9 ms·

Why Electric Airplanes Face Such a Tough Haul [video]

40 points by Stevvo 5y ago

rfreytag 5y ago
Front-Electric Sustainer (FES) is changing the face of gliding: https://news.ycombinator.com/item?id=29703685 https://news.ycombinator.com/item?id=29703685
xyzzy21 5y ago
Their release schedule is laughable and not real. Cessna was proceeded by 50 years of prior art of almost exactly the same vehicle that electric planes do NOT have.
blagie 5y ago
All of these are solvable problems: * With short-hop flights. Swap out batteries at the destination, and slow-charge * Endurance. You don't want batteries discharging below 20%. In an emergency, you do. * Take-off power surge. Super-cap, ground effect, or plug-in power supply during take-off. * I don't think the crash requirements need to compare to commercial aviation, but to cars. This is competing with cars. I'm not saying Joby will get this right, but I think eventually, someone will. A likely mistake seems to be trying to get this off-the-ground in the US regulatory climate. It'd be much easier to do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets after the concept is validated. California seems like just about the worst place to start. As an investment, if you think they have a 1% chance of becoming Tesla, that merits a $10B valuation to be risk-neutral. The investment levels don't seem crazy. Personally, I wouldn't place their odds at anywhere close to 50%, but I'd place them at much greater than 1%.
- hannob 5y ago
  > * I don't think the crash requirements need to compare to commercial aviation, but to cars. This is competing with cars. Noone will accept any new technology that is as dangerous as cars. (And I sincerely hope at some point we will agree that we won't accept an old technology that's as dangerous as cars...)
- Robotbeat 5y ago
  Take off power surge is one of the few areas that electric aircraft actually are well suited for. Batteries of specific power high enough are not uncommon.
  - blagie 5y ago
    The problem raised in the video was that high take-off power draw would age the batteries quickly, not that it was impossible. I haven't run the numbers to see if they were right.
    - Robotbeat 5y ago
      But you’re starting off in the best possible part of the flight, when battery voltage is highest. A burst of power there has the least bad impact. Also, if you have a large battery, the amount of power you can afford for burst is extremely high. It’s also possible to have a battery optimized for high discharge assist the main battery, like a hybrid vehicle. But that’s unlikely for most battery chemistries which have plenty high C-rate that a secondary power-optimized battery is totally unnecessary.
      - Leherenn 5y ago
        Well, if you only do one flight per charge, yes. One of the club around here tried to use an electric plane for instruction, and the constant takeoff/landing cycles killed the battery real fast.
    - _dain_ 5y ago
      Could you have some kind of slingshot on the runway to accelerate the plane, take some of the work off the batteries? Like what they have on aircraft carriers.
    - CoastalCoder 5y ago
      I wonder if a low-performance version of a carrier catapult would work. Perhaps a simpler / cheaper version would be a specialized winch at the end of the runway. Obviously it would limit the airstrips from which an electric plane could embark, but maybe that's an acceptable trade-off.
- Lavery 5y ago
  Just to take issue with one piece of this, the crash requirements do need to compete with commercial aviation, because in the customer mindset they will.
- umvi 5y ago
  > I don't think the crash requirements need to compare to commercial aviation, but to cars. This is competing with cars. A lot of car crashes are not fatal. Would you be able to say the same of electric airplanes? I'm guessing fatality rate will be much higher, and with added collateral damage of a lithium ion bomb falling from the sky onto other cars, buildings, etc. the public will not tolerate electric plane crash rates the same as car crashes.
- EthanHeilman 5y ago
  To me "short-hop flights" is the real reason any of this makes sense. If you are commuting into NYC and can get picked up at 9am and flown past traffic to your building, thats an enormous win if you can pay for it. It will compete in helicopter taxi market and expand that market by being able to land closer to the destination because it makes less noise. This and its faster speed means shorter total commute. Passenger helicopters: speed 160 MPH, range 250 miles, cost $1.3-13.00 USD/mile Joby claims: 200 MPH, 150 miles, ~$4 USD/mile.
  - vkou 5y ago
    Except that NYC is one of the worst environments in the world for short-hop flights, due to the risk of killing dozens of people on the ground if you crash. The safety record of non-commercial aviation is not great. If you want to solve traffic, invest in public transit. Matching the throughput of a single train requires completely saturating the sky with small aircraft.
  - nradov 5y ago
    There are only 3 helicopter pads available for commuter use in Manhattan. Those won't be able to handle much more traffic during commute hours. Building more isn't going to be politically viable. https://www.cnn.com/2019/06/10/us/new-york-city-helicopter-flights/index.html https://www.cnn.com/2019/06/10/us/new-york-city-helicopter-f...
- sokoloff 5y ago
  If I were starting an aerospace company (which is roughly the same as saying “if I hated money…”), I’d damn sure start it in the US. The US has very friendly rules for experimental R&D aircraft development, is the largest single market for aviation, and what the FAA requires for certification of production aircraft isn’t going to be substantially more involved than what they’d accept from another member ICAO state. Aviation regulations are overwhelmingly federal in the US, so excepting any airport-specific rules, CA is an OK place to start. If you’re capable of making electric airplanes viable, you’re capable of doing it in the FAA and CA jurisdiction.
  - xyzzyz 5y ago
    An unrelated reason why California is not great place for it: an aviation company I am familiar with recently had its entire test site (remote, desolate place) closed for months, because of fire risk — one of its previous prototypes caught on fire upon crashing (as things packed with energy sometimes to do on crash), and so no more testing was allowed until things get less dry.
    - nradov 5y ago
      California aerospace companies have usually conducted flight tests in the Mojave Desert area precisely because a crash is unlikely to cause a major fire or other damage on the ground.
  - Gravityloss 5y ago
    If you're in Europe, you could do manufacturing in Italy as they have some kind of a special free trade agreement with USA regarding aircraft. Pipistrel is manufacturing some planes in Italy because of that.
    - Stevvo 5y ago
      Sure, but that doesn't really help anything. e.g. the AW609 mentioned in the video that has been stuck in certification for 20 years is built in Italy under that agreement.
- davewritescode 5y ago
  > A likely mistake seems to be trying to get this off-the-ground in the US regulatory climate. It'd be much easier to do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets after the concept is validated. California seems like just about the worst place to start. Where would this “more friendly” regulatory climate exist and how to you get the best aerospace engineers in the world there? There’s nothing to prevent this company from testing models in California, and unmanned. What’s the point of starting somewhere that lets you kill test pilots with fewer consequences. This is mastabatory libertarian bullshit. No high tech startup wins and loses on regulation.
- oleg_antonyan 5y ago
  > do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets This is brilliant: test in 3rd world b/c who cares about those anyway
- rhinoceraptor 5y ago
  I don't think it would be viable to do battery replacement. Pretty much no commercial EVs do it, partly because we don't need to, and partly because it's pretty hard problem. Battery packs have a pretty narrow range of temperature where they perform well so they need fluid lines to either heat or cool them, in addition to the electrical connections. Plus with a plane, the only place that really makes sense to put the fuel or batteries is in the wings, so it couldn't be a flat pancake battery pack like in a passenger car. I don't think you could make a wing where you can remove the battery from the wing easily, it would have to be sealed in place. So the only way I think that would really make sense would be for the fuselage to be removed from the wing assembly, and then re-attached to a fully charged wing assembly. And that doesn't seem that practical either.
- soneil 5y ago
  > A likely mistake seems to be trying to get this off-the-ground in the US regulatory climate. It'd be much easier to do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets after the concept is validated. California seems like just about the worst place to start. I'm not sure this is as straight-forward as it sounds. Simply put, there's not many places you're going to find a high cash-density with low regulation. Frankly - and I say this as a European - California is exactly where I'd want to launch this. You have the urban density to make it desirable, the cash-density to make it possible, and the most favourable year-round weather out of anywhere else I can think that'd make the list.
  - blagie 5y ago
    Let me give a few examples of decent places to launch: 1) Dubai 2) Doha 3) Maybe Manama 4) Maybe Riyadh Upsides: - "Regulatory regime" means that you talk to the royal family. This is a surprisingly sane and reasonable process. - Plenty of money to go around; people looking for things to invest into when the oil runs out - Better weather than California - Culture is more tolerant of occasional crashes - Cash-rich populations who would pay for this sort of thing The market isn't as large, but for a pilot, you don't want large. For large markets, though, I can think of a few cities in Asia which would be ideal for scaling up. As a footnote: Regulation isn't a question of low versus high. It's a question of easy versus hard. I worked in a highly-regulated field, and we did field testing in a small European country where the standards were probably higher than the US, but the process was much more streamlined. Approvals were done by talking to one expert who either gave a thumbs up, thumbs down, or told you what you needed to change. In the US, the process would have taken years of pushing paperwork, and a mechanical bureaucracy is less suited to evaluate safety than an expert. A multiyear process isn't necessarily any more robust than a fast one.
- euroderf 5y ago
  Take-off power surge: Maybe try catapult launch ? It wouldn't have to be as mechanically compact and precisely manufactured as an aircraft carrier's.
- jillesvangurp 5y ago
  Exactly. Joby is just one of many. They might fail and probably will. The reality: multiple companies are currently flying viable prototypes. A lot of the issues are at this point no longer issues: they are solved problems (or at least very solvable). The solutions might not be perfect but we are beyond proofs of concept at this point: these things are flying. The math is known, brutal, but not a show stopper. In short, within acceptable parameters of e.g. limited range (but also cost), these things can function as advertised. There are a bunch of uncertainties remaining that are essentially non technical and boil down to regulation, market dynamics, and people buying into this stuff. The main psychological issue is that people have been trained to believe that planes are complex machines that require advanced skills to fly, a lot of maintenance, and a high cost per hour/mile. While they are reluctant to let go of these notions, none of that is true for electrical planes. Think of them as a vacuum cleaners with wings and some power source (i.e. batteries or fuel cells). Simple to manufacture, maintain. and operate. Reliable too because there's very little that can break. It's the exact opposite of the complex, unreliable, expensive to build and operate planes that we have today. Their unreliability requires constant vigilance in the form of maintenance, inspections, and vigilance that requires extensive practice and training. You are not even allowed to operate a plane unless you can prove that you have gone through extensive training and have enough recent experience flying a plane. Flying a plane requires deep knowledge of all the complex machinery, its failure modes, and mitigations. Electrical planes not so much. The prototypes on the market right now have in common that they are "fly by wire" where pilot inputs are very limited and dumbed down to the point where you might wonder what the role of the pilot exactly is (some of these things are autonomous from day one). They are mechanically simple (lots of reliable electrical motors, wires, and batteries). And they cost a certain amount of $ per hours which is a function of the (long) mechanical life of the engines and the rest of the plane and the cost of KWH. The main argument in this video is that the FAA is going to be a PITA. That's correct; that's their job and they are good at it. But that doesn't mean it's a constant in the universe. Ultimately some country will start allowing these things and likely at that point FOMO and politics kick in. Simply put, if e.g. China (a likely place for this to happen) starts living in the future by manufacturing and operating these things at scale, there's absolutely zero chance of the FAA being allowed to hold that back in the USA for very long.
leaded_syrinx 5y ago
Hydrogen is the way for aircraft / long-haul vehicles. It's not about conversion efficiency it's about energy density v weight.
- martythemaniak 5y ago
  Electric flight today is always about short-haul flight, ranging from air-taxi eVTOLs like Joby to more normal planes like Eviation's Alice, but all less than 1000km in range.
- umvi 5y ago
  Storing a lot of hydrogen at high pressure requires heavy tanks. Storing a lot of hydrogen at low pressure results in the Hindenburg.
  - ncmncm 5y ago
    So, no one would ever use compressed hydrogen for transport aircraft. LH2 tanks weigh practically nothing.
    - dragonwriter 5y ago
      > LH2 tanks weigh practically nothing. Volume, though, is an issue and impacts aerodynamic design.
      - ncmncm 5y ago
        The weight advantage will prove decisive. On routes served by LH2-fueled transports, the kerosene-fueled dinosaurs will be wholly unable to compete.
    - adgjlsfhk1 5y ago
      you need to either compress or cryogenically cool. At 1atm and normal temp, hydrogen is about 8x less energy per volume then her fuel.
torginus 5y ago
I don't understand why hydrogen fuel cells are not investigated for electric planes - it's a mature enough technology that you can get it in consumer cars, it doesn't suffer from the same weight penalty of batteries. If you put the powertrain of a hydrogen powered Honda Clarity in a Cessna 172, I'm sure it would work.
- acdha 5y ago
  They have been experimented with for decades (I remember reading about 1970s prototypes as a kid in the 80s) but I believe it's stalled on energy density, very similar to batteries. In aircraft, the big factor is storage: if you had a robust storage system you could get more power from burning the hydrogen in a turbine but hydrogen is hard to store safely without very heavy containers.
  - torginus 5y ago
    I remember the Soviets converted a plane for hydrogen combustion: https://en.wikipedia.org/wiki/Tupolev_Tu-155 https://en.wikipedia.org/wiki/Tupolev_Tu-155 But I feel that's a bit of a distraction - turbines must use thermodynamic cycles to convert fuel into thrust - something whose maximum efficiency is less than the real world efficiency of a hydrogen fuel cell. I feel like hydrogen turbofans are not practical for small craft for a number of reasons - cost, maintenance, noise, limited start/stop cycles etc., while electrics have the ability to scale to every aircraft category.
    - baybal2 5y ago
      The maximum efficiency hydrogen to electricity conversion is around on around 50% for real world fuel cells. This is around efficiency of GE90. Your idea will not work. Hydrogen storage, cells, and motors will weights many times the jet engine, or a plane itself
  - ncmncm 5y ago
    An LH2 tank hardly weighs anything. They even put them in rockets. But they take up more room than would fit in the wings. They probably would need to be in nacelles slung under the wings like the engines.
martythemaniak 5y ago
If they didn't face a tough haul, we'd all be flying in them already. I'm very bullish on electric flight, both eVTOL (Joby, Lillium, etc) and normal planes (Eviation, etc), and these things will revolutionize transit the way we can't quite appreciate. Not only will they displace any notions of HSR in developed places like North America (it is already a non-starter, but too many people still have illusions around it), it'll also connect places with HSR-like transit which would never even be considered for a line. By being able to connect a multitude of smaller cities, it'll allow even more out-migration from cities by people with mobile jobs. Number one risk is not technological here, it is likely plain old NIMBYism. I'm sure we'll see a set of contradictory and impossible to meet demands done in the name of "safety" but masking plain old greed, selfishness or just being a reactionary.
- jeffbee 5y ago
  Be serious. HSR is capable of dumping half a million people per hour into stations that occupy less than 100 acres. In no way is eVTOL (which does not even exist!) a substitute good for HSR.
  - martythemaniak 5y ago
    You know the old question "Why go to the moon instead of solving world hunger?" Well, the answer is that despite going to the moon being a incredibly hard technological problem, it is still vastly easier than solving world hunger. Likewise, eVTOLs are a very hard technological problem, but that is nothing compared to the social problems of getting new rail lines built in North America. So yeah, I think the only unserious people are those dreaming of HSR in North America. Vast structural challenges and repeated high-profile failures don't seem to bring about any introspection or doubt, just more doubling-down. Privately built and operated eVTOLs fit smoothly into the structure of our society. Expropriating vast amounts of land to connect city centres while people live in the burbs does not fit nearly so well. Developing better batteries is vastly, vastly simpler and easier than restructuring all of society around fixed rail lines.
    - 5y ago
AnthonyMouse 5y ago
Is there some reason we can't just use biofuels in existing planes? They're more expensive, but they're not that much more expensive. And you could do this immediately instead of having to either scrap every existing plane or wait 30+ years until they all age out. We could at least do this until someone gets electric planes to work, whether or not that ever happens, and continue doing it during the transition. Which would then happen faster when the legacy planes have a higher fuel cost.
- nradov 5y ago
  Yes carbon neutral synthetic liquid kerosene is the clear path forward for long haul flights. It is safe, requires no changes to aviation infrastructure, and has already been tested in civil and military aircraft. https://www.cnet.com/roadshow/news/united-becomes-first-airline-to-fly-passenger-aircraft-using-100-sustainable-aviation-fuel/ https://www.cnet.com/roadshow/news/united-becomes-first-airl... Weight and energy density obstacles will limit electric propulsion to short range flights for the near future. There could also be a use case for hybrid aircraft where electric motors are used to assist the initial take off and climb, then turned off for cruise.
- runarberg 5y ago
  I think the fermentation process of getting the bioethanol is not as carbon-neutral as we hoped. Then there is the issue of monoculture (although that is a problem with more industries). https://www.youtube.com/watch?v=OpEB6hCpIGM https://www.youtube.com/watch?v=OpEB6hCpIGM
- jeffbee 5y ago
  You can just make jet fuel that would work in existing airplanes from renewable sources today. The only problem is it costs orders of magnitude more than fossil fuels.
  - xyzzyz 5y ago
    Not “orders”. Maybe one order. That’s still a lot, but definitely within realm of possible.
- 5y ago
rexreed 5y ago
How will these planes succeed when point-to-point helicopter service has not proven to be a widespread success? What is the key difference between what Joby is planning and Uber's helicopter service (using already FAA approved helicopters and regular fuel)?
- aeternum 5y ago
  Expense is a major factor for helicopters. Helicopters vibrate so much that many require a complete airframe overhaul after some number of hours. From this POV they are actually a very expensive consumable good themselves on top of the high fuel burn required.
  - rexreed 5y ago
    So the economics of the point-to-point air ride hailing industry comes down to the cost of the flying equipment? Given Uber is operating at a substantial loss, is this the primary reason why their Uber-Air service isn't working out? I suspect it's more than just the cost of helicopters and their maintenance.
    - sokoloff 5y ago
      There aren’t that many places where “drive to an airport/heliport [or landowner and local ordinances approved landing area], get flown to another one, and then finish your journey from there” is a massive convenience. Commuting from an office building with a helipad to an airport to catch a private jet? Makes sense if ground transport is 45+ minutes. Building a helipad on your lake property and commuting to the local airport via helicopter? Makes sense if the local airport is 45+ minutes away, but otherwise it seems like a car is a better option. I just don’t see that many helicopter flight pairs making sense to justify having a lot of on-demand helicopters. (And if you don’t have enough to make the latency low, it makes even less sense to the users.)
      - rexreed 5y ago
        So then how would Joby's service be any different than the above? Seems like the same problems to me. Gotham Air attempted this sort of service but went bust, and now the website just bounces to google.com
legohead 5y ago
So this is to help people skip traffic. Assuming it's successful, wont this create new bottlenecks at these pickup/dropoff areas? Reminds me of adding more lanes to a highway. It doesn't really solve anything, just diverts more people to the highway.
- Stevvo 5y ago
  America is obsessed with parking garages. Most cities have no shortage of parking garages whose rooftops could be used as landing sites.
  - runarberg 5y ago
    Wouldn’t there still be congestion in and around these garages then?
    - Stevvo 5y ago
      Large proportions of them are empty because they were built to some municipal code that requires x number of parking spaces for y sq ft of business floor space.
beefman 5y ago
About 20x more expensive at 1/3 the speed vs commercial jet; 40x more expensive at 2x the speed of a car.[1][2][3] Car has 10x the range between refuelings and can stop at almost any building. This will presumably be limited to heliports, of which there are presently ~ 6,000 in the U.S.[4] It's really a quieter / more comfortable helicopter. Helicopters have seen limited use. Will lower noise change that? Edit: The dominant cost factor across modalities seems to be seats per pilot. It's infinite for cars modulo parking; in the hundreds for commercial jets; dozens for busses; single digits for taxis and small aircraft. Of course it's always been understood that ridesharing needs autonomy to be truly profitable, and from the slides it seems Joby acknowledge this as well. Autonomy may be easier in the sky... [1] https://www.youtube.com/watch?v=a717YZnhQ-s&t=700s https://www.youtube.com/watch?v=a717YZnhQ-s&t=700s [2] https://en.wikipedia.org/wiki/Available_seat_miles https://en.wikipedia.org/wiki/Available_seat_miles [3] https://news.ycombinator.com/item?id=19574388 https://news.ycombinator.com/item?id=19574388 [4] https://en.wikipedia.org/wiki/List_of_countries_by_number_of_heliports https://en.wikipedia.org/wiki/List_of_countries_by_number_of...

40 points by Stevvo 5y ago

Front-Electric Sustainer (FES) is changing the face of gliding: https://news.ycombinator.com/item?id=29703685 https://news.ycombinator.com/item?id=29703685

xyzzy21 5y ago

Their release schedule is laughable and not real. Cessna was proceeded by 50 years of prior art of almost exactly the same vehicle that electric planes do NOT have.

blagie 5y ago

All of these are solvable problems: * With short-hop flights. Swap out batteries at the destination, and slow-charge * Endurance. You don't want batteries discharging below 20%. In an emergency, you do. * Take-off power surge. Super-cap, ground effect, or plug-in power supply during take-off. * I don't think the crash requirements need to compare to commercial aviation, but to cars. This is competing with cars. I'm not saying Joby will get this right, but I think eventually, someone will. A likely mistake seems to be trying to get this off-the-ground in the US regulatory climate. It'd be much easier to do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets after the concept is validated. California seems like just about the worst place to start. As an investment, if you think they have a 1% chance of becoming Tesla, that merits a $10B valuation to be risk-neutral. The investment levels don't seem crazy. Personally, I wouldn't place their odds at anywhere close to 50%, but I'd place them at much greater than 1%.

hannob 5y ago
> * I don't think the crash requirements need to compare to commercial aviation, but to cars. This is competing with cars. Noone will accept any new technology that is as dangerous as cars. (And I sincerely hope at some point we will agree that we won't accept an old technology that's as dangerous as cars...)
Robotbeat 5y ago
Take off power surge is one of the few areas that electric aircraft actually are well suited for. Batteries of specific power high enough are not uncommon.
- blagie 5y ago
  The problem raised in the video was that high take-off power draw would age the batteries quickly, not that it was impossible. I haven't run the numbers to see if they were right.
  - Robotbeat 5y ago
    But you’re starting off in the best possible part of the flight, when battery voltage is highest. A burst of power there has the least bad impact. Also, if you have a large battery, the amount of power you can afford for burst is extremely high. It’s also possible to have a battery optimized for high discharge assist the main battery, like a hybrid vehicle. But that’s unlikely for most battery chemistries which have plenty high C-rate that a secondary power-optimized battery is totally unnecessary.
    - Leherenn 5y ago
      Well, if you only do one flight per charge, yes. One of the club around here tried to use an electric plane for instruction, and the constant takeoff/landing cycles killed the battery real fast.
  - _dain_ 5y ago
    Could you have some kind of slingshot on the runway to accelerate the plane, take some of the work off the batteries? Like what they have on aircraft carriers.
  - CoastalCoder 5y ago
    I wonder if a low-performance version of a carrier catapult would work. Perhaps a simpler / cheaper version would be a specialized winch at the end of the runway. Obviously it would limit the airstrips from which an electric plane could embark, but maybe that's an acceptable trade-off.
Lavery 5y ago
Just to take issue with one piece of this, the crash requirements do need to compete with commercial aviation, because in the customer mindset they will.
umvi 5y ago
> I don't think the crash requirements need to compare to commercial aviation, but to cars. This is competing with cars. A lot of car crashes are not fatal. Would you be able to say the same of electric airplanes? I'm guessing fatality rate will be much higher, and with added collateral damage of a lithium ion bomb falling from the sky onto other cars, buildings, etc. the public will not tolerate electric plane crash rates the same as car crashes.
EthanHeilman 5y ago
To me "short-hop flights" is the real reason any of this makes sense. If you are commuting into NYC and can get picked up at 9am and flown past traffic to your building, thats an enormous win if you can pay for it. It will compete in helicopter taxi market and expand that market by being able to land closer to the destination because it makes less noise. This and its faster speed means shorter total commute. Passenger helicopters: speed 160 MPH, range 250 miles, cost $1.3-13.00 USD/mile Joby claims: 200 MPH, 150 miles, ~$4 USD/mile.
- vkou 5y ago
  Except that NYC is one of the worst environments in the world for short-hop flights, due to the risk of killing dozens of people on the ground if you crash. The safety record of non-commercial aviation is not great. If you want to solve traffic, invest in public transit. Matching the throughput of a single train requires completely saturating the sky with small aircraft.
- nradov 5y ago
  There are only 3 helicopter pads available for commuter use in Manhattan. Those won't be able to handle much more traffic during commute hours. Building more isn't going to be politically viable. https://www.cnn.com/2019/06/10/us/new-york-city-helicopter-flights/index.html https://www.cnn.com/2019/06/10/us/new-york-city-helicopter-f...
sokoloff 5y ago
If I were starting an aerospace company (which is roughly the same as saying “if I hated money…”), I’d damn sure start it in the US. The US has very friendly rules for experimental R&D aircraft development, is the largest single market for aviation, and what the FAA requires for certification of production aircraft isn’t going to be substantially more involved than what they’d accept from another member ICAO state. Aviation regulations are overwhelmingly federal in the US, so excepting any airport-specific rules, CA is an OK place to start. If you’re capable of making electric airplanes viable, you’re capable of doing it in the FAA and CA jurisdiction.
- xyzzyz 5y ago
  An unrelated reason why California is not great place for it: an aviation company I am familiar with recently had its entire test site (remote, desolate place) closed for months, because of fire risk — one of its previous prototypes caught on fire upon crashing (as things packed with energy sometimes to do on crash), and so no more testing was allowed until things get less dry.
  - nradov 5y ago
    California aerospace companies have usually conducted flight tests in the Mojave Desert area precisely because a crash is unlikely to cause a major fire or other damage on the ground.
- Gravityloss 5y ago
  If you're in Europe, you could do manufacturing in Italy as they have some kind of a special free trade agreement with USA regarding aircraft. Pipistrel is manufacturing some planes in Italy because of that.
  - Stevvo 5y ago
    Sure, but that doesn't really help anything. e.g. the AW609 mentioned in the video that has been stuck in certification for 20 years is built in Italy under that agreement.
davewritescode 5y ago
> A likely mistake seems to be trying to get this off-the-ground in the US regulatory climate. It'd be much easier to do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets after the concept is validated. California seems like just about the worst place to start. Where would this “more friendly” regulatory climate exist and how to you get the best aerospace engineers in the world there? There’s nothing to prevent this company from testing models in California, and unmanned. What’s the point of starting somewhere that lets you kill test pilots with fewer consequences. This is mastabatory libertarian bullshit. No high tech startup wins and loses on regulation.
oleg_antonyan 5y ago
> do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets This is brilliant: test in 3rd world b/c who cares about those anyway
rhinoceraptor 5y ago
I don't think it would be viable to do battery replacement. Pretty much no commercial EVs do it, partly because we don't need to, and partly because it's pretty hard problem. Battery packs have a pretty narrow range of temperature where they perform well so they need fluid lines to either heat or cool them, in addition to the electrical connections. Plus with a plane, the only place that really makes sense to put the fuel or batteries is in the wings, so it couldn't be a flat pancake battery pack like in a passenger car. I don't think you could make a wing where you can remove the battery from the wing easily, it would have to be sealed in place. So the only way I think that would really make sense would be for the fuselage to be removed from the wing assembly, and then re-attached to a fully charged wing assembly. And that doesn't seem that practical either.
soneil 5y ago
> A likely mistake seems to be trying to get this off-the-ground in the US regulatory climate. It'd be much easier to do this in a friendlier regime, more tolerant of occasional crashes, get experience, and move into Western markets after the concept is validated. California seems like just about the worst place to start. I'm not sure this is as straight-forward as it sounds. Simply put, there's not many places you're going to find a high cash-density with low regulation. Frankly - and I say this as a European - California is exactly where I'd want to launch this. You have the urban density to make it desirable, the cash-density to make it possible, and the most favourable year-round weather out of anywhere else I can think that'd make the list.
- blagie 5y ago
  Let me give a few examples of decent places to launch: 1) Dubai 2) Doha 3) Maybe Manama 4) Maybe Riyadh Upsides: - "Regulatory regime" means that you talk to the royal family. This is a surprisingly sane and reasonable process. - Plenty of money to go around; people looking for things to invest into when the oil runs out - Better weather than California - Culture is more tolerant of occasional crashes - Cash-rich populations who would pay for this sort of thing The market isn't as large, but for a pilot, you don't want large. For large markets, though, I can think of a few cities in Asia which would be ideal for scaling up. As a footnote: Regulation isn't a question of low versus high. It's a question of easy versus hard. I worked in a highly-regulated field, and we did field testing in a small European country where the standards were probably higher than the US, but the process was much more streamlined. Approvals were done by talking to one expert who either gave a thumbs up, thumbs down, or told you what you needed to change. In the US, the process would have taken years of pushing paperwork, and a mechanical bureaucracy is less suited to evaluate safety than an expert. A multiyear process isn't necessarily any more robust than a fast one.
euroderf 5y ago
Take-off power surge: Maybe try catapult launch ? It wouldn't have to be as mechanically compact and precisely manufactured as an aircraft carrier's.
jillesvangurp 5y ago
Exactly. Joby is just one of many. They might fail and probably will. The reality: multiple companies are currently flying viable prototypes. A lot of the issues are at this point no longer issues: they are solved problems (or at least very solvable). The solutions might not be perfect but we are beyond proofs of concept at this point: these things are flying. The math is known, brutal, but not a show stopper. In short, within acceptable parameters of e.g. limited range (but also cost), these things can function as advertised. There are a bunch of uncertainties remaining that are essentially non technical and boil down to regulation, market dynamics, and people buying into this stuff. The main psychological issue is that people have been trained to believe that planes are complex machines that require advanced skills to fly, a lot of maintenance, and a high cost per hour/mile. While they are reluctant to let go of these notions, none of that is true for electrical planes. Think of them as a vacuum cleaners with wings and some power source (i.e. batteries or fuel cells). Simple to manufacture, maintain. and operate. Reliable too because there's very little that can break. It's the exact opposite of the complex, unreliable, expensive to build and operate planes that we have today. Their unreliability requires constant vigilance in the form of maintenance, inspections, and vigilance that requires extensive practice and training. You are not even allowed to operate a plane unless you can prove that you have gone through extensive training and have enough recent experience flying a plane. Flying a plane requires deep knowledge of all the complex machinery, its failure modes, and mitigations. Electrical planes not so much. The prototypes on the market right now have in common that they are "fly by wire" where pilot inputs are very limited and dumbed down to the point where you might wonder what the role of the pilot exactly is (some of these things are autonomous from day one). They are mechanically simple (lots of reliable electrical motors, wires, and batteries). And they cost a certain amount of $ per hours which is a function of the (long) mechanical life of the engines and the rest of the plane and the cost of KWH. The main argument in this video is that the FAA is going to be a PITA. That's correct; that's their job and they are good at it. But that doesn't mean it's a constant in the universe. Ultimately some country will start allowing these things and likely at that point FOMO and politics kick in. Simply put, if e.g. China (a likely place for this to happen) starts living in the future by manufacturing and operating these things at scale, there's absolutely zero chance of the FAA being allowed to hold that back in the USA for very long.

leaded_syrinx 5y ago

Hydrogen is the way for aircraft / long-haul vehicles. It's not about conversion efficiency it's about energy density v weight.

martythemaniak 5y ago
Electric flight today is always about short-haul flight, ranging from air-taxi eVTOLs like Joby to more normal planes like Eviation's Alice, but all less than 1000km in range.
umvi 5y ago
Storing a lot of hydrogen at high pressure requires heavy tanks. Storing a lot of hydrogen at low pressure results in the Hindenburg.
- ncmncm 5y ago
  So, no one would ever use compressed hydrogen for transport aircraft. LH2 tanks weigh practically nothing.
  - dragonwriter 5y ago
    > LH2 tanks weigh practically nothing. Volume, though, is an issue and impacts aerodynamic design.
    - ncmncm 5y ago
      The weight advantage will prove decisive. On routes served by LH2-fueled transports, the kerosene-fueled dinosaurs will be wholly unable to compete.
  - adgjlsfhk1 5y ago
    you need to either compress or cryogenically cool. At 1atm and normal temp, hydrogen is about 8x less energy per volume then her fuel.

torginus 5y ago

I don't understand why hydrogen fuel cells are not investigated for electric planes - it's a mature enough technology that you can get it in consumer cars, it doesn't suffer from the same weight penalty of batteries. If you put the powertrain of a hydrogen powered Honda Clarity in a Cessna 172, I'm sure it would work.

acdha 5y ago
They have been experimented with for decades (I remember reading about 1970s prototypes as a kid in the 80s) but I believe it's stalled on energy density, very similar to batteries. In aircraft, the big factor is storage: if you had a robust storage system you could get more power from burning the hydrogen in a turbine but hydrogen is hard to store safely without very heavy containers.
- torginus 5y ago
  I remember the Soviets converted a plane for hydrogen combustion: https://en.wikipedia.org/wiki/Tupolev_Tu-155 https://en.wikipedia.org/wiki/Tupolev_Tu-155 But I feel that's a bit of a distraction - turbines must use thermodynamic cycles to convert fuel into thrust - something whose maximum efficiency is less than the real world efficiency of a hydrogen fuel cell. I feel like hydrogen turbofans are not practical for small craft for a number of reasons - cost, maintenance, noise, limited start/stop cycles etc., while electrics have the ability to scale to every aircraft category.
  - baybal2 5y ago
    The maximum efficiency hydrogen to electricity conversion is around on around 50% for real world fuel cells. This is around efficiency of GE90. Your idea will not work. Hydrogen storage, cells, and motors will weights many times the jet engine, or a plane itself
- ncmncm 5y ago
  An LH2 tank hardly weighs anything. They even put them in rockets. But they take up more room than would fit in the wings. They probably would need to be in nacelles slung under the wings like the engines.

martythemaniak 5y ago

If they didn't face a tough haul, we'd all be flying in them already. I'm very bullish on electric flight, both eVTOL (Joby, Lillium, etc) and normal planes (Eviation, etc), and these things will revolutionize transit the way we can't quite appreciate. Not only will they displace any notions of HSR in developed places like North America (it is already a non-starter, but too many people still have illusions around it), it'll also connect places with HSR-like transit which would never even be considered for a line. By being able to connect a multitude of smaller cities, it'll allow even more out-migration from cities by people with mobile jobs. Number one risk is not technological here, it is likely plain old NIMBYism. I'm sure we'll see a set of contradictory and impossible to meet demands done in the name of "safety" but masking plain old greed, selfishness or just being a reactionary.

jeffbee 5y ago
Be serious. HSR is capable of dumping half a million people per hour into stations that occupy less than 100 acres. In no way is eVTOL (which does not even exist!) a substitute good for HSR.
- martythemaniak 5y ago
  You know the old question "Why go to the moon instead of solving world hunger?" Well, the answer is that despite going to the moon being a incredibly hard technological problem, it is still vastly easier than solving world hunger. Likewise, eVTOLs are a very hard technological problem, but that is nothing compared to the social problems of getting new rail lines built in North America. So yeah, I think the only unserious people are those dreaming of HSR in North America. Vast structural challenges and repeated high-profile failures don't seem to bring about any introspection or doubt, just more doubling-down. Privately built and operated eVTOLs fit smoothly into the structure of our society. Expropriating vast amounts of land to connect city centres while people live in the burbs does not fit nearly so well. Developing better batteries is vastly, vastly simpler and easier than restructuring all of society around fixed rail lines.
  - 5y ago

AnthonyMouse 5y ago

Is there some reason we can't just use biofuels in existing planes? They're more expensive, but they're not that much more expensive. And you could do this immediately instead of having to either scrap every existing plane or wait 30+ years until they all age out. We could at least do this until someone gets electric planes to work, whether or not that ever happens, and continue doing it during the transition. Which would then happen faster when the legacy planes have a higher fuel cost.

nradov 5y ago
Yes carbon neutral synthetic liquid kerosene is the clear path forward for long haul flights. It is safe, requires no changes to aviation infrastructure, and has already been tested in civil and military aircraft. https://www.cnet.com/roadshow/news/united-becomes-first-airline-to-fly-passenger-aircraft-using-100-sustainable-aviation-fuel/ https://www.cnet.com/roadshow/news/united-becomes-first-airl... Weight and energy density obstacles will limit electric propulsion to short range flights for the near future. There could also be a use case for hybrid aircraft where electric motors are used to assist the initial take off and climb, then turned off for cruise.
runarberg 5y ago
I think the fermentation process of getting the bioethanol is not as carbon-neutral as we hoped. Then there is the issue of monoculture (although that is a problem with more industries). https://www.youtube.com/watch?v=OpEB6hCpIGM https://www.youtube.com/watch?v=OpEB6hCpIGM
jeffbee 5y ago
You can just make jet fuel that would work in existing airplanes from renewable sources today. The only problem is it costs orders of magnitude more than fossil fuels.
- xyzzyz 5y ago
  Not “orders”. Maybe one order. That’s still a lot, but definitely within realm of possible.
5y ago

rexreed 5y ago

How will these planes succeed when point-to-point helicopter service has not proven to be a widespread success? What is the key difference between what Joby is planning and Uber's helicopter service (using already FAA approved helicopters and regular fuel)?

aeternum 5y ago
Expense is a major factor for helicopters. Helicopters vibrate so much that many require a complete airframe overhaul after some number of hours. From this POV they are actually a very expensive consumable good themselves on top of the high fuel burn required.
- rexreed 5y ago
  So the economics of the point-to-point air ride hailing industry comes down to the cost of the flying equipment? Given Uber is operating at a substantial loss, is this the primary reason why their Uber-Air service isn't working out? I suspect it's more than just the cost of helicopters and their maintenance.
  - sokoloff 5y ago
    There aren’t that many places where “drive to an airport/heliport [or landowner and local ordinances approved landing area], get flown to another one, and then finish your journey from there” is a massive convenience. Commuting from an office building with a helipad to an airport to catch a private jet? Makes sense if ground transport is 45+ minutes. Building a helipad on your lake property and commuting to the local airport via helicopter? Makes sense if the local airport is 45+ minutes away, but otherwise it seems like a car is a better option. I just don’t see that many helicopter flight pairs making sense to justify having a lot of on-demand helicopters. (And if you don’t have enough to make the latency low, it makes even less sense to the users.)
    - rexreed 5y ago
      So then how would Joby's service be any different than the above? Seems like the same problems to me. Gotham Air attempted this sort of service but went bust, and now the website just bounces to google.com

legohead 5y ago

So this is to help people skip traffic. Assuming it's successful, wont this create new bottlenecks at these pickup/dropoff areas? Reminds me of adding more lanes to a highway. It doesn't really solve anything, just diverts more people to the highway.

Stevvo 5y ago
America is obsessed with parking garages. Most cities have no shortage of parking garages whose rooftops could be used as landing sites.
- runarberg 5y ago
  Wouldn’t there still be congestion in and around these garages then?
  - Stevvo 5y ago
    Large proportions of them are empty because they were built to some municipal code that requires x number of parking spaces for y sq ft of business floor space.

beefman 5y ago

About 20x more expensive at 1/3 the speed vs commercial jet; 40x more expensive at 2x the speed of a car.[1][2][3] Car has 10x the range between refuelings and can stop at almost any building. This will presumably be limited to heliports, of which there are presently ~ 6,000 in the U.S.[4] It's really a quieter / more comfortable helicopter. Helicopters have seen limited use. Will lower noise change that? Edit: The dominant cost factor across modalities seems to be seats per pilot. It's infinite for cars modulo parking; in the hundreds for commercial jets; dozens for busses; single digits for taxis and small aircraft. Of course it's always been understood that ridesharing needs autonomy to be truly profitable, and from the slides it seems Joby acknowledge this as well. Autonomy may be easier in the sky... [1] https://www.youtube.com/watch?v=a717YZnhQ-s&t=700s https://www.youtube.com/watch?v=a717YZnhQ-s&t=700s [2] https://en.wikipedia.org/wiki/Available_seat_miles https://en.wikipedia.org/wiki/Available_seat_miles [3] https://news.ycombinator.com/item?id=19574388 https://news.ycombinator.com/item?id=19574388 [4] https://en.wikipedia.org/wiki/List_of_countries_by_number_of_heliports https://en.wikipedia.org/wiki/List_of_countries_by_number_of...