. They're already pushing the 400kwh/kg range for batteries (I believe he makes an offhand comment in the video that they're using 8 packs, with roughly the capacity/weight of 4 tesla battery packs - which would put their batteries in the ~4k lb range if we estimate by teslas pack weights. They are likely pushing to go lower than that. I think it's not crazy to consider they're targeting a production weight ~50% below your guess - in the high 3000s)
5. On top of fuel savings, one of his more compelling points is that maintenance on their engines will be much, much lower. Jet engines are expensive to service, maintain, and repair (thousands of parts, complicated designs, extreme operating conditions). Their motors are basically 450kg dc motors - it's a giant drone motor mounted on an airframe.
6. they seem to have quite a bit of interest from existing airlines (ex - united) so apparently this does seem compelling to them.
7. He quotes a $5 take-off cost in electrical power. Something like an Embraer ERJ-135 uses ~20 - 30 gallons of jet fuel for the same thing (~$100). If they target a plane that's doing very frequent takeoffs/landings, operating costs could be considerably lower, not just lower.
---
Personally - I don't know if they'll make it work, but it's definitely an interesting play, with more real thought put into it than most attempts I've seen.
4. Remember my predicted number is on the low side of how much juice they would need. Of course they get much better efficiency than a conventional jet on taxi and takeoff, so maybe it ends up being closer to what you are saying. I wish they had some more hard data.
5. Yep, commented on this in another post but even just removing takeoff wear and tear on a conventional engine would be big.
6. I would take that with a big dose of salt. United has a deal with Boom (a complete fraud of a company in my view) to purchase planes. So maybe not the best metric.
7. I haven't done the math but the $5 takeoff doesn't pass the smell test for me. $5 doesn't buy much juice (50 kWh? So like a gallon of jet fuel?) and getting a 30k+ lb plane to cruising altitude is not trivial.
"Personally - I don't know if they'll make it work, but it's definitely an interesting play, with more real thought put into it than most attempts I've seen."
Totally agree, which I never thought I would say about an aerospace startup.
This plane is designed specifically to cost less to operate. I'm pretty sure they figured it out, which is why they have over 9b in order commitments.
It is a valid question though: how do we get more of the long distant freight onto trains. Followed closely by how to we get existing freight trains to move to all electric instead of diesel electric (I've been told railroads have studied this: if diesel gets to $8/gallon it is cost effective - but I can't find any references to cite and so you should take this "Fact" with some salt)
I'm not sure how building an electric aircraft would help with this. Are people going to suddenly switch to commuting by plane?
Fixing America's commute problem is primarily an urban planning one (ie, putting all the homes nowhere near anything) and not an insufficient-electric-aircraft one.
Likewise, if you're a nerd, you can spend your free time building stuff you thought you would never get around to.
Yes, AI as marketed is a bit of a snakeoil, but much more real and meaningful than crypto and social media. And math nerds finally can get a high paying job that's not about peddling ads or figuring out how to make a hedge fund even richer.
tl;dr I have a few qualms with this app[1].
Now, this thing might take off (pun intended) anyway, for one simple reason: a theoretically faster train does not compete with it if it doesn't exist. The midwest and west are chock full of towns whose rail connections were either abandoned or never existed in the first place, but have regional airports. This thing would be perfect to service feeder flights from hub airports to regionals or as a charter plane.
That being said I wouldn't expect this to revolutionize air travel. You're still going to be packed into a sardine can and made to pay extra for the privilege of bringing a reasonable amount of toiletries with you. And all the long-haul flights are still going to be using fossil fuels because the energy density of batteries sucks. But still, I'd rather have this than 10 million AI companies.
[0] 500 miles for hybrid operation on SAF, because the FAA would not certify a plane with such a small range
This is utterly 100% false!
The US made the decision to focus rail roads on freight. You never think about freight because you never use it for anything personal, but it is still there. The US beats any place in Europe for Freight and few countries even come close to US for freight rail.
There was a decision made to get rid of passenger rail. However most of those destroyed routes are routes that nobody sane would put passenger rail on today even in high rail mode share countries. There are only a small number of routes should return - for most of the lost routes a bus is better. That isn't to say passenger rail is bad. However the routes we had were bad.
125 mile range is also far from being suitable for all <2 hr flights. I don't think there are many sub 125 mile connections either.
Love to see this work out. 100 pax and 500 mile (electricity) range minimum is where I see it having a (good!) chance for mainstream.
Now, I think this is very neat, but I doubt we'll ever set foot on an electric plane this century.
Boston, Massachusetts (1h) Washington, D.C. (1h) Philadelphia, Pennsylvania (45m) Baltimore, Maryland (1h) Toronto, Ontario (1h 45m) Montreal, Quebec (1h 30m) Cleveland, Ohio (1h 45m) Pittsburgh, Pennsylvania (1h 15m) Buffalo, New York (1h 10m) Providence, Rhode Island (45m) Portland, Maine (1h 10m) Bermuda (1h 50m) Nantucket, Massachusetts (1h 15m) Martha’s Vineyard, Massachusetts (1h 25m) Ottawa, Ontario (1h 30m) Quebec City, Quebec (1h 45m) Rochester, New York (1h 5m) Syracuse, New York (1h) Manchester, New Hampshire (1h) Bangor, Maine (1h 25m) Burlington, Vermont (1h 10m) Richmond, Virginia (1h 10m) Norfolk, Virginia (1h 15m) Raleigh/Durham, North Carolina (1h 25m) Charlotte, North Carolina (1h 45m) Greensboro, North Carolina (1h 30m) Charleston, South Carolina (2h) Myrtle Beach, South Carolina (1h 45m) Savannah, Georgia (2h)
If it gets a little better than current 2 hour flight time then Detroit Chicago and Atlanta are in range - very significant.
The range is apparently 125 miles electric, and 500 miles as a hybrid. That's not enough for Melbourne Sydney. Give it a couple doubling-times though (5 years total?) and it will be.
Meanwhile aircraft take forever to develop and there should be enough of a market in shorter hall flights to occupy a scaling company in the meantime anyways.
High altitude where the air is less dense is better for speed due to less drag. This is also power source agnostic.
Fuel is often placed in wings because adding/burning fuel from your center of lift means your CG doesn't significantly change through a flight and you spend less on pumping fuel within the aircraft. With batteries, you are looking at a constant mass from the beginning of the flight to the end... so you can place it anywhere. Electric motors are orders of magnitude lighter than jet engines. Also, you don't need to pump electrons against gravity so placing all of that weight lower has handling/performance advantages.
By using an airframe shape that is well known, they are reducing risk and appealing to existing pilots. By building it from the ground-up, they are taking advantage of differences between the tech.
eg: all of that weight in the fuselage instead of the wings means that rolling is going to be much more nimble. Yaw might be affected as well, depending on the placement/moment of the batteries.
I know many planes use their wings as fuel tanks but given the weight of batteries maybe that doesn’t work.
I agree it’s interesting. Not a small undertaking.
Which may result in them being too cold and you needing to spend power heating them, so someone needs to do the math on that.
If you build only the propulsion system you would be 100% dependent of existing aircraft companies, which are heavily invested in jet engines. It would probably be much harder to innovate and make good design choices in such a setting.
Every kg saved is a kg more of freight that can be transported (or a little less fuel used to keep the plane in the air); save 500g for each seat of a 200-seat plane, and you can put one more paying passenger in the cabin.
https://www.weflywright.com/products/motor
But then again, they also ship now stuff for datacenters (facepalm):
It would be like Toyota marketing the Prius as an electric vehicle, then buried in their presentation sneaking in the gas propulsion. Same with Chrysler Pacifica (32 mile electric range).
Generation II then.
>Aircraft have two main types of weight limits: the maximum takeoff weight is composed of dry operating weight (DOW) plus payload (passengers and cargo), collectively the zero fuel weight (ZFW), plus the trip fuel, contingency, alternate, final reserve and the block fuel (taxi fuel), and the maximum structural landing weight, with the maximum structural landing weight almost always being the lower of the two. This allows an aircraft on a normal, routine flight to take off at a higher weight, consume fuel en route, and arrive at a lower weight. [0]
More likely, this replaces the turboprop or commuter jet from Colorado Springs to Denver to catch the connecting fright to any other major airport.
A piston or turbine powered aircraft can run all day.
Odd added benefit: the potential ability to jettison a huge part of the weight in extreme emergencies to increase flying time by the backup ICE system.
Or is the noise from turbulence through the air or something? I honestly would think they'd be minimising turbulence anyway for energy efficiency.
I happened to be in Plattsburgh the day of this flight, on my way to a fishing trip on the lake. They used that facility for the long former SAC base runway, but I think it’s also appropriate given the nature of the NY North country that an ultra low operating cost aircraft would see flight there.
The death of most industry really hurt these regions, which are largely cut off from the prosperity of the normal economy. The ability to affordably link places like Plattsburgh or Watertown NY to the broader world. That region in particular prospered with rail links driven by iron and timber.
90 minute flights to places like NYC metro or Boston Metro would be transformative, and may even create new airline operating models.
The key thing question is whether smaller more frequent flights eat up too much runway time to be economical.
For people commuting from suburb to suburb you put bus connections at the train station. Buses are lower capacity but cheaper to purchase and operate so you can run a bunch of them in low density[0] for improved coverage. If demand is really bad[1] you create a "microtransit zone" - i.e. offer shuttle taxi service to the rider's final destination.
What I'm describing is basically how UTA's FrontRunner commuter rail service works; but it's not materially different from, say, the NY MTA's LIRR or MNR besides the larger scale of the NY systems and the fact that New York is weirdly bad at buses. For various reasons America has actually done decently well at retaining the commuter rail systems that worked and rebuilding the ones that got scrapped. This is primarily because these systems tend to be small-scale enough that state & local governments can fund them with their own money and the meager amount of FTA funds available.
The comment you replied to confused "rail commute" with "commuter rail"; but the grandparent was specifically talking about intercity travel. Here is where America is actually malincompetent[2] at building anything. Our primary intercity rail operator, Amtrak, was built as a last-ditch service preservation measure as railroads were bleeding money on passenger traffic. It doesn't own most of the rail it operates on, and that rail has been actively getting worse as Class I railroads have been destroying their own infrastructure (especially Union Pacific). The two-and-a-half attempts at building high-speed services in the US have all been various flavors of bad:
1. The most successful, the Acela, works primarily because Amtrak owns most of the corridor. Even then, it barely gets up to speed because "high speed[4]" (80+ mph) trains have to be grade-separated in the US, which is expensive, and the Acela was sold on the promise of incremental upgrades that haven't really panned out
2. BrightLine partnered with a freight railroad that wanted to get back into the passenger market, and it's actually operating at "higher speed[4]", but it's also bleeding money. They have a second route planned from Los Angeles to Las Vegas, but it's a project they bought out because it was... also bleeding money.
3. California wanted to build their own Acela, with blackjack and hookers, and wound up massively overselling it to voters. At least in terms of how much it would cost and how quickly it could be built. They bet the farm on FTA funds that got impounded the moment Trump retook office. I have no idea if this will ever happen.
You'll notice I never mentioned population density, and that's because it doesn't matter for intercity travel at all. The vast majority of flyers get a taxi to the airport and a rental car at their destination, and it still works out anyway. The only difference to those kinds of travelers between a train and a plane is time and whether or not they have to take their shoes off before boarding the vehicle.
[0] Or, if you're New York, you run way too many of them through medium and high density areas that really SHOULD have a subway but don't anyway build QueensLink and NO WAY WITH QUEENSWAY
[1] From a customer perspective, anything less frequent than an every 30 minutes bus probably could be served better with on-demand taxis.
[2] Malicious? Incompetent? Why not both!
[3] I am going to use "commuter rail" to refer to both commuter and regional rail systems as they are roughly the same scale. The difference comes down to scheduling patterns: commuter rail is scheduled around 9-to-5 rush hour traffic while regional rail is built to be more broadly useful.
[4] Strictly speaking, "high speed rail" means 125mph or higher and anything less is conventional speed. Rail just was already pretty fast even before Japan decided to make really fast trains.
When you size a gas engine for a plane, you design around the power needed to takeoff on a given runway, which is fine because in cruise, you will throttle down and use less fuel.
When you design an electric vehicle, if you design it the same way, you end up carrying effectively dead battery weight, which also affects power consumption during cruise (you either go faster, or use use more wing, which creates more induced drag).
IF you design it for cruise, you end up being horribly inefficient at takeoff.
The only 2 solutions are
1. 10 mile long runway where you can take your time accelerating, to reduce the torque requirement on the motor. You would basically limit the current draw and the plane would accelerate slowly, and eventually you get to cruise speed
2. Changing your flight profile, where you get to high altitude ASAP where you can be more efficient,
There's already an Australian electric trucking company trailing plug n'replace heavy battery packs (with a forklift).
That allows for fast turnover times while used batteries recharge at terminals.
"My father, a mechanical engineer, was a tireless advocate of the hypocycloid crankshaft mechanism."
For some reason just reading that brought a smile to my face.
1. Freight customers spend longer waiting for their deliveries, and pay more money for them. As a result, a lot of mid-size freight customers have moved to trucking instead, and the market has shrunk.
2. To save money as less-valuable cargo is pruned from their networks, freight railroads have been downgrading their infrastructure from double- to single-track with sidings. This would be acceptable, except...
3. Freight trains have gotten longer and longer in order to reduce the crew needed to attend to a given amount of freight. Sidings on single-track routes are rarely long enough to accommodate mainline freight trains, so passenger rail gets delayed, and grade crossings stay closed for way longer.
That last bit is actually why I personally complain about freight railroads. I am someone who has spent a good chunk of his 2026 lobbying Utah's state representatives to adopt the Rio Grande Plan[0]. You see, Salt Lake City is divided in thirds by UP freight mainlines, which get hourly freight through-traffic that paralyzes car and pedestrian traffic across the various sides of the city. The railroads themselves don't inconvenience passenger train traffic[1], but they absolutely make it miserable to walk, bike, or drive across the city, and we can't run any transit services parallel to the railroad for obvious reasons. Everything that has to cross the tracks reliably has to go over one of two rail-crossing bridges in the entirety of downtown.
The reason why you are saying "a bus would be better" is primarily a matter of federal infrastructure spending. Buses get to ride on the Interstate Highway System for cheap, and government-provided highway infrastructure is significantly better for both freight and passenger traffic than the privately run railroads can offer. But at the same time, buses are a demonstrably worse answer to the question of "how do we get a bunch of people from one city to another" than trains or planes.
Personally, if money was no object, I'd call for the government to run intercity rail corridors along highway rights of way with open interconnection, overhead catenary, passing tracks, and passenger-priority dispatching. These would specifically be open to both passenger and freight rail, specifically because both are suffering under the weight of hedge funds that moonlight as Class I freight railways.
[0] The Rio Grande Plan is a citizen-led initiative that calls for building a train box in downtown Salt Lake City along 500 West and burying all heavy rail freight and passenger traffic inside of it.
[1] ...because we built our own railroad parallel to the UP mainline. Amtrak's California Zephyr service is absolutely inconvenienced by Union Pacific, though - in fact, it's the worst delayed route in the entire network!
A bus is better because you still need roads for last mile freight, trades and other things that can't run on transit. May as well also run a bus when those roads are not congested anyway.
The only way to reduce current is to put batteries in parallel, which for a given voltage doubles the weight of the battery pack.
You could go with lower voltage, but that means for a given, power, you need more current, which drops your efficiency.
This is supposed to be able to handle "up to" 2-hour flights, and (for jets at least) takeoff power is about 3x cruise power, so about 1.5 watts per watt-hour of battery, or a 1.5C peak discharge rate. What chemistries are you thinking of that cannot handle this?
https://www.heartaerospace.com/newsroom/heart-aerospace-comp...
I still think it is an amazing achievement. I just don’t see how they were able to get it done on $5 worth of power, or they just quoted the wrong price.
Again, I believe that the napkin math checks out.
So you can barely make it work if you price electricity at a rate that doesn’t exist in the country they did it, using an amount of power that much, much smaller planes usually require to stay aloft (A Cesnna 172, which will struggle with 4 adults, uses 145hp/115kw for takeoff and climbout at a much lower speed). A plane of comparable size and capacity uses 1500-2000 hp turbine engines. That lines up with their own megawatt plus claim.
Regular rates in the area they operate in get them less than 25kwh. They would have had to negotiated a hell if a discount to have pulled it off. And even so, it would be a deceptive claim. It’s like claiming that you doubled the cost efficiency of a 737 (by getting a sponsorship from Shell).
Drag coefficient is about the shape and needs to be multiplied by area to get drag. Your car is a lot smaller when viewed from the front than a 737.
And there's no way a plane flying at the speed it does has the same drag losses as two EVs.
But you found out... how?
They must be good at something, otherwise China wouldn't be where it is.
So flat out dismissing anything from China is not enough of an argument.
Mind you, I'm not saying you're generally wrong, just your "generally" is wrong. ;-)
It makes more of both as the Chinese grid gets cleaner.
And in larger aircraft, multiple independent engines. See for instance ETOPS
https://en.wikipedia.org/wiki/ETOPS
From the pictures, I see that this new aircraft has 4 engines. So it should be adequately resilient to single engine failure.
It's why I believe hybrid cars that use a gas motor only to charge the batteries are more reliable and more efficient.
It's surprising what you can fly formation with, even without an engine [1] :-)
https://www.youtube.com/watch?v=G0icOICQLTc
Dumping (most of the) water before landing:
https://www.youtube.com/watch?v=I4Yv-V7eozk
[1] this particular glider does have a small engine for takeoff, but maximum speed with the engine extended is 180 km/h and here they are flying at 280 km/h.
That glider next to the world's fastest aircraft (in 1953) dressed up for a fight, how about that.
And they can water the grass...
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So several thousand $ to get trained and certified and finally be ready to get towed and soar...
but just a few hundred (California) to try for half an hour behind a pro in the cockpit--oh yeah!
...omg they let you fly the thing for another couple bucks!!!
Here's a video of me taking a student for their first lesson:
https://www.youtube.com/watch?v=RDZN21xzsRo
That's in a DG1000, actually this exact one ZK-GGR:
https://www.youtube.com/watch?v=PeueijUoL70
https://www.youtube.com/watch?v=r0ShTUTiqlM
And how that looks from the other end of the rope:
https://www.youtube.com/watch?v=sRxcJR-zipI
And from the door of the hangar (using the runway in the opposite direction). Turn it up!
https://www.youtube.com/watch?v=RUnXuMVhKfs
Coming back to more like the current topic, an electric powered glider:
https://www.youtube.com/watch?v=7F2gS9ENl5k
Also from Stefan's channel, some fun here in New Zealand ... this flight passes just a couple of km from the Lord of the Rings "Weathertop" site (Google maps knows it).
Their off peak prices have generally been overnight, ideal for truck charging, though they have started having them around noon too like many other nations with growing solar share. Great for a mid shift top-up.
Coal is worse to burn than gasoline, but a car engine throws 80 percent of that away so you have to burn more compared with an efficient EV.
This has all been debated to death for over a decade, MIT has interactive tools to calculate figures, there's really no excuse for not knowing this about a subject you are so passionate about.
The full power system for a prop looks like this: you have a battery of a specific voltage, which then runs a motor, which then runs a gearbox, which then turns a prop.
The motor and the gearbox can be considered as one unit - an electric motor has two factors, KV(RPM/volt) and KT(torque/amp). The higher the KV, the lower the KT. A high KV motor spins fast, but draws a lot of current for the same torque - putting it through a reduction gearbox turns it into a low KV, high KT motor. Naturally, low KV motors or (low KV setups) are more efficient because they draw less current for a given torque, and the heating power loss varies with current^2.
The prop needs to spin at certain RPM for max aerodynamic efficiency. Given the slider for motor/gearbox selection between high KV/low KT and the opposites, you generally want to have as high voltage as possible, so that you can run a low KV/high KT setup, which means that for the given torque, the current is minimal. I.e you have a motor spinning really fast, through a large reduction gear, driving a prop at the necessary speed and torque without much load on the motor.
So lets say you determine that you want a certain voltage, which requires a stack of cells in series. The only way to get more capacity is to duplicate that stack and put them in parallel. So your weight becomes quantized by the number of stacks you have in parallel. And the more stacks you have in series, the higher the weight jumps between parallel stacks counts.
Subtracting cells from stacks doesn't work well. Lets say you have a single stack of 10 cells 10s1p. If you do something like 8s1p, you lower the output voltage, which means you need to have slightly higher gear ratio to spin the prop at the same efficient rpm, which means you draw more current, which means the extra capacity in the cells doesn't really matter if you are drawing more current.
If your motors draw W Watts at peak, and you have N cells at V volts then the peak per-cell current will be (approximately -- there are internal losses) W/(NV) regardless of the geometry of your stacks.
If N is small, your designs may be restricted, but I'll hazard a guess that N will be large for a 30 passenger plane capable of 2 hour flights (e.g. a Tesla model 3 is almost 3000 cells; 31s96p).
The overall point that Im trying to make is that slight battery specific energy density improvements don't matter when compared against the power losses which are proportional to square root of the current.
I don’t know what speeds they flew, but AFAIK most maiden flights are very tame. My point stands, low hundreds of kilowatthours of energy seems like the right ballpark.
Have you ever seen a car and a plane? The Tesla model x has a frontal area of 2.6 sqm and a 737 fuselage alone, without any wings is already 11 sqm. With all attachments it’s at least 20 sqm.
And half of the energy for altitude gain and half for drag is way too optimistic.
The flight cost more than $5 in energy.
Yet you state their frequency as some sort of statistical fact. Your anecdotal experience doesn't make it any more or less true.
Which means nothing. You still dont get my point.
> Also this is just a conversation, not an academic debate
It can be both.
100kwh was an extremely generous amount of energy to allow for $5. Actual, real world, best case scenario industrial pricing in the region they are in would give them 50kwh for $5.
Look at your numbers again with the fantasy pricing. You are saying that they took off with a normal amount of power for a plane that size, then cruised around using an amount of power (45kw) that wouldn’t keep a two person plane 1/20th the weight airborne. Now cut that budget in half.
Even the most efficient planes on earth - single person powered gliders - need about 15-25kw to maintain level flight at much lower speeds. Keep in mind that drag increases with the square of speed, and this plane is traveling significantly faster than any of the low power planes I’m citing. Citing drag from a Tesla is kind of irrelevant because the whole way an airplane works is by creating lift via drag. The Tesla has wheels to hold the weight, so incurs a much lower penalty for weight.
The reason I’m so skeptical is that I have done the engineering calculations to convert my own very small (sub 1k pound gross) plane. It would need about 30kw/h to maintain level flight with just 1 person in it.
Again, I am incredibly impressed with the engineering and what they have accomplished. I just think that one of their marketing figures was pulled out of someone’s ass.
No, I’m not saying anything about 45 kW, you’re, again mistaking kW for kWh.
> Citing drag from a Tesla is kind of irrelevant because the whole way an airplane works is by creating lift via drag.
That’s already included in the drag coefficient that I quoted, and I know what induced drag is. Airliners are incredibly slippery because of their shape, a Skyhawk (or any other small GA plane) is a brick compared to that.
I’m not arguing about the $5 figure, it might as well be $20, I don’t know where they buy their electricity, but it’s still a very low number compared to anything burning Jet-A or avgas, and it’s absolutely a “low hundreds of kilowatt hours” number.
There's a ton of small routes that just aren't getting much service now because of operating costs - the founder speaks to that in the video - that this could serve.
A slightly larger aircraft able to do ~300 miles on battery and then say 1,000 in hybrid mode, might resurrect the economically unviable but relatively fast LHR/LGW flights down to NQY. The six hour drive is pretty, but... yeah...
Now, of course, most of the hassle of getting to NYC from Boston is transit to and from the airport. And of course, transit from JFK, Laguardia, etc into the city.
There are at least 5 capable airports/airstrips closer to me than Logan or T.F. Green. Only one of them, Worcester, offers NYC flights. Worcester is almost an hour from me on average, and a bit more expensive. It’s an hour from takeoff to landing (I’ve arrived 10 minutes before takeoff, at the PARKING LOT many times without it being an issue).
If they can get this in and out of even smaller airports, like in Stow, MA, which is beyond capable, it will be a gamechanger.
I don’t know where you live or what you drive, but I just punched in a destination 200 km away as the crow flies, the Alps are in the way and I’m looking at five hours of driving.
Also, water.
But I doubt we have the capital to buy them new.
Assuming you have a straight road in that direction with a speed limit that allows an average speed of more than 100km/h.
There are a lot of "island hopper" and bushpilot mini airlines in the world. The current world record is a route in Scotland that, on good days, takes less than a minute of flight time [1].
It is much much easier to supply such islands with electricity (there almost always is a power grid tied to whatever the nearest mainland is) than to continuously haul fuel around.
And in Croatia... that is easy enough distance to cover Rijeka-Zadar for example, which is about three hours worth of car or bus drive.
[1] https://en.wikipedia.org/wiki/Westray_to_Papa_Westray_flight
Even then there are lots of flights in Europe that are between cities less than 1 hour apart.
This idea generally makes more sense in Europe than the US, I think.
[1] https://en.wikipedia.org/wiki/Short-haul_flight_ban?#Overvie...
Report recently from my area.
https://www2.gov.bc.ca/gov/content/transportation/transporta...
Of course those -should- be easy on trains too…
Because the required buffer is HUGE and we’re at a point where electric planes barely have enough energy for the actual route. So they’re doing the sensible thing here, flying the actual route electrically and falling back to combustion if the plane needs to divert.
Yup. And to bring this point home:
"Only" doubling the battery capacity likely eats well over half of the payload capacity, in terms of mass. So your 38 seat plane is now a 19 seat (or fewer) plane.
You make it sound like it is acceptable for a badly planned flight to have a fuel emergency. It is not.
If there is a fuel emergency (or the plane lands with less than 30min of fuel) there will be an incident investigation that treats the situation as serious as if the plane had crashed. If the investigation discovers it was nothing more than bad planning, (at minimum) the planning procedures will be changed to ensure it never happens again.
No the investigation isn’t as serious as if the plane had crashed. In July 2026 nine planes simultaneously had a fuel emergency in London. You bet it’s different from nine planes simultaneously crashing in London.
It helps to understand different kinds of fuel emergency. Declaring a fuel emergency to get to a diversion airport is very very different from having 30 minutes of fuel left.
That aircraft would need a very large battery to do that, and it's way more efficient to have some burnable fuel there that you'll never actually use.
I somewhat doubt that. Part of the advantage of the design is that the generators don't need to be sized as big enough to power take off, climb and a potential go-around on landing. They only need to be sized as big enough for cruising.
So powering them up during critical phases wouldn't help with safety. If anything, normal operating procedures might actually require shutting them down during critical phases.
What this does mean is that the batteries need to be reasonably full when it comes into land, possibly as high as 50%. And most go arounds will require immediately powering up the generators, so it probably needs to be fuelled for all but the shortest flights.
I would guess the opposite. Many parts in a turbine engine are "lifetime limited" by number of engine starts. That is, you are required to tear down the engine and replace certain parts after a certain number of engine cycles.
That makes the economics of the turbine hybrid radically different if you need to start it every time you land vs. only the rare cases where you need to dip into fuel reserves.
For example, the PT6A (a common 500-1000hp turboprop) requires the turbine and compressor disks to be replaced every 16,000 cycles. That's about 5 years of commercial service at 4x round trips per day. But if you only start the engine once in every 10 flights, now those components (theoretically) last for 50 years of flying.
There aren't that many existing flight routes that will fit into the 125 mile range (though the existence of this plane might change that), so I suspect we will see most of these planes go into service on slightly longer routes. So they will probably still need one cycle per flight.
Though... The video isn't quite clear if the 125 miles is what they can fly without starting the turbines or if it's what they can fly without needing the turbines ready to act as an emergency reserve. I actually suspect it's the later and this aircraft can make it to 200+ miles without starting the turbines.
Where I live, there aren't that many 125 mile flights, but there are a lot of 200 mile fights.
I also suspect the turbines are sized so that only need to start one of the two turbines on most flights, which would extend lifetime a lot. Ideally the turbines would be sized so that one is enough for cruising, and with two you can actually charge the batteries after a go-around (enough to enable a second and third go-around)
But still very serious. 9 simultaneous fuel emergencies could have easily overwhelmed ATC and snowballed to worse issues.
Something lead 10 different aircraft to make the exact same mistake and find themselves without enough fuel for a safe diversion. There will be recommendations to try and prevent it from happening again.
So you are now in agreement that $5/100kwh is unrealistic? That was my whole point the entire time.
We pay about $120 for the privilege, which takes 20 minutes of flying.
So I think even in this case the reserve capacity is "needed" (for the reserve requierement), but I can see them realistically being able to fly between the islands purely on electric power.
Unless we ignore the additional maintenance cost of having to completely different proportion systems to maintain (and it is worse than a twin engine plane, because the propulsion systems are different, so you have to stock up on more different kinds of parts and possibly have different kinds of mechanics on staff to understand them)
Having the turbine, electric motor, gearbox, and potentially clutches to isolate the turbine or electric motor from the transmission seems pretty viable though. This would waste a little bit of power keeping the turbine spinning (unless there are clutches) but would also ensure that the turbine’s been spun recently, the oil pumps are primed and the bearings are lubed and ready to go.
Not that I’m saying a turboprop turbine like a PT6A is a simple device, but compared to a high-bypass turbofan like you’d see on a 737 or A320, they are considerably simpler.
Edit: looking quick, the time-before-overhaul (TBO) on modern PT6As can be up to 6000 hours, with a ~2000hr Hot Section Inspection. I’m not sure how “spinning but not burning fuel” counts on TBO, but it should at least mean the HSI is simple.
But... given that turbine APUs already exist for ground power and are already engineered to be as light as practical, my naive guess would be that it's easier, simpler and faster to just use a COTS APU as a series hybrid rather than trying directly couple a turbine to the propeller.
On inspections and overhauls: I'd expect that not needing to start the turbine at all on a given flight massively helps the economics of the airplane. Turbines often have parts that must be replaced after a given number of (startup) cycles, and that's going to be especially important for a turbine that is only expected to run for a short time (if at all) at the end of a flight.
If you only start the turbine on, say, 5% of flights, that means you get 20x as many flights before overhaul/inspection. I could see that being incredibly attractive to airlines.
For private, yes. For airlines, the requirement boils down to basically enough fuel to "fly to the intended destination as scheduled, then loiter for XX minutes, then fly at normal speeds to a pre-designated alternate, land".
For short flights, that means the fuel loaded at departure can be more than twice what is actually needed to get from A to B...
Which is why the hybrid approach is fairly clever: You can use it for ~125 mile flights, and remain 100% electric on ~95% of flights. Whereas, without the reserve turbine the practical limit would be ~60 miles. On the ~5% of flights requiring more range, you're still mostly operating on electricity.
> You can use it for ~125 mile flights, and remain 100% electric on ~95% of flights.
To your question… Feasible: no; Possible: yes.
The pilots took exactly enough fuel to reach their destination. They didn't have enough fuel to divert to an alternative airport. They didn't even have the mandatory 30min of reserve fuel. They did not account for a minor holding pattern just before landing (ironically, because another plane had a fuel leak).
The crew failed to declare a fuel emergency, and crashed 18km from the airport. They had only been in the hold for 10 min when their engines ran out.. they were very short of fuel, the pilots knew they were short. They should have diverted (or declared a fuel emergency) almost an hour earlier, but they didn't want anyone to know how close they were cutting it.
If I look at a BYD at my local dealership, and compare it to a comparable spec German car (I live in the UK, so tariffs are not the thing shifting the needle here), I can see where the cost savings are and the trade-offs.
I don't think they're artificially more affordable. I just think they're more affordable.
Using public funds to invest in capital expenditure is - outside of the US - considered a wise use of public funds. If the result is a more competitive industry, whether that's ship building (South Korea), steel production (recent UK nationalisation efforts), military hardware (United States), or medical research, physics, chemistry, computing (look at the history of all the G7 there), and so on, and so on... irrelevant.
China has decided to spend it on complex manufacturing that they've been the supply chain for to Western manufacturers for the last 30 years. That's not controversial - it's been obvious this is where they were heading for some time.
I'm not being super academic with citations, but the CCP investments in BYD, to the point it makes no sense to exist without aren't exactly hard to find secrets.
You're not comparing comparable things, in the UK, there is a great deal of expectations of what an employee has as rights for instance. There are extremely rigorous safety regulations that are very onerous. We can debate wether those are justified but it's a very complex topic you're brushing off. Their innovation seems mostly on small iterative gadgets, but look more closely into what they tolerate as self driving and the death it causes, and be sure you want that in the UK for profit margins.
I'm really not against neither subsidies nor artificially inflating one's strategic advantage at all to develop a market and corner the competition. I never said China is wrong to do what it's doing. What I am saying is that its dangerous for us outside of China to buy into it now. Beyond the security implications of chinese robots with sensors everywhere roaming about cities the CCP considers their ennemies, there's just the dependency risk, there's the "how much do you trust the people who fed paint to their babies to handle super dense explosives that cant be put out by water in dense cities", and the basic question, maybe its better to have the lightest car possible, not the most gadgetty with drones and ipads.
So the basic point above "China has more electric trucks therefore it makes economic sense" is helped by none of this
If you steal my IP and you make a better - or at least comparative but cheaper - product, that's on me for not innovating further.
Chinese EV trucks make no economic sense even though they're 30% of China's fleet but also they're only investing all that as a trojan horse even though they use them almost exclusively domestically, plus the old "Asians don't innovate they just copy" canard even though there wasn't much Western IP on electric trucks to copy in the first place and China's battery technology is somehow not Alibaba knockoffs but more performant than Western equivalents (whilst state sponsored Chinese industries remain generations behind in stuff that's actually strategically critical for them to clone via industrial espionage like semiconductors and jet engines)
If you replace 'public' with 'VC', isn't that the exact same as the US does in Silicon Valley?