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.
I don't have a particularly positive or negative opinion of the technology here, but the one good reason I can see to treat these machines as inherently dangerous is because they take all the kinetic energy of something traveling faster than a car and add the gravitational potential energy of something hundreds of feet off the ground, while not being constrained to a well-defined corridor that you can protect with safety barriers.
When cars meet stationary objects at speed they tend to make a mess. These things are likely to be lighter, but when out of control they'll be going faster, and this thing specifically, when it goes bad, will go bad carrying several hundred kilos of lithium into an uncontrolled energetic event.
If risk is probability times expected outcome, my estimate would be that Lilium comes out worse than driving on both sides of the formula. That's not a reason per se not to do it because, like you say, let's gather data. But the basic physics of the situation is also not something to ignore.
A) The reason that cars crash (crash meaning doing damage in the process of failure) is by a large margin not mechanical failure, but human error. While in this case the technology is still infantile and will, even after a couple of years of testing, certainly be more prone to mechanical failure, I see no real reason to assume that it would ever be permitted for actual inner city usage before it beats a certain range/failure-ratio, because that seems trivial to secure and exactly what regulatory bodies are made for.
B) Let's assume there will be no humans piloting these things in an urban transportation scenario, ever, because that does indeed seem incredibly dangerous and silly. I don't think we as a species have the capacity to manually navigate these things in a 3d space filled with them. I don't see any reason we have to. Let's not do that.
C) If you think about it, physics are impossibly bad for car safety. There is no time to decelerate safely and then also no safe space to evade to. In contrast, in the case of flying thingies however, you have space and time working for you: Even if parts of the machine fail, it definitely has at least an order of magnitude more seconds to manoeuvre to relative safety. Of course, catastrophic failure (big fireball in the sky) can possibly still occur (I assume), but you are not working against physics, which is great, because then all you need is outstanding engineering and appropriate fail safes. Engineers will take that over having to beat physics any day.
Advances in ai, energy storage etc.
But right now, air taxi is just inherently stupid.
We know how to build those things. There is nothing really you need to invent. you just need to build them.
The problem are things like safety, airspace (who owns it), co2, terrorism, airspace Management...
Let's talk air taxi again when we can fly fully electric, are in the right way for climate change and when air control is no longer handled by humans.
With C, we're well into "what do the safeties look like" because the assumption that you can manoeuvre at all after something Unexpected And Exciting happens is possibly rash. I don't trust that designs like this one have much unpowered lift or even that much flight control at all in a power-out state. And remember too that the whole point of these things is that they're flying over presumably dense areas. The idea that there will be somewhere safe to manoeuvre to in the seconds you may or may not have is definitely on the optimistic side.
But still, even given all that, a parachute should go a long way to being a workable "emergency stop" equivalent. There are failure states which it doesn't help with (for instance: a birdstrike goes badly enough wrong that a short-circuit starts a lithium fire which, thanks to our parachute, slowly drifts an incendiary path across entire city blocks) but in general I'd expect the benefits to outweigh the risks.
Planes will not be a solution for all transportation needs, but where it makes sense they're great. A flying bus basically, routes can be very flexibly changed depending on evolving needs.
Public transport is factors more efficient than air travel.
And yes including initial cost.
We build infrastructure to last not to throw it away 5 years later.
You need to understand how much more energy it actually costs to bring a plain up in the air and down again. We talk magnitude more energy than trains.
We can talk about this again in 20 years when solid state batteries are broken through.and sustainable energy sources are the norm.
Air taxi's ate not hard to build on a technical level. We know how to build them.
And honestly we didn't do a good job. After all climate change is real, lead poisoning was real too.
Humans? A uneven roof? A busy road?
And for whom? The rich? People who can afford a few hundred dollars for a quick flight from the airport to the city?
How about no?
For example, to fly a helicopter over London requires pilots to fly only over well defined routes - although those with multiple engines are allowed more scope.
2020: 94 accidents, 19 fatal accidents, 35 fatalities, 22% decrease in accidents compared to 2019, 36% decrease in accidents compared to 2013
2019: 121 accidents, 24 fatal accidents, 51 fatalities
2018: 122 accidents, 24 fatal accidents, 55 fatalities
2013: 146 accidents, 30 fatal accidents, 62 fatalities
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).
They will probably want to fly across non easy terrain because otherwise you could just use some other means than an expensive helicopter.
Hight perhaps but you will fly across water, woods, power lines, cities.
That’s so the craft can stay in the “autorotation possible” section of the HV diagram as much as possible.
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.
This is why you rarely see them do that, instead they circle - which any small plane could do but the helicopter can hover if needed. It’s just the most dangerous part.
There's also a lot of other things that can impact the event - for example, the crash I mentioned involved bad weather, tired crew, and losing both engines at once due to icing. They autorotated and nobody died... but they fell into a forest, landed hard enough to destroy undercarriage, and the first officer survived by accident due to helping get passengers into position when a tree smashed his station.
EDIT: corrected captain to first officer, as visible in this photo: https://static.polityka.pl/_resource/res/path/bc/08/bc086fae... (it's Mi-8, so captain sits on the left, not on the right as is normal in western helicopters)
Control authority yes, but altitude is always a substitute for forward air speed (and is an even better substitute for the eVTOL planes than helicopters).
That’s kind of a given, since the successful autorotations do not qualify as crashes.
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.
Wait until you see the motor carriages they claim are going to replace horses one day.