[HN Gopher] Lilium achieves first main wing transition for all-e... ___________________________________________________________________ Lilium achieves first main wing transition for all-electric aircraft [video] Author : tomohawk Score : 313 points Date : 2022-06-12 15:10 UTC (7 hours ago) (HTM) web link (www.youtube.com) (TXT) w3m dump (www.youtube.com) | dwighttk wrote: | What percentage of available battery did that 4 minute loop take? | _Microft wrote: | I would guess a considerable percentage because launching and | landing takes a disproportional amount of power. Iirc their | information correctly then launching and landing takes 10x as | much power as level flight. That's because in these situations | lift has to be generated by the fans instead of the wings. So | short flights are actually disadvantageous. | 01100011 wrote: | Shower thought: Is anyone working on ground-assisted takeoff of | aircraft using something like an aircraft catapult? It seems like | it would be fairly straightforward to provide the initial | momentum of an aircraft and save a bit of fuel & weight. Sure, | you're not gaining _much_ just getting the aircraft up to takeoff | speed, but it seems like an easy way to make commercial flights | more efficient. | carabiner wrote: | https://www.talyn.com/ | drexlspivey wrote: | I think I am going to stick with the commercial flights without | the catapult if this ever happens | blktiger wrote: | The short answer is that catapult systems are expensive and | require a lot of maintenance. Even many Navies don't use | catapult assisted launches for that very reason. Additionally, | commercial aircraft aren't designed for that kind of force | applied to their main gear. They'd most likely have to be | modified. | chipsa wrote: | Naval catapults don't apply force to the main gear either. | Mostly is to the nose gear now, but it used to through the | use of bridles to points on the wing (and wing spar). The | bridles were a pain though, so they transitioned everything | to the nose gear attachment. You can tell when a carrier | transitioned, because they took the bridle catchers off the | bow (the little narrow ramps at the front). | 01100011 wrote: | I wonder what sort of force you could generate with a series | of electric coils in the ground? It lacks moving parts, so it | should be low maintenance. You'd need magnets on the gear of | the plane, offsetting the weight savings though. Yeah, you'd | definitely need to reinforce the landing gear, but I think | that's doable. | pilot7378535 wrote: | Yes, for gliders: | https://en.wikipedia.org/wiki/Glider_(sailplane)#Launch_and_... | | Also related: https://en.wikipedia.org/wiki/Ground_carriage | yosito wrote: | Last summer, I rode in a Rubik R-26 Gobe glider, invented by | the father of the man who invented the Rubik's cube. | https://en.wikipedia.org/wiki/Rubik_R-26_Gobe | | Pretty fun experience. And if commercial airplanes ever start | using this sort of launching technology, I imagine the | takeoff would feel a lot smoother. | robonerd wrote: | This is kind of cool, but I'm skeptical that these sort of planes | will ever be practical as much more than rich people toys. The | power density of even speculative near-future batteries favors | small airplanes and short flights. This doesn't really mesh into | the existing aviation industry, so proponents of these small | electric planes usually propose creating new markets entirely; | e.g. _Uber for Helicopters_. But I 'm pretty skeptical that laws | will allow regular operation of these in residential | neighborhoods for long, if at all. | | Also, where is the vertical stabilizer and rudder? I assume | they're using differential thrust in powered flight, but what if | they lose power? Can this plane be controlled in a glide? | rklaehn wrote: | The energy density of gasoline does not matter at all. | Batteries are good enough for some applications, like short | distance flights. And the operating costs for use cases where | batteries work _strongly_ favour batteries. | | Power density has not been a problem for a while. We are not | anywhere near the theoretical limits of battery energy density. | So as soon as there are some commercial applications for | battery powered flight, there will be a strong economic | incentive to get closer to the theoretical limits. | | Current jet engines are absolute engineering miracles that go | very close to the physical limits to get maximum efficiency. | But it took several decades to get there. | whatshisface wrote: | There is already a lot of economic incentive for lighter | batteries. | rklaehn wrote: | Yes, and they are improving by a few percent every year. No | major breakthroughs, but compounding improvements year over | year, which do add up. | | Batteries have improved incredibly in my lifetime. As a kid | I had an electric RC plane that barely made it off the | ground. Now you can get pretty cheap aerobatic RC planes | that easily compete with gasoline powered models. | | Battery powered screwdrivers used to be incredibly | underpowered. Now I have a very decent battery powered | rotary hammer... | | https://cdn.arstechnica.net/wp- | content/uploads/2021/05/bnef_... | robonerd wrote: | > _The energy density of gasoline does not matter at all._ | | Well if we're talking about commercial aviation, we're | talking about jet fuel not gasoline. Regardless, it obviously | matters a lot. A fully loaded 747 freighter has somewhere | around 200 tons of jet fuel and a max payload of about 130 | tons. They already need more fuel than cargo, and that's | _with_ the excellent energy density of jet fuel. Furthermore, | traditional planes get lighter the longer they fly as they | burn off their substantial fuel loads. The last 20% of the | fuel goes a lot further than the first 20%. Batteries don 't | get this advantage at all. (Dropping batteries from the plane | with parachutes is a terrible idea, but I've lost count of | the number of times I've seen it proposed..) | | > _We are not anywhere near the theoretical limits of battery | energy density._ | | This doesn't jive with what I've read. It's my understanding | that we're already near the limits of what electrochemistry | can give us, and future advancements are likely to come from | improved electrode designs, with maybe 2-3x better | performance possible if we're lucky. | tremon wrote: | _Dropping batteries from the plane with parachutes is a | terrible idea, but I 've lost count of the number of times | I've seen it proposed_ | | Perhaps, but there is also the middle-ground solution to | use a booster rocket assembly similar to what the space | shuttle uses. The booster can use its own battery packs and | if needed its own additional engines, and when the plane | has reached cruising altitude, the booster can decouple and | return to the airport of departure. | rklaehn wrote: | > Well if we're talking about commercial aviation, we're | talking about jet fuel not gasoline. Regardless, it | obviously matters a lot. A fully loaded 747 freighter has | somewhere around 200 tons of jet fuel and a max payload of | about 130 tons. | | You only need giant quantities of kerosene for transoceanic | or transcontinental travel. The lilium business model | requires a range of a few 100 km, which is possible with | today's batteries. | | Very long distance air travel is impossible with today's | commercially available batteries, but is possible with | exotic chemistries (see below) or with hydrogen fuel cells. | | > This doesn't jive with what I've read. It's my | understanding that we're already near the limits of what | electrochemistry can give us, and future advancements are | likely to come from improved electrode designs, with maybe | 2-3x better performance possible if we're lucky. | | There are several battery chemistries such as lithium | sulfur or lithium air that have extremely high energy | densities. But cycle life remains very low, which makes | them uneconomical. | | There has been decent progress made in improving cycle | life, but it is still too low to be economical. There are | military applications where a low cycle life is acceptable. | robonerd wrote: | > _a range of a few 100 km, which is possible with today | 's batteries._ | | Not with a meaningful amount of cargo it isn't; look up | the electric planes that are actually flying today (and | it's certainly not for want of trying, this is a very | trendy field.) I can think of only a few niches where | very light but expensive cargo _needs_ to go somewhere | close-by, but faster than is possible with a truck. | Organs for transplant, and rich people. | FullyFunctional wrote: | The cargo here is humans | robonerd wrote: | But can you carry enough of them to make the whole thing | worth it? | DennisP wrote: | It used to mesh a lot better, when general aviation was much | bigger than it is now and we had lots of tiny airports. Maybe | we could get back to that. VTOL makes it a bit easier. | nradov wrote: | If you have even a tiny airport with a real runway then you | can operate fixed-wing aircraft (possibly electric powered) | without the extra cost and risk inherent to VTOL. Lillium and | their competitors in the e-VTOL space are trying to create a | new market for urban air mobility by bypassing airports and | building new heliports, but even if they can solve the | technical and legal challenges it's unclear if the economics | will work. | nradov wrote: | Powered lift aircraft are not controllable in a glide, nor are | they capable of autorotation like a helicopter. Any complete | loss of power will result in an unrecoverable spin. For safety | these aircraft rely on redundant systems, plus a parachute. | | Finding landing sites is going to be a major challenge even if | they can solve the battery problems. New York City could be a | prime market but there are only a few heliports. Politics and | safety issues make it difficult to construct more. | robonerd wrote: | > _New York City could be a prime market but there are only a | few heliports._ | | Afaik rooftop helipads have been banned in NYC ever since an | accident in 1977 killed five people. | merely-unlikely wrote: | There are three heliports on the rivers around Manhattan. | There's plenty of space to build more but noise complaints | prevent that from happening. Bezos wanted to build one on | the Queens waterfront (LIC) but the city killed the idea. | bluejekyll wrote: | Any idea what the minimum height for the parachute to be | effective as a life saving device? | nradov wrote: | Minimum effective altitude for parachutes on light aircraft | is about 400 ft agl, but the exact number varies depending | on the flight regime. For powered lift aircraft there is | likely a small "dead zone" in the flight envelope: too high | to survive a crash, too low for the parachute to be | effective. This may or may not be acceptable depending on | mission risk tolerance and the reliability of other | systems. | | https://www.aopa.org/news-and-media/all- | news/2018/march/flig... | GordonS wrote: | > too high to survive a crash, too low for the parachute | to be effective | | This is probably a silly question, but couldn't the pilot | just wait until the plane dropped below the dead zone | before deploying the parachute? | Andrew_nenakhov wrote: | The lower the craft drops, the deader the zone. | chipsa wrote: | You're thinking about the dead zone in the wrong way: | There's a height X where you can drop the aircraft and | it'll absorb all the forces to have the people live. | There's a height Y where the parachute has enough time to | deploy and bring the aircraft to terminal velocity. If X | is less than Y, there's a height where there's nothing to | save you. | | Options to resolve this are: make X higher by making the | structure able to absorb more energy, or make Y lower by | having it deploy faster. | jeffbee wrote: | The Cirrus SR22 needs ~1000ft above ground to effectively | deploy the airframe parachute in a spin. | Simon_O_Rourke wrote: | I'm guessing that if it loses power during flight then it's | curtains for the airframe and anyone unlucky enough to be in | it. | | There's lots more work to do to push it out to the mass market, | but I could definitely see a niche for it. | themitigating wrote: | That's the same if a jet engine losses power | CoastalCoder wrote: | The movie Sully [0] opened my eyes to the amazing glide | ratio of a commercial passenger plane like the A320. (I'm | assuming that the movie was pretty accurate in that | regard.) | | [0] https://en.wikipedia.org/wiki/Sully_(film) | nradov wrote: | Yes, the movie was accurate in that regard. | t0mas88 wrote: | Passenger jets have very good glide ratios. A 747 gliding | with no power (all four engines somehow broken) from | 10,000ft will get even further than a small Cessna 172 | doing the same. | | This is counter intuitive to even most pilots, but it's how | efficient the wing design on a passenger jet is. Their lift | to drag ratio is better than small planes. | fullstackchris wrote: | Is this achievable by the size of the craft itself? Or | the fact that these bigger planes have 1000s of engineers | behind them optimizing every possible factor to squeak | out the best possible lift to drag ratio? | p_l wrote: | Nope. | | Look at the tiny wings, and at what speed it still depended | on vertical thrust. It's going to have _horrible_ glide | ratio, which means unpowered landings might be, well, not a | thing, which leaves you only with emergency full-plane | parachute as an option. | | Pretty much all jet engine planes can do unpowered landings | in glide, though admittedly some have pretty high speeds | involved - but then they operate by default only on | airports that have facilities for such speeds. | oliveshell wrote: | See this famous example, where a jet airliner ran out of | fuel in flight and glided to a successful landing: | | https://en.wikipedia.org/wiki/Gimli_Glider | kayodelycaon wrote: | Also Air Transat Flight 236. | https://en.m.wikipedia.org/wiki/Air_Transat_Flight_236 | sokoloff wrote: | If a [civilian] jet aircraft loses an engine, it's still a | strong favorite to end that flight upright, intact, and on | a runway. There are a couple dozen jet engine failures per | year; the overwhelming majority end up in a safe | conclusion. | | https://www.cbsnews.com/news/jet-engine-failures-rare- | usuall... | mrfusion wrote: | Why not add a parachute? Some small planes actually build one | in. | merely-unlikely wrote: | I like those a lot but they only help above some altitude | (I think it's something like 300 or 600 ft). Ie they won't | save you during VTOL | codingdave wrote: | Airplanes glide. Some better than others, but they do glide. | hn_throwaway_99 wrote: | That's the whole point of GP's comment. Planes glide with | the control afforded by a rudder and a vertical stabilizer. | Without that, it ain't pretty. | nradov wrote: | Powered lift aircraft are not controllable in a glide, nor | are they capable of autorotation like a helicopter. Any | complete loss of power will result in an unrecoverable | spin. For safety these aircraft rely on redundant systems, | plus a parachute. | kayodelycaon wrote: | I think this "plane" has a glide ratio that's only slightly | better than a thrown rock. | crubier wrote: | If they aren't stupid (And I bet they aren't), they made | several independent redundant power system. I think | distributed power systems (i.e. lots of small engines) is | actually on of Lilium's main strength, can be made very | reliable. | | Lost 2 batteries and 7 rotors, fine, there's still 6 | batteries and 25 rotors left. Or something like that | barnabask wrote: | Check out their other video posted around the same time as | this one, especially the part about changing the wheel design | to allow for rolling landings. Seems like regulators had the | same concern. | | https://youtu.be/qZ73PftBfFg | toomuchtodo wrote: | Enjoy the engineering achievement in the moment. | kurthr wrote: | A lot of the electric (mostly fuel cell) aviation startup | industry is funded/supported by currently profitable aviation | companies. The 1000hp motors for them are, like the airframes, | one of the mostly off-the-shelf elements of their development. | | I agree that even modern batteries are pretty absurd for any | human scale flight, though scaling laws make smaller aircraft | more reasonable. | amelius wrote: | Isn't synthetic fuel much more promising? | jeffbee wrote: | Yeah they are, and this fact is just overlooked by people | who aren't thinking through the implications of abundant | renewable energy. With a surplus of renewable energy it | makes much more sense to manufacture synthetic liquid fuels | and burn them, than it does to power airplanes with | batteries. The energy cycle is grossly inefficient but | nobody is going to care because the energy inputs will be | nearly cost-free. | zbrozek wrote: | CAISO hits about 100gCO2e/KWh during the day. And I run a | solar surplus that I don't put back on the grid. | | I'd be really happy if there were a good way for me to | turn excess electricity into something I could use later. | Maybe that's hydrogen. Maybe that's capturing carbon and | putting it into liquid fuels. Maybe that's creating | graphite that I can use for fun personal projects. | | But regardless, I don't expect grid electricity prices to | fall. Probably not in the US. Definitely not in CA. | frosted-flakes wrote: | I had that thought recently. Renewable energy sources | like wind need a lot of energy storage. That is, unless | you over-provision them so much that they can always meet | demand even at peak times. This leaves you with over- | production at other times, which could be used for other | purposes that don't need to run continuously: synthetic | jet fuel production, water desalination, etc. | | Basically, overprovision and then set electricity rates | based on demand, and the renewable energy "storage | problem" might just sort itself out. Of course, all those | windmills and solar panels will cost an awful lot, so it | might not be as simple as "overprovisioning". | Sebb767 wrote: | > That is, unless you over-provision them so much that | they can always meet demand even at peak times. | | Overprovisioning solar to power the grid on ice cold, | windless new moon night is going to be hard. Having | somewhere to put excess energy and some overprovisioning | is always good, but it won't solve all storage problems. | robonerd wrote: | From a CO2 perspective, synthetic fuels don't have an | intrinsic advantage, unless you use biomass as your source | of carbon. Traditionally, synthetic fuel has been made | using coal or natural gas as the source of carbon. There is | still some advantage to this, the nitrogen and sulfur | content of the fuel can be dramatically reduced, which is | great. But with regard to C02 specifically, you're | basically burning coal. With biofuels, I think care needs | to be taken to ensure we don't ruin the price of food for | people by incentivizing farmers to grow fuel feedstock | instead. Biofuels made from algae might be the best, since | this wouldn't require the use of arable farmland. | | Another approach is to pull the CO2 straight out of sea | water. Apparently the US Navy thinks this might be a viable | approach, since their nuclear aircraft carriers have power | to spare. | ginko wrote: | I believe when people say synthetic fuel they mean carbon | neutral fuels that are made from renewable electricity. | | The general idea is to use electrolysis to produce | hydrogen, then combine that with atmospheric CO2 to | produce methanol. | | For instance: https://www.efuel-alliance.eu/efuels/what- | are-efuels | robonerd wrote: | Atmospheric carbon capture seems like an petroleum | industry scam to me (check the 'Members' page of that | website.) In principle it's what plants do, but plants do | it using scale; there's a whole bunch of them. CO2 is | under 500ppm in our air, and air isn't particularly dense | in the first place; the amount of air you'd need to move | through your capture plant is immense. | | On the Costs & Outlook page of this site, they list their | potential feedstocks; it's all biomass, except for the _' | Technical Potential "Unlimited"'_ column, which mentions | Power-to-Liquids. But how does that actually work and | does it actually make sense? | | Related parody of carbon capture: | https://www.youtube.com/watch?v=MSZgoFyuHC8 | PaulHoule wrote: | It is possible, it's just expensive. | | The U.S. navy is interested in a fuel synthesizer that | works on co2, seawater and uranium and they can pay more | than you per gallon because you don't have to refuel an | aircraft carrier in a war zone. | sky-kedge0749 wrote: | I recently commented about synthetic jet fuel in another | thread https://news.ycombinator.com/item?id=31704829: | | > A problem with biofuel is scaling it up, see: | https://ieeexplore.ieee.org/document/7498153. According | to that article the U.S. would need to devote "an area | bigger than Texas and California and Pennsylvania | combined" to crops specifically for its own jet biofuel | needs. That's just for flying, not for food or fuel for | ground transportation or anything else. | | Also that article says that from 2009-2013 a $100 million | effort was made to figure out how to get sufficient | synthetic fuel from algae but they eventually gave up and | went back to the drawing board. | ncmncm wrote: | Biofuel is an obvious dead end. | | The future has no place for biofuel in any substantial | amount. | ncmncm wrote: | _Obviously_ in the present context "synthetic" refers to | fuel produced using renewable energy. If you are willing | to use petroleum, you don't need to synthesize anything | because that is where you started, unless maybe you are | turning NG into kerosene. But that would be a dead end | technology, so would not return investment. | | Energetically, the principal synthetic fuels will be | anhydrous ammonia and hydrogen. Capturing CO2 to make | methane and kerosene is possible but more expensive. In | particular, you need hydrogen as input, and must both | capture and crack the CO2. | | But for some uses you still need hydrocarbons, at least | for now. Given carbon taxes subsidizing synthetics, the | synthetics could be competitive. | | In the longer term, aviation does much better with liquid | hydrogen fuel, but it takes new airframes or, at least, | extensive retrofits. | systemvoltage wrote: | Can we allow CO2 emissions if we can sequestrate it | somewhere else? Synthetic fuels sounds like a good idea. | | It's capturing energy in point A and being used at point | B. You can't just look at point B and yell "CO2 | emissions!". | robonerd wrote: | > _if we can sequestrate it somewhere else?_ | | That seems to be the big _if_. | systemvoltage wrote: | https://en.wikipedia.org/wiki/Carbon_sequestration | hannob wrote: | There's been an EU funded research project that did some | projections on the electricity needed for e-fuels. See the | graphic on page 44: https://www.fch.europa.eu/sites/default | /files/FCH%20Docs/202... | | For pure e-fuels they project 32 PWh. That is, to put it in | perspective, more than the total world electricity | production today. You'll want to use every technology | available to do this in a more efficient way - batteries | for very short ranges, hydrogen for mid ranges, e-fuels | only for long range where nothing else works. It'll still | be very challenging and likely the current growth | projections of the aviation industry will be seen as | unrealistic fantasies at some point in the future. | lukeschlather wrote: | > For pure e-fuels they project 32 PWh. That is, to put | it in perspective, more than the total world electricity | production today. | | Total annual electricity production is 161 PWh. THe PDF | you linked puts it in perspective by saying that if it | were purely powered by renewable energy it would increase | the size of the renewable energy sector by 3 to 5 times. | In other words this doesn't sound hard at all from an | electricity standpoint. If electrical generation were | half the cost it would be economical right now. | moby_click wrote: | From https://pubs.rsc.org/en/content/articlelanding/2020/ | se/c9se0... | | > We find that an electricity emissions factor of less | than 139 g CO2e per kW h is required for this [Direct Air | Capture system paired with Fischer-Tropsch synthesis] | pathway to provide a climate benefit over conventional | diesel fuel. | | The grid averages in most regions are higher than that. I | don't think multiplying current renewable generation just | for jet fuel is easy. | bbojan wrote: | Burning any fuel in our atmosphere produces nitrous oxides. | Synthetic/carbon neutral fuels won't help with that. | SoftTalker wrote: | These can possibly be addressed by catalytic converters | in the exhaust (not sure how feasible that is in a | turbine engine though). In any event, it's a small | fraction of total greenhouse emissions, dwarfed by CO2. | Let's not let perfect be the enemy of good. | bbojan wrote: | Oh I wasn't concerned about their greenhouse effect | contribution. NOx can cause asthma and bronchitis and can | aggravate pre-existing heart conditions. They also form | smog. | | Did I mention that they are bad for the ozone layer? | kkfx wrote: | This might give you some insights... | | https://www.easa.europa.eu/sites/default/files/dfu/uam-full-... | | ...of the idea. Witch is essentially, advertisement aside, "the | wealthy who happen to live nearby cities, witch happen to be | open-sky prisons^w^w factories stuffed with services to achieve | the Chinese lockdown with workers who live in the factory, to | work, of course ehrm, to achieve the best work life balance | (better not say the best to who) can came and go from such erh | smart cities in full comfort with means that made things | closer, like if they live inside the city and goes with cars. | | ...In the LONG term, that means we can benefit from the economy | of scale living "near" but far less dense than today so at that | point in time we have finally found a way to live sufficiently | flexible to withstand the technological, social and climate | change still being near enough to be social and have economy of | scale phenomenon. | | Or: in the short term we need a good solution for those who can | pay, in the medium terms slaves ahem citizens have built a new | society and new generations will finally benefit from such | progress... | | In theoretical terms: maintaining roads network is expensive, | far expensive if we also need to build new ones, like a | potential future arctic "anthropization" due to climate change, | so better made few railroads and waterways for heavy loads | transports and live humans in the air, far more flexible and | cheap. At a certain point in time if we are still alive as a | species we will reach that point. Then the "self-sufficiency | push" will be the key to reach that goal in an unspecified | future. | | Ps if they loose power there is AFAIK only an emergency | parachute for the entire plane. Only it demand, I suppose, a | certain altitude to being able to be deployed... | newaccount2021 wrote: | ramesh31 wrote: | >This doesn't really mesh into the existing aviation industry, | so proponents of these small electric planes usually propose | creating new markets entirely; e.g. Uber for Helicopters. But | I'm pretty skeptical that laws will allow regular operation of | these in residential neighborhoods for long, if at all. | | I can see it becoming more of "Greyhound for Helicopters". | Practically every town in the US greater than a few thousand | population has at least a local municipal airport. With | electrification, aviation can become so cheap that all of these | fields will just have a few commuter size electric aircraft | that feed into to the rest of our existing airport | infrastructure. And with the planes being so small, there's | really no need for TSA security or anything, it becomes as | simple as buying a ticket on your phone and hopping on the | plane like a bus. | repiret wrote: | > With electrification, aviation can become so cheap... | | Fuel is not the dominant cost in general aviation. | Electrification alone won't make it cheap. | ramesh31 wrote: | >Fuel is not the dominant cost in general aviation. | Electrification alone won't make it cheap. | | It's not about fuel efficiency. In fact, any electric | aircraft with current battery tech is always going to be | less efficient than a jet, because jets burn oxygen from | the air. | | It's about maintenance. The fixed hourly cost of aviation | is almost entirely based on the cost of maintenance. And a | fleet of electric aircraft will be orders of magnitude | cheaper to maintain than turboprops and jets. That can | unlock whole new business models of small scale commercial | aviation that aren't possible today. | nradov wrote: | When you say "orders of magnitude cheaper" you can't | possibly mean even 10x. There is more to aircraft | maintenance than just engine repairs and overhauls. | Electric aircraft will still require similar amounts of | maintenance on the airframe, control surfaces, avionics, | and interior. And some of the powered lift designs have | literally _dozens_ of separate motors and rotors, each of | which require periodic manual inspection. | 908B64B197 wrote: | > And with the planes being so small, there's really no need | for TSA security or anything | | There's no need for larger planes either for zero-risk | travelers. | [deleted] | akira2501 wrote: | Granted, this is a new type of transport.. but the current | metrics on air flight safety do not support this idea. Take | offs and landings are the most dangerous part of flight, and | still account for planes being more dangerous _per trip_ than | most other modes of transport. | | Planning to create a plane that fills this space is planning | to create a plane that suffers a lot of accidents for almost | no real gain over current options. | | Buses are incredibly safe. If you want better busses, build | those instead. This obsession with floating to your | destination above the ground does not seem wise or | worthwhile. | ghaff wrote: | It's trivial to create a luxury "bus" in just about any | form factor you want to from a full-size motor coach down | to a limo. Presumably the economics don't work in most | cases. Of course, if you're talking small municipal | airports in the US, the vast majority of people living | there, especially those who can afford somewhat upscale | transportation, probably own a car. | SoftTalker wrote: | Yes. Most small towns don't even have bus service to the | nearest hub airport, because economically it doesn't | work. And there is no arrangement of costs that will work | out to electric aircraft being cheaper to own and operate | than a bus. | freemint wrote: | In a sufficiently river/sea/ /hill/valley rich | environment it might work if one can save on | infrastructure cost for extra expensive roads. This is | not most of the world though. | nradov wrote: | Electrification alone won't make air charters cheap. The | aircraft themselves, pilot salaries, maintenance, and | facilities will all still be nearly as expensive. We are | decades away from the FAA allowing autonomous or remote | piloted aircraft to carry paying customers in commercial | service. | theptip wrote: | This was posted on HN a while ago; of course the numbers are | aspirational but this explains their business model: | | https://lilium.com/newsroom-detail/why-regional-air-mobility | | > If we imagine for a moment that you work in an office in Palo | Alto, you could now choose to live in Hayward (5 min flight, | $25), downtown San Francisco (10 min flight, $50), or even San | Rafael (15 min flight, $70). | | > Or maybe you want to escape to Lake Tahoe for a long weekend? | That would be less than an hour on a Lilium Jet, at a cost of | around $250 at launch and less in the near future. It might not | be something you'd do every weekend, but saving you three hours | each way might well make it worthwhile for an occasional trip. | | Obviously at first this will be a luxury good, but it's not | obvious that it'll remain out of reach for the middle class. | (Sure, it'll never be cheaper than a bus.) | | It's a fair question exactly how much regulatory change this | approach requires, but my impression is that they are trying to | operate within existing constraints (I'd appreciate any insight | from experts in the aviation space though). | bufferoverflow wrote: | You would have to be making a lot of money to justify 2 such | flights per day. | | 25 * 2 * 22 = $1100/mo = $13.2K / year. | bpodgursky wrote: | Bay bridge toll + gas + parking + amortized car ownership + | insurance is pretty plausibly less than that already. | Sebb767 wrote: | You will have less mobility than with a car, though,so it | won't replace all of it. But I agree with your main | point, the actual premium will be much lower and probably | worth it, considering the time saved. | mbreese wrote: | But if you can live in a cheaper place than Palo Alto, | you'll make back that $15K per year in lower house | payments. And if you only have a comfortable commute of | 15-20 min each way as opposed to an hour (or more), your | standard of living will be much nicer too. | trompetenaccoun wrote: | There's likely a reason they picked Switzerland, Munich, | New York and California as examples ;) | | I'm interested in how those prices break down. Without any | more details, it's hard to know if they're realistic at | all. | sydd wrote: | The main issue is not cost, but safety and the disturbance of | others. | | Safety: If you crash in a car, its very likely that you | survive. With these a crash is very likely deadly. To reach | safety levels like commercial airplanes costs will need to | rise tremendously. A commercial jet needs maintenance and | checks after each flight by trained personnel, high quality | parts that can be tracked from the refinery,... | | Privacy: You dont want these flying over your house 7/24. | They fly much lower than commercial planes, with a mediocre | camera you could spy on anyone. | | Crime: What if you divert one? Will there be security | checkpoints at the entrance? | | Weather: I'm no aviation expert, but these look... flimsy. | Are they able to run on cold weather? (batteries last much | less in cold) Are they able to run in storms? Likely not, | even commercial planes avoid them. Then I guess they suspend | the service during storms, since with their "local" distances | as big as the circumference of a storm cloud? | hef19898 wrote: | Safety and weather are covered by certification | requirements. Those will be somewhere between small | aircraft and helicopters with some eVTOL specifics. If it | gets certified those bases are covered. | | Privacy: Regulated airspace is your friend, plis why wait | for one those if you can have your own drone for the price | of one Lilium ticket. | | Crime: Regulations also cover airport operations, so that | base will be covered as well. | | For me the question is not _if_ those aircraft are goong to | fly (they will if it os technically possible and people | fund development), but rather whether there is an actual | market for those big enough to make the manufactirers and | operators viable businesses. The last qiestion is hard | (IMHO impossible) to answer without getting them to market | first. | sokoloff wrote: | There are certification requirements for both the | aircraft and Ops Spec approvals for Part 135 (on-demand | charter) operations. I can see that these would be | certified to fly (and thus eligible for Part 91 (private) | operations) far more easily than the more stringent | requirements for Part 135 charter operations. | | The FAA thinking is that you have greater understanding | as a passenger on a Part 91 operation and are better able | to judge the risk yourself, whereas a Part 135 (charter) | or Part 121 (scheduled airline) operation, the public | cannot effectively judge the safety of the operation so | the FAA holds them to a higher standard. | | Single engine Part 135 is possible, but there's a large | amount of focus on redundancy: | https://www.aviationconsumer.com/industry-news/single- | engine... | sokoloff wrote: | These seem to compete more in the helicopter realm than the | airliner realm. That's likely to be true of the relative | level of safety of this vs a helo vs an airliner. (I've | sometimes quipped that helicopters are one of the primary | predators of billionaires.) | | While the stated/projected costs (which I doubt will be | achievable), these would compete very favorably against a | helicopter on a cost basis. Without the ability to auto- | rotate (or a functional equivalent level of safety system), | there's no way I'm getting in one nor recommending my | family get in one [and I'm perfectly happy flying single | engine piston aircraft at night]. | lambda wrote: | I work for one of these startups, Beta. | | We are focusing on a slightly different market than the | other entrants; we're focusing initially on cargo rather | than passenger transit. One initial customer is United | Therapeutics, for transporting organ transplants and | artificial organs to hospitals. Another is UPS, for getting | air freight from airports to distribution centers; cutting | out the truck trip can save a ton of time there. We are | also making a passenger variant, but since the regulatory | and NIMBY concerns for the passenger air taxi market | present a lot of risk, we're not betting solely on that | market like a lot of the other companies are. | | This helps with a lot of the concerns raised in this | thread. In fact, another one that I'm not sure has been | brought up is vertiport design and siting concerns; right | now standards on vertiports are still a work in progress, | and there are questions about whether it will be feasible | to get them installed, because even with vertical takeoff | and landing you generally need to keep approach angles of | about 15deg clear, which means once a vertiport is | installed you need to limit the heights of any surrounding | buildings to keep the approach clear. | | To address a few of your other concerns: we're located in | northern Vermont, we know cold weather. Actually, for our | use case hot weather tends to be more of a concern; | batteries and motors heat up when used, especially in the | very high power vertical lift phase, so our limitations | there tend to be thermal and cold air provides better | cooling. | | Our charging stations also include air for cooling and | warming the batteries; so you should be able to avoid the | issues with batteries being cold on startup with our air | system. | | All aircraft have limitations on weather that they can be | flown in; crosswind limits for takeoff and landing, etc. As | very lightweight aircraft, with high lift/drag, these will | be somewhat lower than the limits for your big jumbo jets, | but will be high enough to be useful in a lot of weather. | All aircraft have requirements for design and testing for | HIRF (high intensity radiated field/lightning), so these | will all be certified to the same standard there. Aircraft | can optionally be certified for flight into known icing | conditions (FIKI); I believe our plan is to have the | capability, but as an optional add on, as it requires a | number of heating elements which add weight and complexity. | But overall, the weather concerns shouldn't be too much | different than for other small aircraft. | | As far as safety goes, that's obviously a concern in any | aircraft. One advantage of electric aircraft is that | electric propulsion systems are far mechanically simpler, | with far fewer moving and wearing parts. The only real wear | item of concern are the main bearings on the motors, and | the landing gear. So maintenance intervals can be much | longer than with ICE aircraft, and I expect reliability to | be considerably higher. Additionally, electric motors can | be much smaller and lighter, and thus can be made | redundant. Each propeller on our aircraft will be driven by | multiple independent motors (probably can't say the exact | configuration at the moment), so that motor failures can be | tolerated without catastrophic consequences. | mike_hock wrote: | I mean, why should regulations me more lenient on sci-fi | chopper/plane crossovers than on regular choppers? | dkasper wrote: | Zero chance of helicopters in cities after 9/11. You can't fly | helicopters over SF or Manhattan anymore except for medical | purposes. | mlyle wrote: | Helicopters aren't banned over Manhattan, etc, despite | repeated efforts to do so. | | In the late 1970's, all the building-top helipads stopped | operation after repeated accidents. | | Still, there's the helipads along the river and a VFR | corridor in and out of Manhattan. In 2009, the altitude rules | for the corridor got a lot stricter because of repeated fatal | accidents. | merely-unlikely wrote: | I was under the impression you can only fly over the | rivers. Is that not true? | mlyle wrote: | There's a VFR corridor over the rivers where you don't | have to talk to air traffic control. Otherwise, you're | going to need to talk to LaGuardia. | | If you're a tour operator and want to use a city | heliport, you need to sign a very restrictive agreement | about operations, too-- which allows only limited | overland stuff (e.g. flying over Yankee's Stadium/the | Bronx). Mostly because people were sick of tourist | helicopters constantly hovering over Central Park. | | https://cityroom.blogs.nytimes.com/2010/04/30/rules- | tightene... | | None of this has anything directly to do with 9/11. | Crashes of tourist helicopters and noise concerns has | caused the city to clamp down on use of helipads. Crashes | of air taxi operations in the 1970s caused the removal of | the vast majority of helipads. | rklaehn wrote: | There are also big cities outside America. Plenty of | helicopters in Sao Paulo... | | https://www.youtube.com/watch?v=uiybWbyfQIY | lastofthemojito wrote: | How is Blade flying people between Manhattan and the | Hamptons? | | https://www.blade.com | merely-unlikely wrote: | The helipads are all on the rivers not inside Manhattan | ur-whale wrote: | Zero chance _in the US_ which - increasingly - is not the | center of the world. | JumpCrisscross wrote: | > _can't fly helicopters over SF or Manhattan_ | | Both cities have plenty of potential even with overland | banned. New York has a thriving helicopter business between | boroughs, up and down both sides of Long Island and to and | from the airports. The Bay Area isn't similarly knitted | together, but there is no good argument for not having an | electric hop from _e.g._ Mountain View to SFO. | woodruffw wrote: | Worth noting that the "thriving" helicopter business is | uniformly disliked by residents, due to noise pollution[1]. | | [1]: https://www.nydailynews.com/news/politics/new-york- | elections... | CoastalCoder wrote: | Can someone comment on why the parent would be (as of this | writing) downvoted? | | I'm wondering if there's some context I'm missing. | hef19898 wrote: | Best guess? Because the helicopter restrictions have | nothing to do with 9/11. | marcosdumay wrote: | The low energy density of batteries favors _large_ planes and | short distances. | | The only reason you are seeing them in small planes is that | electric propulsion makes VTOL viable, and VTOL favors small | planes. There is just this niche in aviation that can't be | filled at all by fossil fuel engines, so it's the first to | adopt electric ones. | | And yes, regulations will be the most important factor for | those. I imagine it all depends on how silent those planes can | be. But I doubt safety will be the limiting factor. | Deritio wrote: | Whenever I hear air taxi, I think about water bottles and | airport security. | | I don't want some rich dude flying over my house just because | he/she can afford to take a airtaxi from the airport to city | center while everyone else uses car or train. | | For other use cases they can do what they want. Australian | outback perhaps. | | But airspace pollution and a potential small airplane | crashing down in a city? No way. | inglor_cz wrote: | Air taxis are really useful in places divided by natural | obstacles. | | Hop over a fjord, hop over a mountain range. Much cheaper | and eco-friendly than building bridges and tunnels | everywhere, especially if the population density isn't | high. | idlehand wrote: | These kinds of places are also generally suitable for | hydropower and geothermal energy which gives considerable | amounts of cheap electricity. | [deleted] | p1mrx wrote: | > a potential small airplane crashing down in a city? No | way. | | Drones ought to have megaphones that scream DRONE CRASH | IMMINENT before impact. | jstummbillig wrote: | > No way. | | Wait until you see the motor carriages they claim are going | to replace horses one day. | tpxl wrote: | When a motor carriage loses power, it stops. When a | helicopter loses power, it kills people. | underdeserver wrote: | When a helicopter loses power it glides, safely, to the | ground - assuming it's being flown by a qualified pilot. | | https://en.m.wikipedia.org/wiki/Autorotation | kevin_thibedeau wrote: | That is a fantasy that almost never works out in real | life. Autorotation is only feasible with enough forward | air speed and control authority. Most helicopter crashes | happen outside that narrow zone of survivability. Even if | an autorotation is semi-pulled off it's likely to be a | hard landing that causes significant injuries. | sokoloff wrote: | Autorotations are regularly trained (and often taken all | the way to touchdown during training). The checkride for | private and commercial rotorcraft has a power failure at | hover taken all the way to touchdown as part of the | standard. | | Autorotations are by no means a "gimme", but if every | autorotation "likely" caused significant injuries, there | wouldn't be enough helicopters or pilots to go around (no | pun intended). | robonerd wrote: | > _That is a fantasy that almost never works out in real | life._ | | Can you quantify this? | | > _Most helicopter crashes happen outside that narrow | zone of survivability._ | | AFAIK the majority of helicopter crashes are not caused | by a loss of engine power, but autorotation is relevant | specifically in that context. It's not relevant to | helicopters crashing into hills during storms, or hitting | wires with the rotor, or anything like that. We're | discussing what happens if the engine stops, not all | accident scenarios. | | > _Even if an autorotation is semi-pulled off it 's | likely to be a hard landing that causes significant | injuries._ | | Yes, but it's better than being dead. | jackpeterfletch wrote: | I guess the question is - can we maintain the standard | that is 'qualified pilot' as it is today while making it | accessible enough for this to scale. | | Learning to drive and learning to fly isn't the same bar | today. | | And if Lilium think Palo Alto to San Francisco could be | $50, they're gonna need _alot_ of flights to balance | their costs. | jstummbillig wrote: | I think it's safe to assume this class of vehicles (and | likely any new class of vehicles from here on out) is not | designed to be piloted by a human past its prototype | stage. | gnulinux wrote: | You can recognize that cars are going nowhere and it's | best if we embrace this fact in our own ways (either by | being a car owner, or working around car-designed cities | the way we prefer), but still note that our cities could | have been designed better from scratch that doesn't favor | cars. Similarly, avoiding the same mistake now for | helicopters wouldn't be inconsistent with living with | cars. | jstummbillig wrote: | That seems reasonable, but what is missing (at least in | this branch of the debate) is data and counter arguments | that will not clearly peter out while the technology | matures, if they are even trying to be factual to begin | with. | | As an example, just on the topic of safety: Why would we | assume these machines are relatively dangerous once they | reach production? Just because they fly? I know of at | least one category of vehicles where on that basis our | intuition fails us to this day. | | And what happens when they do fail? They are not going to | explode randomly or purposefully target the closest | building. So what are the chances of all fail-safes | failing, and catastrophic outcomes occurring? | | Why would we assume whatever this technology eventually | enables will be operated by human pilots? I for one would | be fairly surprised if that was to happen at any | noteworthy scale. Clearly, the interesting part about | this prototype is electric flight, not its HID, agreed? | | So let's build cool things (electric flight is | potentially a cool thing) and then gather actual data | about other things it brings (some maybe not so cool), | before we "no way" it without any facts on the basis of | weak conjecture and personal feelings. | trompetenaccoun wrote: | The difference is we don't live in the sky. As long as | there isn't noise pollution (and electric planes are | supposedly a lot quieter), you have to try really hard to | create and issue here. Aviation is getting ever more | automated and safer. | thescriptkiddie wrote: | The motor carriage and its consequences have been a | disaster for the human race. | nostromo wrote: | They do this already. They're called helicopters. | staunch wrote: | > _They do this already. They 're called helicopters._ | | This is dangerously close to the infamous HN Dropbox | critique[1] :-D | | And it's likely wrong in the same way. | | 1. https://news.ycombinator.com/item?id=9224 | [deleted] | SideburnsOfDoom wrote: | Well, _electric_ helicopters or electric helicopter- | equivalent-vehicles would be a step forwards, correct? | ben_w wrote: | On the one hand, yes. | | On the other hand, making it cheap enough that mono- | millionaires can do it regularly is going to make a big | difference compared to the status quo. | wildmanx wrote: | > mono-millionaires | | Ah right, moving it from 0.1%-ers to 1%-ers is really | going to make a big difference. | jxf wrote: | Roughly 10% of Americans are millionaires, for reference | (though I doubt all of that is liquid). | edg-l wrote: | this comment reminded me of this | http://www.temporarilyembarrassedmillionaires.org/ | woodruffw wrote: | Sources online show that about 8% of Americans are | millionaires, with a significant bump during COVID | (probably because of the stock market.) About 10% of | households are. | | It's hard to find precise qualifications for how they | determine that, though. The households figure doesn't | include primary residence value (why?), and the | individual statistics don't mention liquidity. I suspect | that only a small percent of that 8% actually has $1+ | million liquid. | idlehand wrote: | Definitely not liquid cash, but assuming that a not | insignificant portion of those people are retirees or | planning to retire soonish (which is when net worth | peaks), I wouldn't be surprised if the percentage of | decently liquid assets like stocks and bonds are higher | than you might think. | brrrrrm wrote: | About 10x, right? | woodruffw wrote: | I don't know. The idea that a bunch of people with a | couple of millions of dollars in wealth can now zip | around above my house (and further alienate themselves | from civic reality, even more so than cars do) seems like | a pretty bad outcome. | ghastmaster wrote: | That is essentially how progress begins in every | industry. Wealthy people pay for new tech with their vast | fortunes, and many times, their lives. Once they work out | the kinks and economies of scale take over, the less | wealthy to enjoy the same tech at higher levels of safety | and lower prices. | vidarh wrote: | Helicopters are expensive to rent. If Lilium achieves | even 10x the cost they've suggested they can reach in the | past, they'll be attractive to a customer base who'd | never be able to afford regular helicopter rides. | prvit wrote: | > airspace pollution | | Bit of a fake concern, no? | | >potential small airplane crashing down in a city | | Is that really much worse than a SUV driving into a | building? | SideburnsOfDoom wrote: | > Is that really much worse than a SUV driving into a | building? | | Yes | SapporoChris wrote: | Think of it this way. If an SUV drives into your building | you can sue and make some money. But if some really rich | person crashes their flying gizmo into your building you | can sue and make a lot of money! | SideburnsOfDoom wrote: | So, are you saying that you think that the worst that | happens in car crashes is "someone could sue"? | | please don't waste our time. | woodruffw wrote: | I can't sue if I've been incinerated by an uncontrolled | lithium battery fire. | voldacar wrote: | Neither could you sue if you had been struck and killed | by an SUV. The end state of your reasoning is that nobody | can ever do anything that involves risk because someone | might die and be unable to sue. Sounds like an awful | world | woodruffw wrote: | Emphasis on "killed." I don't want to be struck by an | SUV, but one hitting my apartment at ordinary NYC | residential street speeds (at least, pre-COVID) is less | likely to kill me than a plane crash. | | Risk is a community exercise. You don't (or rather, | shouldn't) get to externalize _disproportionate_ risks | upon the commons because it makes your life easier. | | (An example of such a consideration: what happens when | the fire department shows up? They know how to deal with | a car accident; are they going to have the presence of | mind not to douse a vehicle that looks like a normal | personal aircraft in water?) | [deleted] | hef19898 wrote: | With more and more SUVs and truck beimg EVs that doesn't | change much. Well, eVTOLs will burn longer, not that it | matters because a large SUV will burn long enough to not | matter to _you_. | | And I'd bet a lot more on the crash safety of aerospace | cerrified batteries than those of the automotive sector. | closedloop129 wrote: | In that niche, why are batteries needed? Couldn't those | planes be constructed with gas turbines that generate the | necessary electricity? | t0mas88 wrote: | VTOL works fine with turbines, nearly all large helicopters | use turbine engines. They don't use the turbines as | generators but instead connect both engines to the rotor | via a gearbox. | marcosdumay wrote: | It's a matter of the weight/power relation. While batteries | suck on weight/energy, their weight/power is great. | | The lower that relation, the smaller you can make your VTOL | vehicles, and the smaller the vehicles, the cheapest and | more economical they are on total. | dr_dshiv wrote: | > I imagine it all depends on how silent those planes can be. | | I agree. I'd say, though, not just how silent, but how | pleasant sounding. Aesthetics of sound could make or break | this industry. | inb4_cancelled wrote: | You either get a chop-chop-chop, or a bzzzt, both | incredibly loud. It's not the engine that makes the noise, | it's mostly the propeller/rotor. The only advantage of | electric VTOLs is easier manufacturing and better control. | detritus wrote: | Props need feathers. | dr_dshiv wrote: | > You either get a chop-chop-chop, or a bzzzt | | Well, for instance, if they could line up the harmonics | to create a missing fundamental (eg with the addition of | external sounds), they could make propellers present an | artificially lower pitch. | Judgmentality wrote: | Your solution to them being too loud and annoying is to | make them louder and hopefully less annoying? | dr_dshiv wrote: | Yes. It's possible that louder but less annoying is more | viable, wouldn't you say? | vkou wrote: | I would say the most viable solution is to not subject | hundreds of thousands of people to an incredible amount | of noise pollution, so that a couple of playboys get to | skip a taxi ride to the airport. | | Private-transport helicopters or equivalents have no | place in cities. The gain is in no way worth the cost. | marcosdumay wrote: | There is plenty of space to change the number of | propellers, total area, and rotational velocity and | change the sound profile of the plane. | | There is also a lot of space on how you maneuver it on | the landing and take-out, so you make less sound when it | matters the most. | | There is the entire thing about minimizing weight too, | that also reduces sound, but it's also not clear how much | can be done. | | Overall, it's not clear at all how much noise the eVTOL | planes will make. | aliswe wrote: | do you have any references to back these statements up? I am | not an expert but I did read in a hacker News comment that | the energy density of gasoline is about 14 (reading that | article, its 50) times higher than a "normal" battery. | | if that is true (I do not think that he left references | either) then I would think that your statements seem less | plausible. | | a replier who later deleted their comment left a reference | saying the energy density is 50 to 1, comparing lithium-ion | battery to diesel: | https://www.batterypowertips.com/comparing-ev-battery-and- | fu... | [deleted] | kevin_thibedeau wrote: | Combustion aircraft also benefit from the weight reduction | as fuel is consumed. | swarnie wrote: | Did the Harrier just get skipped by the rest of the world? | | fossil fuel VTOL was cracked in the late 60s. | alluro2 wrote: | When talking about practical small plane with relatively | acceptable noise levels and fuel efficiency, I don't think | Harrier counts as it "being cracked". 125dB at 100 feet | from the plane, very limited time it can spend on vertical | takeoff while loaded, limited situations | (fuel/weight/thrust ratio) in which it can hover at | all...If it was cracked, the newer iteration of the "same | thing" - F-35B - wouldn't be so complex and take so many | billions to develop... | nradov wrote: | And the Harrier only barely worked at all. For most | operational missions, they couldn't really make true | vertical take-offs and landings. Instead they usually had | to make short ground rolls to get some lift from the | wings, or have a carrier ship sail into the wind. And the | mishap rate was appalling. | andrepd wrote: | https://www.youtube.com/watch?v=aH4b3sAs-l8 | cesarb wrote: | > The power density of even speculative near-future batteries | favors small airplanes and short flights. This doesn't really | mesh into the existing aviation industry, | | How short are these short flights? The hugely popular Ponte | Aerea (https://en.wikipedia.org/wiki/Ponte_A%C3%A9rea) has a | flight duration of one hour. | robonerd wrote: | That flight is about 230 miles (365 km) as the crow flies, | and they're doing it with 737s that seat 100+ each and fly | dozens of these flights a day. | | Compare that to this battery plane that can fly 200 miles: | https://cleantechnica.com/2020/01/29/rolls-royce-claims- | its-... | | These aren't in the same ballpark; they aren't even playing | the same game. If you want something to replace that plane | route, I suggest buying a lot of buses. | scythe wrote: | >[The electric airplane] doesn't really mesh into the existing | aviation industry | | The reason small electric planes haven't taken off [1] is that | they simply haven't proven their cost advantage. About one- | sixth of the cost of a flight is fuel, which can be difficult | to tax because of jurisdiction shopping. A third is labor, | including taking care of the plane. Seven percent goes to | building the plane. From: | | https://www.travelandleisure.com/airlines-airports/airfare-d... | | Optimistically, electric planes could be cheaper to fuel, build | _and_ maintain. That 's enough to upset an entrenched industry. | But it's not clear how it should be organized, and the | infrastructure mostly doesn't exist. Plus, the scale you expect | to operate at depends on battery technology, which has been a | little up in the air [2], and you don't want to design your | operations around 1000-mile ranges if it's going to be 2000 in | ten years. | | 1: Sorry. | | 2: Sorry. But see: | https://www.nature.com/articles/s42004-022-00626-2 | ur-whale wrote: | There's other aspect than the pure economic aspect: | | Noise | | VTOL | | When both are combined, this makes Urban flight closer to | feasable. | dzhiurgis wrote: | Dropbox vs rsync moment right here | bozhark wrote: | Air taxi is their market | momenti wrote: | Lilium's plane has 30 engines, multiple independent battery | packs, and electric motors are way more reliable than jet | engines (due to being so much simpler). A Lilium plane may have | a 1000x higher chance of a crash in case of full engine | failure, but perhaps that can be compensated for by 1000x times | simpler/redundant propulsion technology. This seems to be very | hard to assess in theory, so we probably just have to wait and | see how it performs in practice. | vidarh wrote: | At some point at least their design also included a whole | plane parachute. I don't know if that's still the case. | SoftTalker wrote: | 30 engines = 30x the chance that at least one will fail. | Maybe one is tolerable. How many can it lose and still fly? | leoedin wrote: | That's all very well, as long as there's no common modes of | failure. Redundancy can be a means to achieve reliability, | but not always. Imagine the cause of failure is a bug which | kicks in at a specific time of day, or an integer overflow | which happens after a certain amount of uptime, or all the | motor drivers are susceptible to a specific RF frequency. It | doesn't matter how many motors you have if they're all | susceptible to the same failure mode. | mbreese wrote: | _> integer overflow which happens after a certain amount of | uptime_ | | It's not just electric powered planes that have to worry | about such things... this was an issue for the Boeing 777 | Dreamliner too. If it was powered on for longer than 248 | days, it could lose all electrical power due to an overflow | in the generator. | | https://www.engadget.com/2015-05-01-boeing-787-dreamliner- | so... | | I'm not saying it isn't a concern, but rather it is a | concern for all planes (and vehicles for that matter). Many | commercial passenger planes are now fly by wire. If you | lose electrical power, you'll also lose control. So, while | we're talking about purely electric planes, the problems | are universal. | hef19898 wrote: | That's what certification is there for, isn't it? | ben_w wrote: | I can't possibly comment on any specific design, but what I'd | _like_ is something that can replace road ambulances. | | This is partly because I live right next to a busy crossroads | and often get multiple _simultaneous_ sirens; but I do also | wonder how faster they can arrive by going as the crow flies | rather than following street layouts, and how much they have to | slow down both for traffic and for blind corners. | dzhiurgis wrote: | I keep thinking remotely controlled cargo operations, | especially around bad terrain and difficult water features. | Great for proving design and catching bugs for initial years. | jlmorton wrote: | This is one of the primary reasons I've bought into the eVTOL | revolution. I'm also skeptical about these filling city | skies, due to safety, noise pollution, etc. But the market | for emergency and special purpose vehicles alone is enormous. | | The US market size for existing _air_ ambulances is itself | $4.5 billion dollars annually. The market size for standard | ambulances is nearly 10x that. | | When you expand this to the rest of the world, you can easily | see a 100+ billion market for these sorts of vehicles, | whether in ambulance services, firefighting, agricultural, or | any number of other activities. | | It's still possible we develop near-to-city eVTOL airport | systems for short distance travel. But even absent that, I | still think there's a big market opportunity. | SoftTalker wrote: | For critical patients helicopters are already used. For | patients who need to get to a hospital but are short-term in | stable condition, is the extra expense of an air ambulance | justified, in a health care system that is already | unaffordable? | clouddrover wrote: | > _The power density of even speculative near-future batteries | favors small airplanes and short flights._ | | Use a hydrogen fuel cell instead: | | https://www.bbc.com/future/article/20210401-the-worlds-first... | | https://www.aircargoweek.com/zeroavia-and-monte-strike-deal-... | | https://www.flyingmag.com/joby-secretly-bought-a-hydrogen-el... | | https://interestingengineering.com/german-firm-record-altitu... | mLuby wrote: | I love that tell-tales are still part of vessels thousands of | years later. | [deleted] | rklaehn wrote: | This is a major milestone for them. Very nice to see the | indicators suddenly transitioning to laminar flow. | | It is a shame that they only stayed in this flight regime for a | few seconds, but they will now gradually expand the envelope. | | Here is a good article explaining the tradeoffs they make vs. | more traditional VTOL craft with larger propellers: | https://ir.lilium.com/news-releases/news-release-details/tec... . | TLDR: they accept more inefficient performance during hover | because they won't stay in this flight regime for long. | beefman wrote: | Transportation economics are dominated by the passengers per | pilot ratio. Small vehicles aren't economic unless they are | piloted by a passenger or an AI. | | AI piloting should be easier with aircraft than cars. | drexlspivey wrote: | Fuel costs are in the order of hundreds of thousands of dollars | per flight. Surely that's much more expensive than the pilot | costs? | redleader55 wrote: | According to [1] fuel costs are in the tens of thousands for | intercontinental flights. Pilot training is around 200k USD | [2] and thousands of hours to be accepted to fly reputable | companies' planes. I wouldn't call pilot costs negligible. | | [1] - | https://www.google.com/amp/s/simpleflying.com/commercial- | air... | | [2] - https://fly-ga.co.uk/how-much-cost-become-pilot-learn- | fly/ | hef19898 wrote: | We are living in a world were co-pilots sometimes pay to be | allow?d to fly in order to get flight hours in towards type | ratings and promotions. Initial pilot trainig through | airlines, and paid by those with almost guaranteed | employment afterwards, is a thing of the past. Most pilots | pay for their own training now. Ehich leaves salaries, | which are indeed negligable. | | Even if you accoubt for training costs, those are | negiligable whem compared to fuel, maintenance,... | beefman wrote: | For commercial jetliners? Yes, but they have a very high | passenger:pilot ratio already. | | Also, the order is tens of thousands (for a typical | transatlantic flight). | | Across transportation modalities, fuel costs are usually a | minor contributor to total cost. For a commercial airline | flight, about 10% of ticket price. | | See also, this comment of mine on a recent story about the | Joby eVTOL: https://news.ycombinator.com/item?id=29705650 | a-dub wrote: | i don't know what the proper term is, so i'm just going to make | bjork happy and call them aerodynamic scientifical tassles. | | are they just recorded visually by a camera and then inspected | manually for a test flight or are they part of some kind of | active sensor system. | | cool stuff. | carabiner wrote: | Tufts and they are recorded on video. | [deleted] | cousin_it wrote: | I think the ideal personal aircraft would work like a quadcopter | during takeoff and landing, but unfold wings for cruising flight | with much better efficiency. It seems there's already such a | drone called Transwing, I hope they make a personal aircraft like | that. | cvccvroomvroom wrote: | Not really a plane so much as a expense, semi-hovering, large | drone, inefficient consumer of electricity. | | An efficient vehicle would have significant aerodynamic | properties like a glider. Instead, it's mostly pushing itself up | rather than using an airfoil. | | Also, in terms of climate change, widespread use of anything | similar would be devastating for the environment as it's an | inherently extremely uneconomical mode of transportation. | | If we wanted better transportation for less energy, it look like | a train. | staunch wrote: | Pretty exciting. I consider this a real proof of concept for | shuttlepods AKA flying cars. I'm sure there's a lot of work left | to do this shows how much is already possible with _relatively_ | little effort by a _relatively_ small company. | | Seems like there's a few advances that should enable it to | finally happen: | | Automated: so there's no pilot to make mistakes and drive up | costs. Automated flying is easier than navigating streets, so | this is probably already doable at scale even though self-driving | cars are taking longer than hoped. | | Electric: so the at-scale/long-term cost per flight can be nearly | zero. Seems possible something like this could be manufactured | for $100k at scale and fly (with maintenance) for multiple years. | | Multi-rotor w/efficient DC motors, multi-battery pack w/advanced | batteries, and multi-computer w/advanced processors: so there's | no single point of failure and lots of opportunity to recover | from failure, and to enable easy VTOL without runways. | | The Wright brothers would love it. Their initial vision was to | not need specially built runways or airports. It turns out that | was "too early" of an idea to be practical but we're getting | close. | | An "infinite highway of the air" (Wilbur Wright) is an exciting | goal. | amelius wrote: | Why does this look like it's entirely CGI? | AustinDev wrote: | Resolution and framerate. What were you watching the video in? | Zak wrote: | I am (perhaps unreasonably) annoyed by the mixed units. The | narrator and captions are using knots for speed, which is | standard for aviation in most of the world. The on-screen display | is using km/h, which is standard for everything else in most of | the world. | 369548684892826 wrote: | And ft/s for vertical speed. Really got a bit of everything | going on there! | aero-glide2 wrote: | That is standard for vertical speed everywhere | bernulli wrote: | That's funny for someone with aero-glide2 as user name. I'm | used to metric variometers in gliders. | chipsa wrote: | And yet, excepting two countries (IIRC), altitude is | normally in feet for ATC. Which means instruments are in | feet. | throwaway019254 wrote: | It has vertical take off? It must burn so much electricity for | that? | | Wouldn't be classic horizontal take off more efficient? | mrfusion wrote: | I was actually just thinking that VTOL aircraft could solve the | housing crisis considering we're using 1000s of acres of prime | real estate in every city for airports. Anyone want to flesh out | that idea and write it up? | | (I'd be curious if anyone could correct my thinking instead of | downvoting) | TulliusCicero wrote: | There's no way airports use enough land to be able to 'solve | the housing crisis' by using it for housing. | | The housing crisis is an entirely self-created problem by the | societies it exists in, and it has little to do with amount of | land. For example, Japan and South Korea have relative little | land -- and in the case of Japan, very little non-mountainous | land -- relative to their population, and yet rent prices there | are quite affordable, even in the megacities of Tokyo and | Seoul. | | Western cities tend to have some combination of greater | restrictions on density/housing forms, and harder/more | ambiguous red tape to develop new buildings. Relaxing these | regulations would at least alleviate, it not outright solve the | crisis, but people just don't wanna do that. It's not a | technical issue, it's just that the political will isn't there. | | As an example of ambiguous red tape, take the ubiquitous | "community meetings" that are common in US cities any time | there's a major new development. It's common for neighbors to | raise random objections that may or may not relate to any | building codes or zoning regulations, and then a planning board | to force the developer to adapt to those objections, or just | block the project outright. | | What this means, is that there's really two sets of laws: one | on the books, that was developed through normal democratic | processes like city council members voting on them, or local | initiatives passing, and then the second set is whatever the | local residents feel like accepting in their heads. | | We would never accept this for other laws, the idea of, "well | sure you didn't break any laws on paper, but local residents | don't like what you did and a few raised a stink about it at a | community meeting, so you're going to jail anyway." But that's | how building permitting actually works. You can't just follow | actual laws, you have to make the subset of people who show up | to community meetings all happy. | hrgiger wrote: | I didnt downvote, I think those VTOLs also at the end gonna | land somewhere, its reminds me this pic [1]. | | https://www.google.com/search?q=1+bus+vs+related+cars&newwin... | jillesvangurp wrote: | They can land on roofs, in parks, any open area large enough | basically. | | That kind of is the whole point being able to land anywhere. | Short term, anything that already accommodates helicopters | would be good enough. The problem with those is mainly that | helicopters are very noisy so people don't like to have | helipads everywhere. | | But considering, these VTOL planes tend to be a lot less | noisy, having them land in more places might end up being | less controversial. | | Either way, it would be a perfectly valid way to commute | 50-80 miles in ten minutes or so and skip the 2 hour car | ride. I could see that become a popular thing. Initially | probably quite expensive but the pitch for these devices | seems to be that they could be mass produced cheaply. | hrgiger wrote: | Yes my answer was for the airport, I definitely would like | to see them around and try it! | jltsiren wrote: | Any powered aircraft large enough to carry a person is | inherently noisy and dangerous. All serious vertiport | proposals I have seen for quiet electric aircraft assume a | dedicated facility at least as large as a city block. And | even those are only feasible if there is no significant | NIMBYism in the area. | | Rooftop landing pads could work, at least in principle. | They are however risky enough that Western cities often | outright ban them in urban areas or limit their use to | emergency situations. | mrfusion wrote: | That's true but runways are quite long and we need several of | them at least. | | And we wouldn't need the same level of centralization for | small landing pads. | ncmncm wrote: | No city will be scrapping its runways. Period. So if you | add VTOL pads that takes more of high value real estate. | andbberger wrote: | the hover power density is insane, 2500W/kg | ur-whale wrote: | Oh, wow, that is intense indeed. Where did you get these | numbers? Was it in the vid? | m00dy wrote: | and again, we see an amazing german engineering. | [deleted] | carabiner wrote: | Making a comment to represent all aerospace professionals getting | major gell-man amnesia vibes from this thread. | xeromal wrote: | Is hydrogen gas dense enough to power an aircraft? I don't think | battery technology will be dense enough to power aircraft in our | lifetimes, but I feel like hydrogen could play a part | NegativeLatency wrote: | https://en.wikipedia.org/wiki/Lockheed_CL-400_Suntan | jillesvangurp wrote: | There are a few flying prototypes of various sizes, so clearly | there's a big flaw in your argument. | | In principle you can burn hydrogen in a jet or even in an | internal combustion engine. Both have already been shown to | work. Fuel cells are another possibility of course. As far as I | understand it, most plane manufacturers are already designing | planes with hyrdogen as a power source. Particularly for big | Jets, the consensus seems to be that that is happening. | | The main challenge in the market is similar with what we've | seen with existing car manufacturers. Changing technology | disrupts them and threatens their profitability. So, you see | companies that are talking the talk but not really committing | to much beyond that. E.g. Airbus and Boeing have lots of fancy | concept planes but not much in the line of actual planes being | designed and marketed yet. | | As for battery, there are several battery powered planes flying | and certified (or in the process of being certified). Most of | the companies behind those are following up with longer range | versions that they've already announced. | | Maybe aviation fuel goes a bit further but it is very | expensive. Especially for general aviation, the value | proposition might look pretty good a few years down the line | with better ranges and charging speeds and lower cost. That | does not even require that much in terms of breakthroughs in | energy density either. Anything certified today is using | battery tech that is several years old and was probably picked | conservatively to speed up the process. That's just the nature | of the certification process. What's flying legally today was | the state of the art about half a decade ago in terms of | batteries. Probably not that impressive compared to the latest | electrical cars. | ggreer wrote: | Hydrogen looks good on paper but has a lot of practical issues. | | - Currently, the most economically efficient method to obtain | hydrogen is by methane steam reforming. This releases a lot of | CO2. | | - If you want to get hydrogen without making CO2, you'll need | to use electricity to split water. That's around 60-70% | efficient. If you used the same electricity to charge a | battery, it would be over 90% efficient. | | - Hydrogen embrittlement is a problem for tanks and pipes. This | means you can't easily repurpose natural gas infrastructure. | | - Hydrogen has no odor, and adding an odorant can foul fuel | cells. The most effective solution is to add hydrogen sensors | everywhere, increasing costs. | | - Hydrogen burns with an invisible flame. It's also much more | easily ignited than gasoline and will burn in a wider range of | concentrations. (Though unlike gasoline, it won't pool up.) | | - Hydrogen is a small enough molecule that it will slowly | permeate through a sealed tank. Newer tanks have coatings that | reduce this, but research is ongoing. | | - Remember the ideal gas law? The pressure change involved in | refilling a hydrogen tank causes the nozzle to get very cold. | Even in southern California this can freeze the nozzle to the | tank, limiting refill speeds. | | - Hydrogen is light, but tanks are heavy. The Toyota Mirai's | tanks weigh 87.5kg but can only store 5kg of hydrogen. | | Considering all of these disadvantages, I don't think hydrogen | aircraft are going to happen. | p_l wrote: | Hydrogen has been tested, including in Soviet Union which | considered it the future fuel for airliners, tested on Tu-154M | modified for cryogenic hydrogen fuel. | panick21_ wrote: | Lithium Battery are already enough to power some airplanes. | Airplanes now in development using current battery tech are | already targeting many niches. | | They will not fly across oceans for a while but a lot of | aviation is limited to one continent. | | And beyond that, the cheaper operational cost, can change how | flights routes significantly and even open more markets. | | The problem with airplanes is partly that it takes a very long | time to design a new one and the cost are significant. To | create a longer range electric plane, you need to really start | from the ground up, and rethink the airplane. Even with cars | this took 10-15 years. For planes it will be even more | difficult. | stareatgoats wrote: | Agree: https://newatlas.com/aircraft/hypoint-gtl-lightweight- | liquid... | skykooler wrote: | Hydrogen has an excellent energy-to-weight ratio, but in terms | of energy-to-volume it's even worse than lithium-ion batteries | as a gas. This is why proposals for hydrogen airliners usually | need a complicated cryogenic setup to store it as liquid | hydrogen instead. | ncmncm wrote: | You don't need a "complicated" cryogenic setup. You just need | insulated tankage. But it won't fit in the wings, so you need | new airframes or fuel nacelles. | | We have a very great deal of experience with fuel nacelles | already, because that is what a "drop tank" looks like; you | just omit the "drop" complication. The advantages over | inboard tankage are safety, possible retrofitting of existing | fleets, and short plumbing runs. | | Once LH2 aircraft are used on any route, kerosene craft will | be wholly unable to compete, even without carbon taxes. | Carbon taxes could be spent on accelerating the transition. | hgomersall wrote: | Or a radically different airframe design. One that perhaps | is much bigger and flies slower but is very low weight (by | virtue of being mostly full of hydrogen). | ncmncm wrote: | A different airframe design would take a long time to | field, and with inboard tankage arguably less safe. | Kerrick wrote: | There is already a type-certified electric aircraft. | https://www.pipistrel-aircraft.com/aircraft/electric-flight/... | marcosdumay wrote: | Hydrogen looks like the perfect storage medium for aviation, | except that every way people created to store it is either very | dangerous or reduces its energy density enough that it becomes | similar to batteries. | runlevel1 wrote: | Having motors along the whole trailing edge of the wing surely | kills the glide ratio of this, right? | | Losing power on one side seems like an even more frightening | prospect. Even if the motors were somehow allowed to freely | windmill, that's a lot of surface area for drag. | | At the very least, it must have some unusual aerodynamic | properties. | melony wrote: | Why is the airflow so turbulent over the trailing edge? Is it | even considered a full transition? | rklaehn wrote: | > Having motors along the whole trailing edge of the wing | surely kills the glide ratio of this, right? | | The motors are running at reduced thrust and changed geometry | during all parts of the flight. | | Regarding power loss: Last time I read about it in more detail, | the impellers were organised in groups of 3, and you could lose | one such module anywhere on the plane, even on the front | canards, without issues. On the wings you could probably lose | several. | | If you lose all electricity everywhere that would be a bad day, | but the same is true for a modern airliner with fly by wire | controls. | nradov wrote: | Modern airliners are equipped with ram air turbines to | provide electrical power for critical systems even if they | lose all engines and the APU. | fmakunbound wrote: | Recently read unleaded aviation fuel seems to be an | insurmountable problem for the FAA. Will it be that hard with | electric aircraft or is it further along? | p_l wrote: | Completely unrelated. | | The issue with unleaded fuel is that the goal is to make it a | drop-in replacement on all engines that currently use | AVGAS100LL, which is the only remaining leaded fuel in large | use (a lot of small planes can actually fly on unleaded | aviation fuels and there are some available, it's just 100LL is | "default" fuel when thinking of piston engines). So they have | to certify that if you swap the fuel, preferably without any | modifications, then it's safe to fly. | | Battery powered aircraft go through normal certification | process for a new design. | akrymski wrote: | 1. We already have VTOLs - helicopters. How do the economics of | this compares to helicopters? | | 2. Surely hydrogen is a better fuel source for VTOL? | sigmoid10 wrote: | 1. Helicopters are technically VTOL, but what you'd really want | is something that can transition between vertical takeoff and | horizontal flight using conventional wings, which is much more | efficient and stable when travelling from A to B. | | 2. VTOL requires engines which provide very high thrust and | very short response time during vertical ascent. This is | incredibly hard to do using combustion engines - which includes | hydrogen - but trivial using electric engines, which is why | every cheap drone can easily fly using only vertically mounted | propellers. | robonerd wrote: | > _VTOL requires engines which provide very high thrust and | very short response time during vertical ascent_ | | Not necessarily. That's how you do it with electric | multirotors, because it's simple and electric motors are good | at it. With turbine powered VTOLs, the rotor blades are | actuated to change their angle of attack, and consequently | how much lift they're producing, using swashplates and cyclic | controls. That's what traditional helicopters do, and what | tiltrotors like the V-22 do too. | | Incidentally I think tiltrotors are what you're describing as | the VTOL ideal; they take off like helicopters then | transition into horizontal flight using conventional (albeit | stubby) wings. They're not exactly a runaway success and have | had a rocky history, but they do work. | reacharavindh wrote: | This has been one of my "shower thoughts".. | | If jet fuel is very efficient and dense for the more demanding | take off and low altitude legs of the flight, we aren't there | concepts that do a hybrid of jet fuel and electric powered | flights that use the electric propellers only where they are | efficient, leaving the existing system for the more challenging | tasks like take off? | ramesh31 wrote: | Same problem as all hybrid power systems; weight and | complexity. You can't get away with generalist designs in an | aircraft the way you can with a land or water vehicle. Carrying | around the weight and drag penalties of an unused engine would | more than detract from any efficiency gain with an electric | auxiliary. | Ekaros wrote: | Also unlike with sea where efficiency gains from hybrids out | gain the mass and volume losses, same doesn't apply to air. | | Also, some of the engine types like turboprops are pretty | good already. And hybrid systems likely won't make gains and | probably even lose quite a bit. | krallja wrote: | Then you have two different energy storage areas plus two | different drive trains, and the associated weight gain that | implies. Hybrid road vehicles make it work because they have | the weight supported by the ground, plus the additional benefit | of regenerative braking, which evens out energy usage in stop- | and-go and hilly travel. Planes don't work at all in either | scenario. | cjbprime wrote: | There are some electric gliders which at least use the same | intuition -- you need a ride for takeoff, but then there's an | electric sustaining motor for once you're in the air (and don't | have lift). | rwmj wrote: | Or can you have a 100' long cable to directly power the lift | off and first hundred feet of the flight? (For a conventional | runway takeoff, some kind of powered tracks.) | amluto wrote: | Aircraft carriers effectively have powered tracks. As I | understand it, this is currently quite dangerous and | expensive. | akira2501 wrote: | Because we use the engines to generate hydraulic power and | electric power, and on larger planes it drives the air | conditioning. The engines do a lot more than just provide | thrust. | p_l wrote: | In addition to other comments here about increased weight and | complexity... | | There's an area where it makes sense, and it's being trialed in | few places. Namely electric propulsion for taxiing. | | You see, Taxiing on jet engines is very, very, very inefficient | - you stay pretty much in worst fuel economy all the time to | the point that taxiing burns more fuel than few hundred | kilometers of cruise on the heaviest airliners. In fact | optimizing taxiing is important enough that landings are | calculated to ensure you have shorter distance and can reuse | kinetic energy from landing, and depending on plane it might be | norm to shut off all engines except one during taxi. | | So there's experimentation with either adding electric | drivetrain to main gear or having remote-controlled pulling car | or quick-detachable (and also remote controlled) drive blocks | that could attach to main gear. This way the plane would only | start the engines just before going onto its designated runway. | dwighttk wrote: | I am not an expert | | This doesn't seem to make any sense to me. If taxiing is so | inefficient, why not use the pushback carts to push/pull the | planes into position? | | I've been to many more airports that make the plane taxi for | quite a distance, like 20 minutes (not just sitting and | waiting, but moving) to get to the gate than ones that | "ensure you have shorter distance and can reuse kinetic | energy from landing" | p_l wrote: | That's essentially what the prototype projects are doing, | except optimized for taxiing vs. "just" pushback or | maintenance moves - normal pushback truck is not exactly | prepared to handle high traffic taxiing, partially due to | how communication between aircraft and pushback is handled. | | So those projects investigate a solution that is optimized | for the whole taxi trip at full traffic at the airport, | including electric solutions to avoid currently heavy | diesel pushback trucks. | SV_BubbleTime wrote: | This all just furthers my idea that if I'm ever a time | traveler, I'll try and convince the past to make airplanes | that all have aircraft carrier sling shot systems... for fun. | stavros wrote: | Taxiing is the process of getting the plane to the | slingshot. | simonsarris wrote: | Yeah, you'd need to convince the past that "tugboats but | for aircraft" is a good thing to standardize. | baybal2 wrote: | Lilium is a shady company | | First, it's people without even most basic aeronautic backround | designing an aircraft. | | Second, the number of flaws with their scheme being pointed by | experts is so huge they cannot possibly get certified without | throwing out everything, and redesigning completely from scratch. | | Third, they finally hired somebody with the background, but so | far nobody seen any change from "submarine ramen startup," to a | serious company happening. Unlike with SpaceX, where Elon | promptly yielded to professional engineers shutting down his | fantasies like an SSTO design, 3D printing the whole rocket, or | developing an ion engine to replace chemical one for last stages. | | Fourth, they lash out on all criticism with "you have no vision," | it's "aircraft 2.0," and similar dismissal. | | Fifth, they courted investors with physically unachievable | performance figures. | | To me it's very clear, the company is heading the way of "HTML | supercomputer" | | P.S. Speak of the devil, it's already starting: | https://www.bloomberg.com/press-releases/2022-06-02/lilium-i... | heisenbit wrote: | They have 600 people, onboarding a veteran Airbus exec as CEO | and are located in the south of Germany which is the center of | the German aircraft and high tech manufacturing industry. On | the surface they pass my smell test. | | From their website: > As Co-founder and VP Product, Patrick | leads the global digital and physical product strategy owning | the technical operation readiness of the aircraft and its | mobility service . He holds a PhD in Aerospace Engineering from | the Technical University of Munich. | | Claiming they have no clue seems to be without facts. | bouchard wrote: | Their website isn't exactly up to date. | | Dr. Patrick Nathen who published Lilium's white paper | detailing their aircraft architecture has left his VP role | and is now an engineer within their flight mechanics team | [0]. | | [0] https://www.linkedin.com/posts/dr-patrick- | nathen-1a0840b3_en... | baybal2 wrote: | snek_case wrote: | I'm also highly skeptical. I've heard from someone in the | industry that their original demos were intentionally | misleading. They had images of the Lilium aircraft taking off | and flying for a bit, but what they didn't tell you was that | the thing that was flying was essentially a large foam model | that probably weighed 1/10th of what the real thing would. I | don't know if that's the case anymore, but I wouldn't | personally invest my own money in them though. Joby seems like | they have a much more promising electric aircraft. | | I don't have a position in either company nor in any electric | aircraft stocks. | hrgiger wrote: | That law firm looks like quite active on stock market [1]. | There are like hundreds of them I saw on the news. | | [1] | https://www.globenewswire.com/en/search/organization/Portnoy... | panick21_ wrote: | > Unlike with SpaceX, where Elon promptly yielded to | professional engineers shutting down his fantasies like an SSTO | design, 3D printing the whole rocket, or developing an ion | engine to replace chemical one for last stages. | | What's the source for that? ___________________________________________________________________ (page generated 2022-06-12 23:00 UTC)