PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rotorheads (https://www.pprune.org/rotorheads-23/)
-   -   Lilium vertical take off "jet" (https://www.pprune.org/rotorheads/578979-lilium-vertical-take-off-jet.html)

Winemaker 30th Nov 2021 01:32


It will be fueled by hydrogen, the most sustainable technology in development today.
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.

muermel 30th Nov 2021 15:13


Originally Posted by Less Hair (Post 11148543)
Will the noise and the blast when hovering make it acceptable for inner city and metro area flight operations?

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 :=

Ascend Charlie 3rd Dec 2021 23:57

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.

Less Hair 4th Dec 2021 03:20

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.

Winemaker 4th Dec 2021 03:43


Originally Posted by Less Hair (Post 11151094)
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.

Less Hair 4th Dec 2021 07:41

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.

netstruggler 6th Dec 2021 11:03


Originally Posted by Less Hair (Post 11151094)
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.

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)

Less Hair 6th Dec 2021 12:02

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

Ascend Charlie 6th Dec 2021 20:52

Oh geez, another one:


Sydney Seaplanes orders fleet of electric air taxis to provide escape from Sydney traffic


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.

cattletruck 16th Dec 2021 09:26

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.

mickjoebill 31st Jan 2022 22:38

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

Winemaker 1st Feb 2022 14:25


Originally Posted by mickjoebill (Post 11177966)
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.

widgeon 4th Mar 2022 16:49

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 . [email protected]@me.rus

Winemaker 5th Mar 2022 16:51

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

Lilium is aiming to certify its eVTOL and start commercial services in 2024.
From FAA.gov

......the certification of a new aircraft type can take between 5 and 9 years.

Pilot DAR 5th Mar 2022 18:24


......the certification of a new aircraft type can take between 5 and 9 years.
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.

sandringham1 16th Mar 2022 19:29

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

And a Youtube glowing review.

sandringham1 21st Apr 2022 13:19

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'


Protolanguage 21st Apr 2022 18:24

Somebody please wake me when its over

212man 21st Apr 2022 18:45


Originally Posted by sandringham1 (Post 11218885)
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'

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.

mickjoebill 22nd Apr 2022 12:55


Originally Posted by Winemaker (Post 11195225)
From FAA.gov
Quote:
......the certification of a new aircraft type can take between 5 and 9 years.

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

Mjb


All times are GMT. The time now is 03:19.


Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.