Oh come on. Run some basic numbers re fuel energy density of hydrogen vs liquid hydrocarbons like petrol then do some basic calculations re volumes and storage (liquid hydrogen and/or compressed gas) and then look at the weight of the tankage..... etc. etc. Lets not even get into the weight, efficiency, and output of fuel cells; a battery system would be necessary for surge energy demands like take off, adding weight....

I have run these numbers many times and there is no way an aircraft is going to fly for any reasonable period of time using hydrogen as a fuel, especially a vertical machine; factor in endurance then just laugh. It just doesn't work, both from a weight and a volumetric perspective; let's not even talk about how hydrogen is produced, sources (probably a steam process on natural gas), energy requirements for chilling and liquefying the gas (pressure tanks would be WAY too heavy for aircraft), and the infrastructure to supply the fuel...... More grabbing headlines and money here, IMHO; buy stock early and then bail when the time is right..... The only hydrogen craft I see flying passengers are balloons, blimps, or dirigibles.

Neighbours and local residents of hospitals in Germany are going to court against EMS helipads beccause of noise already nowadays. What makes people think that helipads for THESE things will be allowed in cities? There's a reason there's no helipads in larger cities except hospital pads. Not going to happen :=

And here's the latest wet dream from the "gimme some development money" crowd:

https://cimg3.ibsrv.net/gimg/pprune....bf433dce0c.png

Not a lot of lifting surface for forward flight, and the wing has big holes in it with drag-inducing fan stuff.

The noise from those 2 piddly propellors (nose, tail) must be a real scream.

I am impressed by all the money they collected but does this new design mean their own original tilt-impeller concept finally did not convince them?
Now it looks more like a toy. Love those tiny front and tail propellers.

Pretty funny. But you have to understand they are turning a 50,000 rpm ± so the craft is supersonic....... I wish I could come up with one of these schemes for instant wealth.

All the laurels for Bezos and Musk who fund their own visions. But should the more general financial community get a better technical education to prevent them from all this fantasy financing? How bad will risk capital investments be in other less visible areas, say bio, AI and quantum computing, if even this vapourware gets funded with hundreds of millions of dollars?
We might need stricter rules to prevent money getting extracted from funds on -hopefully not- intentional fake promises.

The photo posted by Charlie is not anything to do with Lilium.

Let me provide the missing source:

Ascendance revises the design for its long-range hybrid eVTOL (newatlas.com)

Thanks for the clarification, a bit confusing to distinguish all those phantasies.

Oh geez, another one:

They have ordered the Embraer EVE toy.

Sydney Seaplanes has the advantage of Grandfather Rights on the Rose Bay flying boat base, and they do trips to Palm Beach and other places in Pittwater.

Back in the 90s we proposed a floating heliport to use this pre-approved water runway, the pontoons would have been designed for the task, but the EPA and Sydney MSB pounced on it for noise considerations. No landing was allowed within 1000m of the shore, which meant that there was a lot of moving the pontoons between flights, or using water taxis, both impractical. And the rabid Labor voters of Balmain stopped anything west of the bridge.

Be interesting to see how they plan on landing at Barangaroo, on the west side of the bridge and almost requiring an approach/departure under the bridge.

The comments section in this link makes for interesting reading.

Monte-Copter Model 15 Triphibian helicopter - development history, photos, technical data

Even though the design still looks quite futuristic 60 years on I doubt the early investors will ever see their money back.

Lilium employs Andy Strachan as test pilot
 

The money keeps flowing for development.
The move to Spain to allow higher speed testing. Former RAF and Leonardo helicopters pilot Andrew Strachan steps up as test pilot.

https://lilium.com/newsroom-detail/l...ndrew-Strachan

Mjb

Looks like they are only flying RC models; that company website is absolutely devoid of actual hard information.

https://www.ainonline.com/aviation-n...-lilium-evtols
Hmm I wonder if Net Jets actually put any money down , if so they are either longsighted visionaries are complete idiots ,
Please send your vote on a 20$ bill to . Makemerich@[email protected]

Ilium says they will be all set, certified, and flying in 2024..... From their website:
From FAA.gov

Which might not include the time to establish a changed certification basis and special conditions, which could be necessary if the conventional power off landing requirements cannot be demonstrated. This type of aircraft will succeed, but acceptance for commercial fare paying transport will be a little further off, while operating standards are adjusted to accommodate a changed certification basis.

An analysis of Lilium by Iceberg, financial and accounting fraud investigators.
https://iceberg-research.com/2022/03...cenbsp-strong/

And a Youtube glowing review.

Can someone explain what is meant by this statement by Lilium, I tried a search on Helicopter footprint and the only references are to a noise footprint. https://ir.lilium.com/techfaq
'In the Lilium Jet we are using electric ducted fans for propulsion. The advantage of the ducted fans is that they are much smaller than open propellers to lift the same weight of an aircraft. Or in technical terms - they can operate in high disc loads. The consequence of this is that VTOL aircraft using ducted fans need less ground footprint for a given weight and passenger (PAX) capacity of the aircraft. This in turn creates the potential to scale the aircraft to higher PAX and take-off weight for a given size of landing infrastructure'

Somebody please wake me when its over

footprint in this context just means the physical surface area required. They are saying for any given area, they will be able use an aircraft with a greater payload.

This thread is approaching it's 6th birthday, how many candles will be on the cake celebrating the maiden commercial flight?

Mjb

New test flight video
 

Two videos.

45kts test flight

Interview with engineer
Mjb

Houston, we have transition
 

Lillium state this is the first transition from hover to wing-borne flight for a full scale, all electric aircraft.

130Kmh, 1200fpm climb.
Transition occurs at 1:30 in the clip.

Mjb

mjb, as I watched the video, I wasn't sure if there was a person in the aircraft. Was that whole flight accomplished remotely?

All Lillium flights to date have been remote. This is due to both pilot safety and pilot mass. They have barely enough battery energy to fly, a pilot’s mass on board would make it almost impossible to leave the ground.

Specs announced
 

Latest video today from CTO Alastair McIntosh, states the range and power density. They apparently have confidence these specs can be achieved, a range of 250km empty operational and 175km max take off weight. They state with a run-on landing the range will increase ( as the hover landing phase uses more juice)

This is the most revealing video thus far, they outlined the finalised design of the production model.
As CTR states, the battery density of existing commercially available technology is a hurdle. In this video they claim new battery tech will deliver the stated range and a full payload, presumably full payload is a person in each seat?
In other videos they mention the production model will have 7 seats and 30 engines (The prototype is full scale 5 seater with 36 engines)
The engine guru states there will be a mechanical connection to adjust flow to optimise energy use between landing and cruise. (10x more energy required for the hover) This is a repeating theme with electric aircraft, hover phase is a means to an end, gas powered helicopters will rule slow orbit tasks until battery density is improved.

To put it in perspective, this is almost the same range as our VW ID4 Life model. (Shorter range battery, less tax)

What about take off?
I don't foresee these ever taking hold as rooftop delivery for pax, but on shorter controlled fields in well regulated air corridors.

A short takeoff could be assisted with a cable tow, similar to gliders, but may not be what passengers might appreciate.

My take-away is: 9 times more power to hover than to cruise. A conventional helicopter is close to 1:1. It starts to worsen with tiltrotors. Then there are those oversized multicopter drones. Did Lilium chose the worst way to hover?

https://aviation.stackexchange.com/q...-when-hovering
i don't think there is a helicopter that burns same fuel in hover as fwd flight ,I am sure ratio is much better than 9 to 1 though
.

You are looking at it the wrong way - It has fixed wings , which is makes it much more efficient in the cruise than a helicopter. So, its not that it is inefficient hovering, it is instead more efficient in forward flight.

Rotors are wing surfaces. You'd be surprise how much lift they produce in forward flight.

They are quite inefficient. The retreating blade is the limiting factor, with only around 40% of it producing useful lift, and at a high AoA with resultant drag.

The advancing blade has to throw away all that beautiful lift it gets from the added forward airspeed, to match the poor old retreating blade.

If both blades were advancing, lotsa lift both sides, no need to worry about retreating sides, hence the ABC test aircraft and Hokums and intermeshing tandems.

They only quote the run on landing in the context of flight endurance for certification for commercial flights.


Mjb

Dissymmetry lift is not 0 lift at retreating side and plus with multi blades also gets the benefit of multi wings instead of a pair. And rotorcraft limits 150kt Vne not only preventing shock wave but also to make sure retreating blade still plane air faster than relative air flow.

Powered flight always been dealing with dilemma of disproportion power requirement between MTOW and cruise. Compound design like lilium is one of those went physically challenged approach to this. If they resort to running takeoff, might as well venture into extreme STOL dropping the expensive vector thrust part. I predict first 10 years into the market operation will be limited from airfield of some sort instead of helipad. And a super STOL might even be a winner.

Never said it was 0 on the retreating side, just that the limit to the aircraft's lift generation is the retreating blade.

Be nice to have an advancing blade on each side, and not have to worry much about the retreater.

Or a conventional helicopter... With these much-awaited (still non-existent) great batteries, right-sized motors... ground effect, translational lift, well-understood flight regimes...
And what about the very high nozzle velocity of those tiny fan-jets? Ultraclean FOD-free Lillipads?

Endurance seems, to me, to be the big problem. With the much bigger power demand with a vertical landing and take off, a go-around would see to be a real deal breaker for certification. As for the machine(s) as extreme STOL, that seems to totally destroy the entire concept of their potential use as some sort of city air taxi. How did the New York rooftop helicopter flights turn out? Probably a good reference. I suspect their business case with the huge number of passengers is a bit off the mark....

Does their claimed range include 30 mins reserve? If not, why would CA$A approve them to operate with less reserve than a real aircraft?

An in depth assessment of Lilium by Leeham News, worth a read.
https://leehamnews.com/2022/07/29/bj...lium-jet-vtol/

Thank you for the article link. Excellent article.