Posted by feb 2 days ago
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).
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...
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.
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.
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.
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.
Smaller, lighter, simpler, cheaper, and more flexible about fuel.
https://www.youtube.com/watch?v=NeG4zLlFkak
Linear engine starts around 11:19
Generation II then.
"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.
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
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.
https://en.wikipedia.org/wiki/Energy_density#/media/File:Ene...
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.
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.
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.
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.
A piston or turbine powered aircraft can run all day.
More likely, this replaces the turboprop or commuter jet from Colorado Springs to Denver to catch the connecting fright to any other major airport.
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
The key thing question is whether smaller more frequent flights eat up too much runway time to be economical.
"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...
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.
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.
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.
On a 737 they can put about 8k pounds per wing.
Even little planes like Cessnas have wing tanks.
Might see planes just a smidge differently now :)
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...
-
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!!!
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.
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.
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.
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.
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.
