Lilium Runs Out of Money

Giant swinging rotor blades of death. Helo crashes can go very wrong. Electric power allows multiple smaller rotors housed in protective fairings.
I could be wrong, but I suspect as these things get more hours on them we will see that they are even less safe.
 
What truck are you filling up for $35?
Gas is than $3/gal. A few days ago it was $2.44 locally. I drive all week and to fill it up costs $30-$35. 2014 Caravan gets 30+mpg highway.

When I lived in the mountains this definitely not the case, but in the flatness of the SE mpg has been great.
 
Unless they have figured out rapid charging, more capable batteries, and/or battery swapping, won't the eVTOL's be limited to a handful of trips in the morning and another surge in the evening ('cause they need a 4 hour charge between their hour long duty cycle)?
All the eVTOL battery systems I've seen or read about support fast charging at non-standard rates. However, it really depends on the OEM how this is handled. For example, Joby produces their own batteries in-house and they have a high energy density. Where Archer gets theirs from a 3rd party. What it boils down to is how they will be operated which will determine the battery drain vs charge.

I believe a standard use/charge scenario will be a 25 mile flight with a 10 minute fast-charge between flights for the day. And in high volume routes they will be operated in packs where the odd aircraft will be cycled out for a longer charge period. But without a certified aircraft flying a certified route this won't be 100% known till then.

But if the industry continues to move toward hybrid power sources with a turbo-generator/battery combo, then you basically have an "unlimited" power source for an average operational time period. Honda and Safran have been the big drivers in this direction. The technology in this area has been very fluid.

I could be wrong, but I suspect as these things get more hours on them we will see that they are even less safe.
This will be the most interesting part to watch. I believe these eVTOLs will be the 1st aircraft type certified under performance based rules where the majority of failure probabilities will have to be demonstrated. And as mentioned earlier, the ability to make just about every system on a eVTOL redundant in some fashion makes any potential future failure a non-issue.
 
I liken this urban air mobility scheme as an Uber of the skies (Uber actually invested 75m in Joby). Except Joby claims their evtol will cost 1.3m. that seems extraordinarily optimistic considering what an sr22 goes for. Uber doesn't have to pay for a car, or the development of a car. And yet Uber has managed to hemorrhage 31 billion since 2014, only being profitable 2 of those years.
 
Assuming the battery tech makes leaps and bounds to make a viable power to weight ratio to comply viably with the realities of nature (big if), what about down wash? Helicopters are bad enough with comparably low disc loading compared to these multiple rotor systems, basic physics mandate that by moving a lower mass of air it must do so at a higher velocity to get the same amount of lift, so how are the pedestrians/neighbors, insurance agents for the cars parked around where one of these land going to react when it starts sand blasting everything within a large radius on its take off and landing site with all the dust, pebbles, sticks, leaves, what have you?
 
Unless they have figured out rapid charging, more capable batteries, and/or battery swapping, won't the eVTOL's be limited to a handful of trips in the morning and another surge in the evening ('cause they need a 4 hour charge between their hour long duty cycle)? They absolutely have to figure something out there, because it'll be ridiculously expensive if an expensive asset can only operate 2-3-4 hours a day.
There's not much to figure out there. There are tons of fast chargers out there for ground-pounding EVs, and there was a recent thread showing one of the EA? (aircraft) manufacturers had already been putting in fast chargers at airports. I would expect they'll also work it so that the "vertiports" have lots of fast-charging plugs that will go in immediately upon landing, be plugged in for the duration of pax loading/unloading or waiting for the next trip to call, and then be unplugged immediately before takeoff... Or potentially even be designed to unplug upon takeoff so they could even get a bit of extra juice for the initial lift where power consumption will be highest.
I liken this urban air mobility scheme as an Uber of the skies (Uber actually invested 75m in Joby). Except Joby claims their evtol will cost 1.3m. that seems extraordinarily optimistic considering what an sr22 goes for. Uber doesn't have to pay for a car, or the development of a car. And yet Uber has managed to hemorrhage 31 billion since 2014, only being profitable 2 of those years.
That's probably because Uber has been spending tons of money trying to get rid of their largest expense: Drivers.
 
Manhattan to JFK shuttle

3 batteries, one eVTOL's.

Takes off from Manhattan, flies to JFK using battery 1, unloads passengers as the automatic tug runs under the plane, releases the battery, lowers it, and backs out.

Second tug runs under, raises and latches battery 2 in, backs out, New passengers are loaded, and battery 1 is on fast charge.

Flies to Manhattan, unloads passengers as the automatic tug removes the battery, second tug runs in, and attaches 3rd battery, passenger exchange is completed, and flight to JFK is started. Battery 2 is on fast charge.

At JFK, battery one is charged, replaces battery 3, and the plane returns to Manhattan, passengers and battery are changed, 1 replacing 3, and back to JFK


Thus, with quick connect batteries with smart tugs exchanging them, 3 batteries would sustain an eVTOL for continuous round trips from downtown to JFK and return, all day.

Charging time is the time required to unload all passengers and luggage at two ends, plus round trip flying time.

Obviously, the chargers would be engineered to exactly match the batteries, and the batteries exactly matched to the requirements for the one way trips. This also assumes the chargers are the property of the shuttle service, there is no wait in line time.


Tight scheduling would be done by computer reservations, and flexible pricing to maximize income at peak times. Smarter users would plan and reserve further in advance, and avoid peak pricing, but risk cancelation fees.

Long range batteries are not essential for such shuttle service.
 
But darn good connections would be. I’ve been around enough electric forklifts using the same type of scheme and the connector plugs to the batteries don’t last long.
 
But darn good connections would be. I’ve been around enough electric forklifts using the same type of scheme and the connector plugs to the batteries don’t last long.
A hybrid fast-charge/swap system could also be used, depending on the capacity and range needs. Start with the battery at 100%, burn 20% per trip and charge 10% per trip while swapping pax, and when the battery is down lower than 30% for example, it gets swapped and fully charged.

I would imagine that the swapping wouldn't really be needed, though, as there's likely going to be a morning push, and evening push, and enough time in between for aircraft to rest long enough to get a full charge on a fast charger in between.

I think the industry is going to learn a lot about how people actually use these things in the first few years, and the second generation aircraft will be much more suited to the mission(s) that are most popular than the first generation.
 
The EVTOL pushers say you don't need to go as far as fast as you used to in ICE vehicles. I told a guy once my IO360 and 72 gallons of fuel allow me to fly for 6 hours at 135kts. He told me "yeah but you don't need to". Huh? All to convince me 45 minutes on a battery at slower speeds was the future.
 
Assuming the battery tech makes leaps and bounds to make a viable power to weight ratio to comply viably with the realities of nature (big if),
Current eVTOL battery tech (Wh/kg) is already sufficient to handle the required performance and certification requirements. But have read where some 3rd party battery OEMs working on Gen 2 battery cells that will double the current Wh/kg capacity.

what about down wash?
The FAA has issued interim guidance on the construction and use of vertiports/vertistops. Similar to heliport guidance, this document will regulate the requirements to protect items from downwash damage during operations.

A hybrid fast-charge/swap system could also be used, depending on the capacity and range needs.
I believe Joby uses a pair of fast-charge receptacles which allow 2 battery packs to be charged simultaneously.

I think the industry is going to learn a lot about how people actually use these things in the first few years, and the second generation aircraft will be much more suited to the mission(s) that are most popular than the first generation.
^^^^ This. Most UAM plans have a 4-tier implementation schedule as the system matures. Gen 2 versions are already on the table. I had heard it being compared to flat screen TV evolution: 15 years ago you couldn’t by a 75” flat screen for less than $100k, now they're available in Walmart for $500. The scalability of electric propulsion or hybrid-propulsion when compared to conventional methods is mind-blowing. Never thought I'd see it get to this point so fast.
 
I believe a standard use/charge scenario will be a 25 mile flight with a 10 minute fast-charge between flights for the day.
Without doing the math, replacing the energy used in a 25 mile flight in a loaded eVTOL in just 10 minutes sounds like it would require a ferocious charge rate.
 
Without doing the math, replacing the energy used in a 25 mile flight in a loaded eVTOL in just 10 minutes sounds like it would require a ferocious charge rate.
astronomical
 
sounds like it would require a ferocious charge rate.
I seem to recall 5C or better charge rates but don't know for sure as it wasn't something I followed. But I know they charge all 4 Joby battery packs at the same time and the charger cord has built in coolant hoses that connect to the aircraft coolant system to maintain battery temps during charging!
 
Without doing the math, replacing the energy used in a 25 mile flight in a loaded eVTOL in just 10 minutes sounds like it would require a ferocious charge rate.

I'll try on the math.

Mass of aircraft: 1000kg
VTOL ascent to 500m (potential energy = m * g * h): 1000kg * 9.8m/s^2 * 500m = 4.91MJ
Forward flight (based on similar-sized aircraft burning 6 gph): 6 gph * 0.1 hours * 761MJ/gallon = 456MJ

So, for a 10 minute flight, you're in the neighborhood of 500MJ.

1 kWh == 3.6MJ, so 456MJ is 138kWh and the largest Teslas are in the 100kWh range.

Tesla says it can charge a 100kWh battery in that in 14 minutes on its 250kW DC charger network.

So, charging 138kWh should take about 20 minutes.

You could double or triple that for inefficiencies and other losses. But I think we're in the realm of many minutes and less than an hour. And it's certainly not under 5 minutes or multiple hours.
 
And the magically appearing infrastructure upgrades needed in the electrical distribution grid to support those loads…
 
250kW service isn't much. Every house on my street has 48kW (200A at 240V) service.

We've added dozens, if not hundreds, of houses in my neighborhood without new grid work.
 
I'll try on the math.

Mass of aircraft: 1000kg
VTOL ascent to 500m (potential energy = m * g * h): 1000kg * 9.8m/s^2 * 500m = 4.91MJ
Forward flight (based on similar-sized aircraft burning 6 gph): 6 gph * 0.1 hours * 761MJ/gallon = 456MJ

So, for a 10 minute flight, you're in the neighborhood of 500MJ.

1 kWh == 3.6MJ, so 456MJ is 138kWh and the largest Teslas are in the 100kWh range.

Tesla says it can charge a 100kWh battery in that in 14 minutes on its 250kW DC charger network.

So, charging 138kWh should take about 20 minutes.

You could double or triple that for inefficiencies and other losses. But I think we're in the realm of many minutes and less than an hour. And it's certainly not under 5 minutes or multiple hours.
I’m not sure how you can have > 100% charge efficiency. 100% would be 33 minutes.
 
5300lb MTOW, estimated 1000kg battery pack at around 200Wh/kg, dual charging cables with dual channel charging, each channel capable of supporting up to 300kW charging.

One analysis by Carnegie Mellon University engineering Prof. Venkat Viswanathan used this figure to show what it implies for the plane’s design. Joby says the S4 will have a top cruising speed of 200 mph and a range of 150 miles. The FAA requires passenger planes to have a reserve of 45 minutes of flight time over and above their advertised range. To do this, Viswanathan calculates the S4 would need a battery pack with 200 kW of energy.


Of course, battery packs need insulation and packaging to ensure a thermal runaway in any one cell won’t propagate, as well as a battery management system and some capacity for cooling. Consequently, Viswanathan estimated that the assembled battery pack would have an energy density of 200 Wh/kg. That implies an S4 battery pack would weigh 2,200 lb. (In interviews, Joby officials have claimed an even higher energy density, 235 Wh/kg.) For comparison, the Tesla Model X currently carries a battery pack sporting 186.21 Wh/kg.


 
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I still stick to my opinion. I don't think the limitation is technological. Those will be overcome by engineering and progress.

I think the issue they will encounter is a combination of economics, demand, and like the rest of aviation, regulation.

Economically I think they are fooling themselves by thinking they can produce and operate these aircraft any cheaper than existing tech. They are comparing these to the cost of a Tesla, but real costs are probably going to be comparable to a Bell.

Once the costs shake out, I think the market for them will be very limited. I'd be surprised if it was less than $500 for a 20 minute flight.

The regulatory environment we have today in aviation didn't happen overnight, it was decades of accidents and response. They may have gotten around some of this during the certification stage, but they still will have to get through the operational side. These devices may be relatively safe, but are they 121/135 level safe? What's the TBO on various components? Training to operate? What is the publics level of comfort for accidents, because they will happen? With 121 carriers, the acceptable level of risk is near zero these days.
 
They are comparing these to the cost of a Tesla, but real costs are probably going to be comparable to a Bell.
In the big picture, its actually more accurate than not. A big question across many levels is why hasn’t the aviation industry adopted more cutting-edge production techniques from other industries like vehicle production? And the answer was the previous aircraft designs could not be adapted efficiently and especially rotorcraft designs. However, the eVTOLs were developed from the ground up to use those modern techniques. And those eVTOL production lines aren’t being developed by Bell, Airbus, or Cessna. But by Toyota, Hyundai, and Honda. Plus the fact a couple eVTOLs OEMs have actually hired top-level talent from Tesla.

With 121 carriers, the acceptable level of risk is near zero these days.
True. But it took them decades of accidents to get there, yet people still boarded those aircraft. So I think a better comparison with 121 carriers would be back when people wouldn’t board a 121 airliner unless it had a propeller mounted on the front of the engine.

All new aircraft concepts have historically gone through the same public acceptance processes. So its nothing new with eVTOLs. However, I think the one advantage eVTOLs have over the last new “revolutionary” aircraft type is the level of technology available to design and operate them. And the on-going public surveys of eVTOL usage show an equal or better acceptance as past new modes of airborne transport. But as you note, time will time.
 
The whole reduced maintenance argument with EV vs ICE isn’t that drastic as one would think. EVs are less reliable than ICE so you can bet they spend their fair share in the shop. In fact, my Subaru has had less time in the shop than my Teslas. Plenty of electronics (door handles, Falcon Wing doors, displays, etc) can fail in an EV. While owners report less maintenance, when they do need repairs it’s far more expensive than ICE. Their insurance rates are far greater as well. And in most cases, you pay an EV road tax once a year. I’d also be wary of buying out of warranty more than I would with ICE.

Yeah, there’s the tax credit (if you qualify) and gas savings but it’s not a night and day comparison to ICE. Some things are better, others (range, batt cost, drive motor cost) not so much.


I’m all about EVTOLS succeeding in UAM. I think they’ll have a definite advantage over your smaller helicopters. I don’t know about the whole pilotless thing but if they can prove a redundancy or level of safety far exceeds a pilot, then why not? Same as driverless cars. I do think some of these companies (including Lilium) were / are making promises they can’t keep though. I knew that Lilium wasn’t going to get the range, payload and speed they were claiming. Kinda like some other aviation startups (Alice, Celera 500). They promote a lot of hype but ultimately don’t do any better than legacy aircraft.
 
They are but the repair costs for EVs are much higher than ICE.

I'm not clear on that article at all. It's saying that the cost of repairs is higher, but it doesn't seem to be saying (at least not out right) that the cost to keep a car running is actually higher. The difference being that if something breaks it costs more to fix it, but do the things that are more expensive on an EV break often enough to make it actually cost more on average?
 
I'm not clear on that article at all. It's saying that the cost of repairs is higher, but it doesn't seem to be saying (at least not out right) that the cost to keep a car running is actually higher. The difference being that if something breaks it costs more to fix it, but do the things that are more expensive on an EV break often enough to make it actually cost more on average?
The number of times an EV requires maintenance is less. So the experts say. That statement contradicts the fact that EVs are less reliable than ICE though. I guess they break a lot…but don’t go into the shop as much. I can tell you this, in my experience with electrical gremlins in Teslas, if you give it some time, it usually resolves itself. :biggrin:

 
Reliability of EVs takes into account all the recalls that are just software updates.
EVs are dramatically more reliable than ICE cars, since they have far fewer moving parts.
They also require little or (usually) no maintenance for the first 200,000 miles or so (which is when they may need new brake pads).
 
There’s more to it than software updates.

If they were maint free, you wouldn’t have so many complaints about service centers. 1.7 star average. Somehow they have high customer satisfaction though.


Maintenance savings “marginal” after 40,000 miles. Lucky they didn’t need any body work.


 
I knew that Lilium wasn’t going to get the range, payload and speed they were claiming. Kinda like some other aviation startups (Alice, Celera 500). They promote a lot of hype but ultimately don’t do any better than legacy aircraft.
For S&G I looked up Celera to see whatever happened to them and was amazed at what they are alleging now. You have to see it, and you'll never guess who's running their C-suite.

Otto Aviation
 
EVs in general, I can see having issues. Many of the manufacturers are still on their first-generation EVs, and they're just not very good at them yet. Companies like Tesla and GM that have been doing EVs for a while should, IMO, be more reliable. However, that particular study goes back to the 2000 model year, so it's covering everybody's first-generation EVs. I don't think it's particularly relevant to look at an EV1 to decide whether a brand new Silverado EV is going to be any good. Same with a Tesla Roadster vs a Model Y.
If they were maint free, you wouldn’t have so many complaints about service centers. 1.7 star average. Somehow they have high customer satisfaction though.
Nobody likes going to the service center, regardless of what kind of car it is. It's annoying, kinda wrecks your day, and costs a lot of money.

In nearly 70,000 miles, I've had my Tesla into the service center four times, and two of those were due to FOD encounters (screw in a tire, and two bad windshield stone hits in quick succession). I've knocked a couple of plastic pieces loose and had them refitted.

In terms of maintenance not caused by outside forces, I've had the tires rotated, and I've had the cabin air filter replaced and ducts cleaned out a couple times (HVAC system design can cause a lot of condensation that causes smelly things to grow, it now operates differently thanks to a software update and no longer has this issue).

And I've put washer fluid in it.

Somehow, the factory wiper blades are still good. Brakes will last forever, and I use the actual brakes just often enough to keep the rotors from rusting. I'm about due for a new set of tires.

It's amazing how little needs to be done when there's so few moving parts, so much less vibration, etc...
 
For S&G I looked up Celera to see whatever happened to them and was amazed at what they are alleging now. You have to see it, and you'll never guess who's running their C-suite.

Otto Aviation

I guess I missed it, what are they alleging now? And who is the standout in the C-suite that is supposed to be attention grabbing? The jet looks pretty sweet, though.
 
I guess I missed it, what are they alleging now? And who is the standout in the C-suite that is supposed to be attention grabbing? The jet looks pretty sweet, though.
Miraculous capabilities on paper and Ex-CEO of Boeing, Dennis Muilenburg. What could possibly go wrong?
 
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:lol: definitely missed that he was on there
 
Archer seems to have a good design as well.
They're also well into the FAA certification process at Phase 3. But Archer, Joby, Electra, and Beta are the 4 big players at the moment IMO. The Electra and Beta are pursuing Part 23 cert with a Special Condition standard for electric-propulsion and Archer and Joby are using a Part 21 Special Class standard for the whole aircraft. Lot of momentum with those 4 OEMs.
 
I have yet to see any economics forecasts that says there's actually a business model for these that makes money, outside of extremely dense cities like NYC. In those, I can see these replacing helicopter services that currently exist, IF the cost of the machine & repairs are at or below helicopter costs. It remains to be seen; I have a hard time believing something with several rotors will be cheaper than 1 big one, and at the volume of production, how any part will be cheaper long term.

I think these are a stepping stone to hydrogen vehicles, though. A hydrogen electric cell like what Joby is playing with could replace a lot of small GA aircraft, and they're doing it in a non-traditional way. Their innovation rate is a LOT faster than the traditional aircraft makers, and if they're successful, Piper, Cessna, and Lycoming have the most to be afraid of, and it'll be their fault for sticking with 75+ year old technology without real innovation. Still, I think that's 10-20 years out before any of them are a significant player in that market.
 
Not VTOL, But I've seen the electric Pipistrel, I think it will work sooner rather than later. Batteries need to get an order of magnitude cheaper and lighter but that's gonna happen.

Not surprised they ran out of money though. Breakthru technologies are expensive.
There's no indication that any proposed battery technology will have more than four times the energy density of lithium-ion batteries, much less a tenfold improvement, and that improvement on a commercial level is years away.
 
On another cost level, most current eVTOL designs are nowhere near the complexity of even a 172. For example, a 172 engine has 100s of individual parts vs a Joby engine with only 10-12 parts. Add in eVTOLs will be produced in similar fashion to modern vehicle production lines vs the hand-made methods for a 172. And so on. So actual acquisition costs are still only projections as are how many units will be produced.
Where will the demand for assembly line built EVOTLs come from? Eclipse Aviation was going to build thousands of microjets. How'd that work out?
 
have yet to see any economics forecasts that says there's actually a business model for these that makes money, outside of extremely dense cities like NYC.
That’s because eVTOLs were designed for densely populated urban areas and UAM. When you get outside of those areas it falls more under the RAM side of the overall AAM market. And it’s the RAM side that has been using the hydrogen based fuel cell technology and flying several prototypes but does not have the same investment base or support. However, I think you’ll see turbine-electric power sources used in conjunction with battery packs at the eVTOL level before H-fuel cells due to scalability issues.

I have a hard time believing something with several rotors will be cheaper than 1 big one, and at the volume of production, how any part will be cheaper long term.
In general, it’s the simplicity of the design and components of an eVTOL vs a helicopter that makes it initially cheaper. For example, the eVTOL engine has 6-12 parts vs a helicopter engine with 100+ parts. Add in the eVTOL engine uses a number of existing off-the-shelf parts vs the specifically produced parts for your average turbine engine. Also they will use modern automated production methods vs the "hand-made" methods of most conventional helicopters. In the end, I think the costs will be much closer to vehicles production costs in the long term especially given who will be running most of the eVTOL production facilities. Who knows, maybe once these newer production methods mature, Cessna or Piper might be incentivized to design/produce a new small Part 91 recreational level aircraft everybody supposedly wants?

Where will the demand for assembly line built EVOTLs come from?
Initially, I think you’ll see the demand for pax versions will be overseas as their urban transport plans are already based on “public-transport” more than private transport (vehicles) like in most US urban areas. But while it doesn't get much press, the specific market that will really drive that initial demand in the US will be cargo/logistics support on both the civil and military sides. Both Joby and Archer have cargo versions. For example, one of the few real-world UAM test programs using helicopters concentrated only on the cargo side within a congested urban environment and met or exceeded all the goals of the test except the noise levels.

On a completely different level, the Joby and Archer were also designed for remote pilotage and automated flight. So if you read up on where the commercial drone industry is going and what the proposed new Part 108 will cover, those 2 aircraft could easily be used as a big drone as well. For example, several Chinese eVTOL OEMs certified/are certifying their cargo versions first and the pax version 2nd with, I believe, Autoflight already flying CAAC “Part 135” remote-pilot cargo proving routes for their AOC.

Eclipse Aviation was going to build thousands of microjets. How'd that work out?
From a historical point, I think a better example would be the initiation of helicopters or jet airliners into the civil transport system as both were "huge" technological advancements at the time similar to eVTOLs today. At least based on my experience and knowledge.
 
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