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."
Hybrid after the first 125 miles, total range 500 miles. Their problem is diversions - an incident at the destination airport may mean an passenger aircraft may need to land at an airport which could be a couple hundred miles away. The hybrid powerplant throws the fuel efficiency numbers off so goal is not to run it unless needed, but they could not get certification without it.
Honestly, I'd feel better knowing it has a reserve system in case there's any issues, even if the batteries have more than enough power, beats having it and never using it, than needing it and suffering as a result.
So what do regular aircraft do when they run out of fuel? They require a forced landing. Aircraft fly with a buffer of fuel though to avoid such situations, so why can't an electric aircraft fly with a similar buffer on it's range? ie. Always fly less than the current charged range of the aircraft.
> Aircraft fly with a buffer of fuel though to avoid such situations, so why can't an electric aircraft fly with a similar buffer on it's range?
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.
Regular aircraft are required to have enough fuel to be able to divert to the alternate airfield in their flight plan plus all the margins for taxiing and waiting for a landing clearance. If a plane is low on fuel they can declare an emergency and get priority over other traffic, but that obviously is disruptive and should not happen on well planned flights unless something pretty significant happens after takeoff.
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.
Lots of down votes on this but it is a legitimate question. The goal is likely to have the majority of flight off of batteries. That being said, the total weight of the emergency fuel plus generators is likely far less than the weight of the extra batteries they would haul around for the safety margin they need. So they end up lighter and more capable AND don't need to burn fuel. That being said, I wouldn't be surprised if they didn't start the generators during critical phases so they may end up using some fuel for a flight, but not much. Total guess on that though.
> That being said, I wouldn't be surprised if they didn't start the generators during critical phases
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.
Unless they have a whole new airport and flying experience, I don’t think a lot of people are going to fly just 125 miles. That’s less than two hours of driving. It would be 2 hours of just airport shenanigans much less the flight itself.
> 125 miles … That’s less than two hours of driving.
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.
There are a fair number of connecting flights that this is a good fit for. For example, I fly out of Madison, WI regularly and almost always connect through Chicago, which I believe is right around the 125 mile mark.
With limited information form their web site, both. Being able to run pure electric while switching to fossil fuel. [0]
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.
This! Anything unproven makes the flight certification process longer. They already have to get their electric side certified, might as well make the backup generator as easily certified as possible.
My father, a mechanical engineer, was a tireless advocate of the hypocycloid crankshaft mechanism. In the 90s, hybrid vehicles with a hypocycloid-based generator feeding the batteries that make the electric motors go was the application he was going for, especially since hypocycloids function best at constant RPM.
Doing some math. Regional jets get somewhere around 45.9 seat miles per gallon (1). So 30 seats, going 125 miles would take around 80 gallons of jet fuel. This is likely low because all the jets listed are bigger and likely flying longer flights that are more efficient but just go with it.
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.
If they can get the range to within what, for example, an Alaska Airlines/Horizon Q400 flies from Seattle for regional flights (with reserve for diversion airport), that may be sufficient for some purposes.
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.
I'm surprised by the struts supporting the wing; that saves weight (probably important here), but at the cost of drag. Wikipedia suggests a rule of thumb of 200mph being the break-even point for struts vs cantilever, and I would guess this plane is supposed to cruise faster than that. However, I didn't see the cruise speed listed anywhere; does someone know what they are targeting?
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).
That sounds like the breakeven if you're holding wing geometry constant and want to compare cantilever weight cost to bracing drag cost. The real advantage is in allowing for thinner and higher aspect ratio wings like in the Boeing X-66 which was designed to fly considerably faster than 200mph and make fuel savings.
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.
These kind of startup excite me. More so than the "next killer app" or "look what we shoved AI into."
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.
> Cheap electric transportation can finally offset USA's lacking rail commutes
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.
I think you could make a case for that, especially when landing in water. Quite a few dense urban areas people might need to get to have water nearby suitable for landing seaplanes. I think you would end up creating communities further from the urban areas dedicated to this mode of transport. It’s definitely not a simple or guaranteed idea, but it is actually feasible politically and technically.
Not enough population density with single family homes. And if given a choice between living in a condo + better urban planning versus suburban housing, well. And then there is NY.
You can fix the density problem, at least on one end, with park-and-ride lots; every successful commuter / regional[3] rail service puts parking next to the suburban train stations. You just need a dense corridor for people to go to.
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.
Could you imagine the (rather justified?) NIMBYism for all the airports required for commuter flight? If rail can’t be done, flight definitely won’t fly.
Yeah… Fair point! I’ve always perceived NIMBY as “we want the benefits but we want someone else to deal with the geographic price.” I bet we could find people who legitimately want commuter airports but just not near their house… wait… how would that even work?!
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.
It's clearly marketed for remote communities with little to no connecting infrastructure. Think Alaskan wilderness or Hawaiian island hopping. This isn't for getting from LA to Denver for skiing.
Btw, I kind of changed my opinion on AI. Finally, everybody can build an app, so we no longer have to pretend the people who built one and made it big are some sort tech pioneers pushing humanity forward.
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.
USA's lacking rail commutes come down to the fact that America's leaders made the deliberate decision to destroy its own rail network and force people onto planes. The electric range of this aircraft is 125 miles[0], which is at the low end of the range where conventional intercity rail is time-competitive with the plane. A bullet train would absolutely smoke this.
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
I'm rooting for electric planes not because I prefer them over rail but bc I share your disappointment and pessimism about American railway. I much rather take a train but when Amtrak NYC<->DC costs as more than a plane, leaves from the same destination, and takes hours longer then flying becomes preferable. There are many route similar to this. Only legup that Amtrak has is frequency. If planes become cheaper hopefully airlines will afford more of them and offer more frequent flights. I dream of a constant stream of aircraft flying between destinations. But never underestimate greed, airlines will probably reap the cut costs and charge customer the same as before :/
I'm not sure the Midwest is the intended target, here. I think it's more suited to small, frequent trips like island hopping or trips to remote settlements.
Maybe I missed it but they didn't delve much into the TAM.
"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.
Batteries are rapidly improving (on many metrics, but the relevant one here is increasing in energy density).
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.
Canberra - Sydney is one of the busiest routes in Australia with Dash 8 and ATR turboprops on high rotation every day. I could see a small electric aircraft working pretty well there, modulo charging times.
Batteries aren't rapidly improving. Every single battery that has proposed higher energy density also has downsides in max discharge current. We may get at best like 10% improvement over what it is today.
Electric planes can in theory get longer flights, provided they change the flight profile - you spend a lot of energy going up to higher altitude, and the essentially glide down.
The energy used to achieve altitude is then saved in the descent stage. So that’s not an issue for aircraft, regardless of how they’re powered. This is why every flight you’ve ever been on climbs to cruise altitude as fast as possible.
High altitude where the air is less dense is better for speed due to less drag. This is also power source agnostic.
Interesting decision to build the whole aircraft instead of the propulsion system only. I wonder what the decision process was between retrofit of existing turboprop frame vs. build from the ground up? I would expect the level of effort and certification to be much higher building from scratch even though you get complete control.
Aircraft design is very intricate. Change the CG, break the whole system.
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.
It may be too hard to do a good retrofit. If you basically have to tear the entire plane apart and rebuild and recertify it to put batteries in the right places, maybe the costs aren’t worth it for potential customers.
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.
Generally all the weight of the fusaage has to go through the wings anyway so it is structurally more efficient to put weight on the wings in the first place.
In sailplanes we add up to around 200 litres of water to wing tanks in single-seat gliders (empty weight typically around 280kg) to improve the high speed performance (typically up to 270 km/h these days) and ability to fly comfortably in turbulence.
It's surprising what you can fly formation with, even without an engine [1] :-)
[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.
I think an interesting aspect is that on normal aircraft fuel tanks have to be near the center of lift to maintain weight and balance as fuel is burned off. When using batteries, this is not really a concern, and I would think might lead to some more interesting designs. To be sure, if there is space in the wing, awesome - the batteries can now also be used as ballast though too if required.
Wings can also be excellent for heat rejection - in-wing batteries have a lot of surface per unit of volume and are constantly exposed to low temperatures.
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.
Judging by the seats, perhaps making it as light as possible. Existing airframes are relatively light but let's be honest, they aren't trying to save 500g here and there when they have massive jet engines to get everything airborne.
I discussed with people working on aircraft components, and my understanding is that weight is a constant obsession for them. Propose a new system to Airbus/Boeing, and the first question they'll ask is "how much does it weight?"
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.
Agreed. But for related reasons, aircraft aren't really designed for either the structural robustness or balance to deal with big heavy batteries, which is what motivated the clean sheet design.
Heart Aerospace (YC W19) just flew the largest electric airplane ever flown — a 100-foot wingspan, a takeoff weight of 25,000 pounds, and $5 of electricity to get it off the ground.
Nit: When they did the actual flight I did the math on the $5 worth of power claim, and it just doesn’t pencil out even at the lowest power rates in North America. Just to illustrate: at $.05 per kWh (which is less than half the price of electricity where they flew), you get 100kwh for $5. 100kw is what it takes to takeoff a 1200 pound Cessna. Probably about 75kw for an efficient cruise in that same plane.
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.
You can't convert between kWh and kW. 100 kWh = 6 MW for one minute... so there is plenty of power if the flight is short enough. They said the plane has 4 Tesla's worth of battery power, let's assume they are 80KWh packs then that's 320kWh that they could use for a short flight. That's a fair amount of juice, they definitely won't be flying long in a 25 ton aircraft without starting up the auxiliary motor but I have no doubt it will be able to get off the ground on $5 worth of electricity.
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.
The specific claim from the company is that the entire 27 min flight was done with $5 worth of power using an all electric power system with a power output exceeding one megawatt.
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.
The takeoff roll is only a minute or so to lift-off, so it's possible. But also somewhat meaningless, as an airplane can take off for free in high-enough headwinds.
The interesting part to me is that a lot of current electric aircraft development seems to be waiting for battery technology to catch up. They're far ahead in terms of the motors, propeller, electric propulsion control system. The limitation is the battery capacity.
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 first clean sheet airliner to be flown in any category. electric or not, in the US in the last 18 years'
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.
The 737-Max is only not a clean-sheet only because the selling point is pilots don't need to retrain, which is a competitive advantage when selling to airlines.
It beats it by mostly not using the turbines. The turbines are there for long range diversions which should happen rarely enough to not really matter in terms of carbon release.
I was just at Newport Technology preview where they demoed a ground effects aircraft drone. This was a scaled model and the final drone aircraft is designed for 12 passengers. All electric.
It won't likely perform better as it ages but it may continue out-performing a fleet that tends to hold its value. If the maintenance cost of the electric motors and batteries along with the turbines operating at reduced power is better than the maintenance cost of two turbines that are operated at 100% power to take off, it could really pay off, as that tends to be a very expensive part of the operation. Airframes also often appreciate these days, as it is very expensive to buy a new one and an old one is somewhat proven.
This plane basically has to outperform a Saab 340.
Turbine powered helicopters can appreciate in value if demand picks up because the tech doesn't move that quickly, as can GA aircraft that are already old because they're all cheap and rudimentary to start off with. (The supposed appreciating asset tends to cost a lot more than the asset appreciation to maintain though...)
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...
In the video he explains that the goal of the hybrid system is mainly to be used when for some unexpected reason the airplane cannot land at its original destination.
I’ve been tinkering with the idea of a hybrid system where the ICE system is its own bolt on component to an electric aircraft that is used for takeoff and altitude before it detaches and returns to the airfield before the aircraft cruiser on electric power.
Could even have a rocket launch version for cargo
The noise wouldn't be significantly lower during takeoff/landing, only during taxi, right? Good for workers on the tarmac, but doesn't get rid of the largest noise pollution issue.
The moment he talked about "remote pilots managing many planes," I closed the tab. Remote pilots sound great until something goes wrong, and things inevitably go wrong, not often, but they go wrong.
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.
Hybrid! That's what happens when you build new devices around old infra. Steve Jobs didn't design the iPhone around Carriers; it was the other way around.
I still find it crazy that piston engine aircraft still run on leaded fuel. The only reason it is still the case is mostly regulatory. We can make compatible unleaded fuel, we could have done it decades ago, but it would have required costly recertification and maybe minor retrofits and the use of additives, and considering the small scale of GA, considered not worth it.
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.
Wikipedia says “It was initially developed by Bombardier Aviation with the program launched on 13 July 2008 and had two years in-service as the Bombardier CSeries.”
It's true. Good? Nope. This thing will burn giant piles of cash in repairs, and that's not even considering battery replacement, which completely obviates the entire point of this thing.
The interior of the plane is clearly designed by an engineer. They stripped everything down to save weight, passenger comfort be dammed. The seats don't even look comfortable.
They need to hire an actual designer, if the plane weighs 0.5% more but has actual human usability that's worth it.
The company that makes the airplane is not normally the company that installs the interior anyways. The airline that buys the plane typically determines what the interior will look like (stuff like ratio of business to economy, overall # of seats, in flight entertainment, etc)
It being barebones from the factory is not a problem.
But maybe they’re aiming at short haul cargo. And either way, wouldn’t that really be one of the last things to do? Just proving the plane can even get in the air and stay there for a useful distance on electricity is more important than how comfortable it is.
138 comments:
Is this EV or Hybrid?
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...
Hybrid after the first 125 miles, total range 500 miles. Their problem is diversions - an incident at the destination airport may mean an passenger aircraft may need to land at an airport which could be a couple hundred miles away. The hybrid powerplant throws the fuel efficiency numbers off so goal is not to run it unless needed, but they could not get certification without it.
Honestly, I'd feel better knowing it has a reserve system in case there's any issues, even if the batteries have more than enough power, beats having it and never using it, than needing it and suffering as a result.
For anyone looking for the reference, it's stated at 10:16 [0]
[0] https://youtu.be/nM86DBOqgPM?si=BdoZzp1Dxa4S3C_9&t=616
So what do regular aircraft do when they run out of fuel? They require a forced landing. Aircraft fly with a buffer of fuel though to avoid such situations, so why can't an electric aircraft fly with a similar buffer on it's range? ie. Always fly less than the current charged range of the aircraft.
> Aircraft fly with a buffer of fuel though to avoid such situations, so why can't an electric aircraft fly with a similar buffer on it's range?
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.
Regular aircraft are required to have enough fuel to be able to divert to the alternate airfield in their flight plan plus all the margins for taxiing and waiting for a landing clearance. If a plane is low on fuel they can declare an emergency and get priority over other traffic, but that obviously is disruptive and should not happen on well planned flights unless something pretty significant happens after takeoff.
> and should not happen on well planned flights
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.
Lots of down votes on this but it is a legitimate question. The goal is likely to have the majority of flight off of batteries. That being said, the total weight of the emergency fuel plus generators is likely far less than the weight of the extra batteries they would haul around for the safety margin they need. So they end up lighter and more capable AND don't need to burn fuel. That being said, I wouldn't be surprised if they didn't start the generators during critical phases so they may end up using some fuel for a flight, but not much. Total guess on that though.
> That being said, I wouldn't be surprised if they didn't start the generators during critical phases
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.
Regular aircraft fly with enough fuel to change into at least one other airport in an emergency (ideally two).
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.
Simply put, batteries are heavy.
Unless they have a whole new airport and flying experience, I don’t think a lot of people are going to fly just 125 miles. That’s less than two hours of driving. It would be 2 hours of just airport shenanigans much less the flight itself.
> 125 miles … That’s less than two hours of driving.
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.
There are a fair number of connecting flights that this is a good fit for. For example, I fly out of Madison, WI regularly and almost always connect through Chicago, which I believe is right around the 125 mile mark.
The X1, which is what flew, is all electric. The ES-30, their proposed product, is hybrid.
With limited information form their web site, both. Being able to run pure electric while switching to fossil fuel. [0]
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.
[0] https://www.heartaerospace.com/es-30
Surprised they are not using linear opposed piston crankshaftless generators to make an extended range EV aircraft.
Smaller, lighter, simpler, cheaper, and more flexible about fuel.
https://www.youtube.com/watch?v=NeG4zLlFkak
Linear engine starts around 11:19
Turbines are extremely reliable and well-understood in aviation propulsion
This! Anything unproven makes the flight certification process longer. They already have to get their electric side certified, might as well make the backup generator as easily certified as possible.
Good point. Only have one new tech at a time.
Generation II then.
My father, a mechanical engineer, was a tireless advocate of the hypocycloid crankshaft mechanism. In the 90s, hybrid vehicles with a hypocycloid-based generator feeding the batteries that make the electric motors go was the application he was going for, especially since hypocycloids function best at constant RPM.
I say this with all sincerity, I love this sentence:
"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.
From mechanical engineers I’ve met it almost seems a requirement that they have something they tireless advocate for.
Yeah. I bet he was.
It uses aviation fuel only after the electric battery is empty. And uses the fuel to run generators, the motors are all electric.
Its hard to call that the largest electric aircraft IMO. It's electric until it can't, then its not.
Doing some math. Regional jets get somewhere around 45.9 seat miles per gallon (1). So 30 seats, going 125 miles would take around 80 gallons of jet fuel. This is likely low because all the jets listed are bigger and likely flying longer flights that are more efficient but just go with it.
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
This graphic always reminds me why it's so hard to beat gasoline and that batteries kinda suck.
https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...
If they can get the range to within what, for example, an Alaska Airlines/Horizon Q400 flies from Seattle for regional flights (with reserve for diversion airport), that may be sufficient for some purposes.
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.
I'm surprised by the struts supporting the wing; that saves weight (probably important here), but at the cost of drag. Wikipedia suggests a rule of thumb of 200mph being the break-even point for struts vs cantilever, and I would guess this plane is supposed to cruise faster than that. However, I didn't see the cruise speed listed anywhere; does someone know what they are targeting?
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).
That sounds like the breakeven if you're holding wing geometry constant and want to compare cantilever weight cost to bracing drag cost. The real advantage is in allowing for thinner and higher aspect ratio wings like in the Boeing X-66 which was designed to fly considerably faster than 200mph and make fuel savings.
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.
These kind of startup excite me. More so than the "next killer app" or "look what we shoved AI into."
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.
> Cheap electric transportation can finally offset USA's lacking rail commutes
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.
I think you could make a case for that, especially when landing in water. Quite a few dense urban areas people might need to get to have water nearby suitable for landing seaplanes. I think you would end up creating communities further from the urban areas dedicated to this mode of transport. It’s definitely not a simple or guaranteed idea, but it is actually feasible politically and technically.
Not enough population density with single family homes. And if given a choice between living in a condo + better urban planning versus suburban housing, well. And then there is NY.
You can fix the density problem, at least on one end, with park-and-ride lots; every successful commuter / regional[3] rail service puts parking next to the suburban train stations. You just need a dense corridor for people to go to.
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.
Could you imagine the (rather justified?) NIMBYism for all the airports required for commuter flight? If rail can’t be done, flight definitely won’t fly.
Curious, would electric flight be significantly quieter such that airport noise is significantly less of an issue?
Or is the noise from turbulence through the air or something? I honestly would think they'd be minimising turbulence anyway for energy efficiency.
Most of it is due to turbulence. But that doesn't mean that a different engine can't make the plane have a completely different noise profile.
Rejecting stupid ideas that are a net bad for the community isn’t NIMBYism
Yeah… Fair point! I’ve always perceived NIMBY as “we want the benefits but we want someone else to deal with the geographic price.” I bet we could find people who legitimately want commuter airports but just not near their house… wait… how would that even work?!
Stupid in those that lack imagination.
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.
It's clearly marketed for remote communities with little to no connecting infrastructure. Think Alaskan wilderness or Hawaiian island hopping. This isn't for getting from LA to Denver for skiing.
An aircraft like this can be used two or three times a day, while spending the rest of the time charging.
A piston or turbine powered aircraft can run all day.
But it may be for getting from Denver to Breckenridge or Winter Park. A flight to bypass Berthoud Pass in the winter seems quite attractive.
More likely, this replaces the turboprop or commuter jet from Colorado Springs to Denver to catch the connecting fright to any other major airport.
Btw, I kind of changed my opinion on AI. Finally, everybody can build an app, so we no longer have to pretend the people who built one and made it big are some sort tech pioneers pushing humanity forward.
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.
Good for you.
Rare soulful HN comment
USA's lacking rail commutes come down to the fact that America's leaders made the deliberate decision to destroy its own rail network and force people onto planes. The electric range of this aircraft is 125 miles[0], which is at the low end of the range where conventional intercity rail is time-competitive with the plane. A bullet train would absolutely smoke this.
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
[1] https://news.ycombinator.com/item?id=9224
I'm rooting for electric planes not because I prefer them over rail but bc I share your disappointment and pessimism about American railway. I much rather take a train but when Amtrak NYC<->DC costs as more than a plane, leaves from the same destination, and takes hours longer then flying becomes preferable. There are many route similar to this. Only legup that Amtrak has is frequency. If planes become cheaper hopefully airlines will afford more of them and offer more frequent flights. I dream of a constant stream of aircraft flying between destinations. But never underestimate greed, airlines will probably reap the cut costs and charge customer the same as before :/
I'm not sure the Midwest is the intended target, here. I think it's more suited to small, frequent trips like island hopping or trips to remote settlements.
It seems like a great option to get between MSN, MKE, or RFD and ORD. Maybe even an interesting connector between MDW and ORD.
The key thing question is whether smaller more frequent flights eat up too much runway time to be economical.
Maybe I missed it but they didn't delve much into the TAM.
"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...
I didn't get that far in the video but from where I live (NYC) two hours gets you to a lot of very common travel destinations:
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.
Batteries are rapidly improving (on many metrics, but the relevant one here is increasing in energy density).
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.
Canberra - Sydney is one of the busiest routes in Australia with Dash 8 and ATR turboprops on high rotation every day. I could see a small electric aircraft working pretty well there, modulo charging times.
> modulo charging times.
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.
Batteries aren't rapidly improving. Every single battery that has proposed higher energy density also has downsides in max discharge current. We may get at best like 10% improvement over what it is today.
That's max discharge current per cell though. You are going to have a lot of cells in a plane like this.
It’s taken thirty years for lithium batteries to double in energy density, and the rate of increase has tapered off recently.
Electric planes can in theory get longer flights, provided they change the flight profile - you spend a lot of energy going up to higher altitude, and the essentially glide down.
The energy used to achieve altitude is then saved in the descent stage. So that’s not an issue for aircraft, regardless of how they’re powered. This is why every flight you’ve ever been on climbs to cruise altitude as fast as possible.
High altitude where the air is less dense is better for speed due to less drag. This is also power source agnostic.
Interesting decision to build the whole aircraft instead of the propulsion system only. I wonder what the decision process was between retrofit of existing turboprop frame vs. build from the ground up? I would expect the level of effort and certification to be much higher building from scratch even though you get complete control.
Aircraft design is very intricate. Change the CG, break the whole system.
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.
It may be too hard to do a good retrofit. If you basically have to tear the entire plane apart and rebuild and recertify it to put batteries in the right places, maybe the costs aren’t worth it for potential customers.
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.
Generally all the weight of the fusaage has to go through the wings anyway so it is structurally more efficient to put weight on the wings in the first place.
And they do that with fuel?! Neat!
Yup.
On a 737 they can put about 8k pounds per wing.
Even little planes like Cessnas have wing tanks.
Wow wow!
Might see planes just a smidge differently now :)
In sailplanes we add up to around 200 litres of water to wing tanks in single-seat gliders (empty weight typically around 280kg) to improve the high speed performance (typically up to 270 km/h these days) and ability to fly comfortably in turbulence.
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.
What a rabbithole this is now :D
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...
-
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!!!
I think an interesting aspect is that on normal aircraft fuel tanks have to be near the center of lift to maintain weight and balance as fuel is burned off. When using batteries, this is not really a concern, and I would think might lead to some more interesting designs. To be sure, if there is space in the wing, awesome - the batteries can now also be used as ballast though too if required.
Wings can also be excellent for heat rejection - in-wing batteries have a lot of surface per unit of volume and are constantly exposed to low temperatures.
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.
Probably because they intend to sell aircraft, not electric motors.
Judging by the seats, perhaps making it as light as possible. Existing airframes are relatively light but let's be honest, they aren't trying to save 500g here and there when they have massive jet engines to get everything airborne.
I discussed with people working on aircraft components, and my understanding is that weight is a constant obsession for them. Propose a new system to Airbus/Boeing, and the first question they'll ask is "how much does it weight?"
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.
Agreed. But for related reasons, aircraft aren't really designed for either the structural robustness or balance to deal with big heavy batteries, which is what motivated the clean sheet design.
https://www.latimes.com/business/la-fi-travel-briefcase-unit...
Heart Aerospace (YC W19) just flew the largest electric airplane ever flown — a 100-foot wingspan, a takeoff weight of 25,000 pounds, and $5 of electricity to get it off the ground.
Nit: When they did the actual flight I did the math on the $5 worth of power claim, and it just doesn’t pencil out even at the lowest power rates in North America. Just to illustrate: at $.05 per kWh (which is less than half the price of electricity where they flew), you get 100kwh for $5. 100kw is what it takes to takeoff a 1200 pound Cessna. Probably about 75kw for an efficient cruise in that same plane.
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.
You can't convert between kWh and kW. 100 kWh = 6 MW for one minute... so there is plenty of power if the flight is short enough. They said the plane has 4 Tesla's worth of battery power, let's assume they are 80KWh packs then that's 320kWh that they could use for a short flight. That's a fair amount of juice, they definitely won't be flying long in a 25 ton aircraft without starting up the auxiliary motor but I have no doubt it will be able to get off the ground on $5 worth of electricity.
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.
The specific claim from the company is that the entire 27 min flight was done with $5 worth of power using an all electric power system with a power output exceeding one megawatt.
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.
The takeoff roll is only a minute or so to lift-off, so it's possible. But also somewhat meaningless, as an airplane can take off for free in high-enough headwinds.
"hybrid system (electric + conventional turbo prop)" there's your answer
so for an hour flight it costs $5?
Would be interested to see this compared to the costs to take off a comparable small jet fuel aircraft.
The interesting part to me is that a lot of current electric aircraft development seems to be waiting for battery technology to catch up. They're far ahead in terms of the motors, propeller, electric propulsion control system. The limitation is the battery capacity.
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 first clean sheet airliner to be flown in any category. electric or not, in the US in the last 18 years'
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.
The 737-Max is only not a clean-sheet only because the selling point is pilots don't need to retrain, which is a competitive advantage when selling to airlines.
First time I saw an electric plane with the cowling off was something like this:
https://www.wired.com/story/magnix-electric-plane-motor/
So much simpler.
I wonder if these airplanes are using helium to "reduce the weight"... that is something I also don't usually on drones. Probably too expensive.
I don’t see how a purely electric aircraft could ever beat synthetic jet fuel made with electricity.
If this is a hybrid, I am curious where they are stealing energy from.
It beats it by mostly not using the turbines. The turbines are there for long range diversions which should happen rarely enough to not really matter in terms of carbon release.
Practical challenges aside, I'll gladly file this under "things my physicist dad said would never happen" and call it a win.
Mech eng dad here. He guessed something like this would probably happen, but wasn't betting on it happening so soon.
I was just at Newport Technology preview where they demoed a ground effects aircraft drone. This was a scaled model and the final drone aircraft is designed for 12 passengers. All electric.
https://polaristechbridge.org/bluetide/
https://www.regentcraft.com/
I'm not sure I get the 'appreciating asset' point he makes in the video. How will the plane perform better in 10 years?
Cool stuff regardless!
It won't likely perform better as it ages but it may continue out-performing a fleet that tends to hold its value. If the maintenance cost of the electric motors and batteries along with the turbines operating at reduced power is better than the maintenance cost of two turbines that are operated at 100% power to take off, it could really pay off, as that tends to be a very expensive part of the operation. Airframes also often appreciate these days, as it is very expensive to buy a new one and an old one is somewhat proven.
This plane basically has to outperform a Saab 340.
Turbine powered helicopters can appreciate in value if demand picks up because the tech doesn't move that quickly, as can GA aircraft that are already old because they're all cheap and rudimentary to start off with. (The supposed appreciating asset tends to cost a lot more than the asset appreciation to maintain though...)
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...
That made me double take too, but he must be talking about the software getting better, and thus higher value.
Better battery tech ?
If Teslas could be appreciating assets [0], why not electric planes? /s
If anything, planes have real autopilots!
[0]: https://www.businessinsider.com/musks-claim-teslas-appreciat...
From the video:
Range: 125 miles all electric
In the video he explains that the goal of the hybrid system is mainly to be used when for some unexpected reason the airplane cannot land at its original destination.
There are maybe some advantages to a hybrid system.
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.
I’ve been tinkering with the idea of a hybrid system where the ICE system is its own bolt on component to an electric aircraft that is used for takeoff and altitude before it detaches and returns to the airfield before the aircraft cruiser on electric power. Could even have a rocket launch version for cargo
Separating in flight is a very tricky problem that requires massive amounts of testing and can go very wrong.
They had fuel drop tanks made of paper in WW2.
Cool drones can test and validate the solution without risking a pilot!
You can use some kind of catapult for that
I once saw gliders being launched from a v-8 engine that was mounted on the back of a truck
I also saw this about a year ago: https://www.youtube.com/watch?v=_T9cxv9ubRg
More of a replacement for the "helicopter market"...
The noise wouldn't be significantly lower during takeoff/landing, only during taxi, right? Good for workers on the tarmac, but doesn't get rid of the largest noise pollution issue.
The moment he talked about "remote pilots managing many planes," I closed the tab. Remote pilots sound great until something goes wrong, and things inevitably go wrong, not often, but they go wrong.
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.
> I will never fly on any aircraft that does not have a minimum two-person crew on the flight deck.
You're missing out. Flying solo in a small plane is great.
Indeed, it also is a bit silly: they have enough on their plate just getting this plane type certified.
Thought this was a great watch, as a first time founder myself!
Hybrid! That's what happens when you build new devices around old infra. Steve Jobs didn't design the iPhone around Carriers; it was the other way around.
the concept of electric motors with ultimate "any" fuel flexibility for generators is definitely the future
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)
Agreed, however only fuel for piston engine aircraft is leaded. Not many of them at a large commercial airport. More of a GA issue.
I still find it crazy that piston engine aircraft still run on leaded fuel. The only reason it is still the case is mostly regulatory. We can make compatible unleaded fuel, we could have done it decades ago, but it would have required costly recertification and maybe minor retrofits and the use of additives, and considering the small scale of GA, considered not worth it.
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.
To be clear, this is a hybrid aircraft, but it's still an awesome step forward!
This is awesome! More of this in YC and less Flock's.
Did it fly?
Most of the video is the workshop.
Where is the airplane??
> It's the first clean sheet airliner to be flown in any category, electric or not, uh, in the US in in the last 18 years.
Uh, what about the Bombardier C-series (A220)?
Wikipedia says “It was initially developed by Bombardier Aviation with the program launched on 13 July 2008 and had two years in-service as the Bombardier CSeries.”
Hence 18 years.
Hope it's accurate. Sounds good to be true.
It's true. Good? Nope. This thing will burn giant piles of cash in repairs, and that's not even considering battery replacement, which completely obviates the entire point of this thing.
The interior of the plane is clearly designed by an engineer. They stripped everything down to save weight, passenger comfort be dammed. The seats don't even look comfortable.
They need to hire an actual designer, if the plane weighs 0.5% more but has actual human usability that's worth it.
Really, a prototype airplane, the first of this size ever built with this novel propulsion system, had engineers involved in the design?
You've missed the point. The engineers went too far optimizing for weight, to the point of sacrificing usability.
It’s a prototype. Surely easy access to the structure and equipment is a lot more valuable than nice seats and a finished-looking interior surface.
The company that makes the airplane is not normally the company that installs the interior anyways. The airline that buys the plane typically determines what the interior will look like (stuff like ratio of business to economy, overall # of seats, in flight entertainment, etc)
It being barebones from the factory is not a problem.
What does "usability" mean in the context of a prototype short haul passenger aircraft? It's got seats for people to sit in...
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...
But maybe they’re aiming at short haul cargo. And either way, wouldn’t that really be one of the last things to do? Just proving the plane can even get in the air and stay there for a useful distance on electricity is more important than how comfortable it is.
The video shows dozens of seats, so they are not only aiming for short haul cargo.
And, unsurprisingly, the video also includes speaking where the head of the company says that.
customers buy furniture options when they order the plane.
related : many flight demonstrators in the past for large passenger planes have had no interior at all aside from the cockpit and ballast kits.