The Lilium Jet does not appear realistic to me, most VTOLs barely fly in the best of circumstances. It seems more like a scam to me. Not my field so I could be wrong but the added efficiency of a canard is small change compared to the other challenges involved.
Perhaps VTOL is entirely impractical and has no sizeable niche, but it appears Lilium is the least wrong out of all the existing VTOL physical layouts.
- No additional draggy/heavy structures for the VTOL components, they reuse the existing wings
- No large exposed props, which have noise and hazard concerns
- Propulsors are synergistically combined with the wing upper surface, enhancing lift during cruise
- VTOL mode actuators are synergistically combined with ailerons/elevators, reducing part count
- They have wings for efficient long-distance flight (surprisingly some don't!)
- Contingency ability for runway landing if the battery is too depleted
- The aforementioned canard advantage
If any of the VTOL schemes are workable (which is admittedly an open question!) it will be Lilium.
On that case, past performance is absolutely not a guide for future results.
The weight/power ratio of electrical motors is so different from combustion engines that it's a qualitative difference already. Just because nobody has ever been able to solve that problem, it doesn't mean that a lot of people won't easily solve it now.
It appears you’ve drunk the coolaid. I looked into it more and can now confidently say it’s a total scam. The stuff you’re talking about is window dressing.
Maybe that's true! If you can elaborate on your confident saying with facts, sources, or explanations, I would certainly give it my full consideration. It wouldn't be the first time I've been wrong!
What I was looking for is someone to say it can’t work because of the math XYZ and for a person to say back that math XYZ is wrong because of ABC and that second part never happens.
The stuff they talk about is window dressing and doesn’t answer questions like, where are your 500wh/kg batteries?
I remember when Ballon Boy happened and I took one look at that Ballon and it was instantly obvious it wasn’t carrying a kid, but apparently others were still expecting to see a kid when the balloon landed.
That doesn't answer my question. It just hides your 'scam' claim within your prior.
_Why_ is your a priori expectation for all VTOL to be a scam? And does that generalized reasoning in fact apply to the specific case of Lilium?
>where are your 500wh/kg batteries
That's probably the least speculative out of all their bets. Moore's Law for microchips may have ended, but a similar (slower) scaling law for batteries seems to be holding for decades now.
My prior is that batteries will continue on the same curve.
You can also check out their stock price. Down from peak 92%, so at least to investors it’s looking less likely they’ll deliver instead of more likely.
I gave a link in which others listed their rationale for why they don’t think it will work.
Their availability estimates for battery capacity is double the long term rate of improvement - which seems unrealistic. But yah know with enough wh/kg just about anything will fly.
Imagine thinking stock price pegged to peak price indicates company value. :-/
> I gave a link
From your link:
> my engineering mind recoils at the complexity of the design. The variable pitch blades, the adjustable exhaust nozzles, the tilt-wing vectored thrust system, etc. With complexity comes...
The variable nozzle is still present[1], but Lilium long ago dropped variable pitch[2]. "Tilt-wing" is also inaccurate, since they only move the (already moving) aileron and elevator surfaces, not the wing and its associated structures.
Hopefully this can help clear up these (hastily-Googled) concerns.
>Their availability estimates for battery capacity is double the long term rate of improvement
This is an interesting claim that I'll look into, thanks. Do you have a source? I found a few slide decks but I couldn't immediately find this part, so any help would be appreciated.
I do expect in the nominal case that Lilium will take perhaps twice as long to come to market, so in the end the delays may roughly cancel out. Time will tell.
Note that battery density will effect all eVTOL startups equally, so it's not really a competitive disadvantage for Lilium per se, but rather an overall industry challenge. And I agree, there are many challenges facing the industry!
What you have shown me has not convinced me to change my opinion and I'm not trying to change yours. The people that I know in the industry focus on certification timeline being overly optimistic which while most defiantly true is less interesting to me than the battery tech, or even the sociology as to why people get so attached to this - like that Nuclear-Powered Sky Cruise concept that many people shared unironically.
No doubt a lot of amazing things can happen with an large increase of wh/kg which is why I think it's incredibly weird that so much effort was put into things that are not that, Lilium has special investments in battery tech with Ionblox, the only interesting question to me is 'is that paying off?'. Not how much % of efficiency can be saved with a canard design - that's window dressing. Also, if they have this amazing battery tech then isn't that the most valuable thing they have and is eVTOL really the best application for it, why not double the range of electric cars instead. Even if they think eVTOL is the best use case then why not run on a skeleton crew until the battery tech arrives, or at least properly test their designs with onboard generators.
Waiting for battery tech is like waiting for engine tech and since so many engines end up vaporware so do all the nice aircraft designs dependent on them.
But sometimes new engines do deliver. The RED Aircraft V12 engines are amazing and should enabled the Otto Celera 500L to work really well. The DeltaHawk engine but they might actually end up delivering a really nice reliable engine. Part of that is a combination of long term stagnant general aviation engine technology and reduced tooling costs for manufacturing with CNCs. So there was a lot of low hanging fruit waiting to be picked.
Obviously Lilium Jets initial claims were wildly unrealistic, I think their current claims remain unrealistic, perhaps by the time they 'deliver' they've scoped it down to small hops. If they plan on selling something that can carry 7 people (they've already sold 20?) then perhaps I would believe it more if they demonstrated something working with 1 person and a whole lot of performance to spare.
All of these electric VTOL urban air mobility things are hopeless. Various tech companies including google have taken a stab at them over the past two decades and none are anywhere close to entering service. Google shut theirs down. I really want them to work, but nothing gets past the physics/economics of batteries having piss poor energy density relative to fossil fuels and the massive inefficiency of small rotors. I think Boom has a better chance of flying than Wisk. Meanwhile, Uber Copter is up and running in NYC with regular helicopters.
Well a scam that is flying and more or less working as advertised at this point. You can watch testflights on youtube. Same for the Archer, Joby, Beta Alia, and a few others. Several of those are now doing manned flights and shipping prototypes to early customers.
In short, they fly just fine. What makes you think things are a scam?
Well, what Lilium is flying is a demonstrator, not a prototype. The difference is that a prototype is close to the final product and test flights can be used in the early phases of the certification path, demonstrator flights cannot. Or to put harsher: all Lillium has is two model aircraft that have close to nothing in common with the 7 seater they are selling.
And one could call it a scam, when tuh product you sell has nothing to do with the product you show (and no, mock-ups at airshows don't count at all), and the product you sell has, so far, no clear timeline until certification. The aerospace version of vaporware. Whether or not it amounts to an actual scam woupd be for courts to decide. Right now it looks a lot like Nikola, without the option to use a hill to fake the product demo.
As a sidenote regarding test flights: last time I checked, those were unmanned, with a demonstrator and not a prototype and no longer than 6 minutes. Which is as far from what serious people in the field call a test flight of it could be. Good for PR and investors so, it looks cool.
Also, one can make everything fly, if you put enough thrust to it. Doesn't mean you have product that can sustain a business.
That prototype/demonstrator (let's not get silly about words here) looks like it's actually flying properly though. Transitions to horizontal and vertical flights and all. They are planning to have the first manned flight end of this year.
A scam would be intentionally misleading people about the ability of this thing to fly at all and then grabbing the money and run.
scam would also involve disgruntled investors trying to sue and getting their money back. There have been a few such cases about investors wanting their money back. But the headline is that Lilium is continuing to raise lots of money and making steady progress to getting their products launched. And those court cases seem to be going nowhere so far. The nature of VC funding is of course that things don't always go to plan.
Just because this company isn't satisfying your need for instant success and instead is following an entirely reasonable path to certification, which is slow for any airplane, doesn't mean it's a scam. By that logic anything is a scam until it emerges fully designed and manufactured on the market. That's not how things work in the real world.
This thing has investors, prospective customers with letters of intent, and flying prototypes.
Nikola is actually shipping trucks at this point too. Yes, they got caught with a non driving prototype running downhill and they got punished for that and the CEO might do some jail time for that. But the thing works now and they are selling lots of trucks that actually move cargo around. A scam would have been if the thing proved to be vapor ware. As it turns out, it wasn't. It was just running a bit late.
I haven't been following those, but the GP's question wasn't about any of the things you enumerated.
The big question is: have they demonstrate a loaded plane flying through a useful distance while keeping enough reserve energy for satisfying the safety requirements?
Their videos are very well produced explanations about everything but this. There's some stuff about a few changes that reduce the reserve requirements, but still, I couldn't find anything about range.
That usually comes after certification. Which some of these things are getting close to. I hear Delta is eager to start shuttling passengers from their terminals with Archer. At this point, you can start making some pretty informed statements about operational cost too. Battery life span and cost is a known factor. The cost of electricity is a known factor. There might be some nasty surprises with components, manufacturing, or scaling up production volume of course.
But mostly these things are starting to look like they are getting there.
