First Personal VTOL Flight Vehicle By 2018, And Its Electric (video)


Lilium Jet - Personal VTOL jet with 500km/310 miles range...that you can plug in at home!

Lilium Jet – Personal VTOL jet with 500km/310 miles range…that you can plug in at home!

The dream of the personal flying vehicle has been around since the dawn of the airplane and science fiction itself.

Personal freedom in aircraft could arrive by some form or other

Personal freedom in aircraft could arrive by 2018…in some form or other

Thanks to advancing battery and computer technology, Lilium Aviation says its Lilium Jet could make that dream a reality by 2018…and that timeline has to be real because the company has a countdown timer right there (halfway down) on its website.

The Lilium Jet, is an electric, personal aircraft that seats two and is propelled by 320kW battery-powered fan motors.

Not only that, it is a VTOL plane, so it requires only a open space of just 225 square meters to take-off and land…so you can just park it in your backyard.

Take-off and propulsion is achieve by 36 ducted fan motors (12 per wing and 12 in swivelling nacelles from the nose).  Total output is 435 hp, the jet has a cruising range of 500 km/310 miles and can travel at speeds up to 400kph (248 mph) with a altitude ceiling of 9,000 ft.

Best of all, and unlike a helicopter, not only is it much quieter in operation, the jet is “easy” to fly, as a computer controls all the tricky take off and landing aspect of VTOL.

The Lithium Jet would also be classed as a Light Sport Aircraft in Europe, meaning only a pilot’s licence requiring 20 hours’ minimum training would be required to operate.

If such a plane were to become a viable offering, it would be easy to imagine how autonomous technology could quickly take over most of the operation.

Lilium Jet has a crusing range of 500km

Lilium Jet – redefining the suburbs for the upper class, and getting you “where you are going” at up to 400kph/248 mph

A statement and press release was sent out via the European Space Agency (who also seems quite taken with the project) earlier this month:

Also good for the roof-top of your skyscraper

Also good for the roof-top of your skyscraper

“Our goal is to develop an aircraft for use in everyday life,” explains Daniel Wiegand, CEO and one of the company’s four founders.

“We are going for a plane that can take off and land vertically and does not need the complex and expensive infrastructure of an airport.

“To reduce noise and pollution, we are using electric engines so it can also be used close to urban areas.”

Lilium AviationESA, BBC, hat tip to Peter H!

Category: General


107 responses to "First Personal VTOL Flight Vehicle By 2018, And Its Electric (video)"
  1. Mister G says:

    Holy we have to worry about aircraft falling on people at any given time and place.LOL

  2. Jason says:

    Cool plane!

    It took me a second to realize VTOL meant vertical take off and landing.

  3. Robert Middleswarth says:

    Any idea on Cost? If they can get it under a 1/4 million it could be a game changer. Is they can get it into Tesla cost it could be disruptive.

    1. Jim Whitehead says:

      Cost? If you have to ask, you can’t afford it.

      That 320kw Battery sounds very fishy to me. Tesla batteries weight over 1200 lbs for just 90kwh. If it only flies only 1 hour per charge,how can a plane take off vertically dragging the extra dead weight of ~4000 lbs of batteries?

      Flying cars have been tried since the 1960s. They never seem to work right or they crash and kill their owners. So Investors beware!

      1. Priusmaniac says:

        The Tesla Model S 90 in Ludicrous mode gives 396 KW of power which is more than the 320 KW.
        Power and energy content are two different things.
        They also use the 320 KW only at take-off for a very short time, after that they only need a fraction, if not a tenth of that power.

      2. Rob says:

        You missed the bit about the mains lead then…

  4. Doggydogworld says:

    All the weight is forward of the wing. That’s……. novel 🙂

    1. Rich says:

      I would never get in one of these. If they design it so it can glide to the ground in case of a power loss, then it would be an interesting concept.

    2. arne-nl says:

      It’s more of a flying wing design I guess. The body creates the lift more so than the wings.

    3. Fred says:

      Far from it. Most of the weight will (probably) be concentrated in the motors and the batteries. I can see the batteries being carried in the wings and behind the cabin. The fuselage structure could be a very light monoqoque carbon fibre composite construction. Because a great proportion of the lift would (clearly) be produced from the fuselage, the center of lift vs. centre of mass would be close enough.

      1. Bone says:

        These are good points. In addition the shape of the rear tip of the body seems to bend upwards to create some downwards force on the rear.

        Center of gravity is in front of center of lift in traditional aircraft, too.

      2. Doggydogworld says:

        200 kg of batteries and ~80 kg of fans may be in the wing. But ~40 kg of fans, ~60 kg of fuselage and 200 kg of humans are in front. Even if you got that body to lift ~300 kg at 300 kph (unlikely), it would crush your overall L/D ratio. Forget 28 kW cruise. Double that, maybe.

    4. David A says:

      There are front nacelles that create additional lift; they appear to retract when parked.

  5. Alan says:

    Francisco Scaramanga had something similar in the 70’s !

    1. Doggydogworld says:

      Gary Moller has been raising money for his Skycar designs for 30+ years. He claims to have raised well over $100m. He’s demonstrated a few quick “tethered flights”.

      But if he can just raise some additional funds he’ll also be in production by 2018 🙂

      1. Texas FFE says:

        Actually 40+ years. I visited the Mollier shop back in 1982. I’m not near as interested in VTOL as I used to be.

        I’m a lot more interested in affordable EVs and a fully developed national quick charging infrastructure. The propriety Tesla Supercharger network is not acceptable. I think CCS is the cornerstone of a fully developed charging infrastructure.

        1. RexxSee says:

          How many times do we have to repeat that Musk offered to share his network with other car makers ? And tell me who is better motivated in developing such a powerful network if not the only company who REALLY compete for the EV market? CCS at 50 kW is not fitted for the upcoming long range cars.

          1. Texas FFE says:

            I guess you need to keep repeating until Musk’s offer becomes acceptable to someone, anyone other than that Tesla. It’s not the Tesla technology that’s the problem, it’s that no one else uses it. Your opinion of CCS is irrelevant.

            1. Rick Danger says:

              As is your opinion of the Tesla Supercharger network.

            2. Goodbyegascar says:

              Why makes you think that Tesla needs to share their own (proprietary) charging network with anyone else?

              Tesla built it and paid for it so that their own customers can use it.

              What is so hard to understand?

            3. przemo_li says:

              CCS is 50 kWh.

              Nation wide highway would do more harm then help.

              Nation wide 100 kWh or even better 150 kWh on the other hand would be golden.

        2. Pushmi-Pullyu says:

          It gets very tiresome to see you keep repeating the entirely untrue, Tesla bashing mischaracterization of “proprietary” when talking about Tesla’s Supercharger system.

          Tesla has gone very far out of its way to try to get others to join its system, even to the point of offering a “free license” for all its patents. Just what else do you actually think Tesla should do to make its system even less “proprietary” than it currently is?

          Reality check: If the Supercharger system is “proprietary” it’s only because other EV makers don’t make BEVs with large enough battery packs to accept charging as fast as Superchargers are designed for.

          By that definition, any product which is significantly better than its competitors in any way, is “proprietary”.

          1. energymatters says:

            Could you please provide a link to the Tesla License Agreement Tesla provides for this access? Perhaps the GitHUB based (or other) “Open Source” source code and reference design files for AutoCAD or SOlidworks/OrCAD? The community forums and BoaF sessions typical of true open source efforts?

            1. Pushmi-Pullyu says:

              An official Tesla blog does refer to “the spirit of the open source movement” for its patents, but I don’t think that they have submitted the sort of formal declaration you refer to.


  6. Brian says:

    “To reduce noise and pollution, we are using electric engines so it can also be used close to urban areas.”

    aka don’t expect this thing to be in your backyard.

    This will be a toy for rich people and most likely get grounded when some moron flies it into a building or busy road and kills people.

    1. super390 says:

      Private plans are pretty much already playthings for rich people. And they seem to crash a lot.

  7. Apkungen says:


    1. mhpr262 says:


  8. Texas FFE says:

    Fast charging is at least as big a problem with electric aircraft as it is with electric land vehicles. If we can’t overcome the DCFC standard issue for land vehicles, how do we expect to charge electric aircraft? I’m afraid electric aircraft is going to have to wait for the next generation to develop.

    1. Fred says:

      You can all laugh as much as you like. If you do the maths, this aircraft makes sense. They need no more than 250wh/Kg to make it work.
      We have that at cell level. The “pack” structure can be part of the aircraft. No more than 50 Kwh required to achieve 500Km range at 300kph.

      Provided they have a light structure and good aero’s (all the fans are ducted, which makes them very efficient. And the fan/wing interaction can be used to their advantage. So a cruise L/D of about 17 is not too far fetched and should be enough to achieve performance.

      Entirely achievable project. Don’t even think unit price will be that expensive (150000$ is my guess).

      Watch this space!

      1. Ambulator says:

        My guess is $2,000,000 if they can bring it to production.

        1. Fred says:

          And what do you base your assumption of 2000000$ on?

          Provided the aircraft is produced in greater numbers, aircraft of this size and speed range have been constructed for less than 60000 dollars. That’s including everything! Avionics, instruments, engine, structure, flight controls, interior, etc, etc…

          Just guesstimating, but :

          Batteries : 50 Kwh @ 200$/Kwh = 10000$
          Motors, controllers, power electronics fans : 36 x 1000$/ unit = 36000$ (price of an average light aircraft piston engine. Call it 40000$ with all the cabling and interfaces.
          Structure, avionics, interfaces : 80000$

          About 130000$ would do the job. 200 000$ including devellopment costs.

          The additional devellopment costs per unit would depend on how many units are sold.

          The point I’m trying to make is that aircraft of this size and speed are already made. Because of current battery/motor technology, making it a VTOL doesn’t need to be that expensive.

          So 200000$ is still a lot of money. But I do see these aircraft could be used on a shared basis.
          They could be flown from small local heliports. Low noice signature would create minimal trouble with neighbours.

          The project makes sense to me.

          1. Ambulator says:

            I based my guess (not an assumption) on the current cost of aircraft, plus the fact that this is all new technology.

          2. super390 says:

            This is vastly more complicated than a Cessna. I’m doubtful about getting a complete motor, controller and fan for $1000. We’re dealing with composite everything here, and right now only companies like BMW have anything like the ability to mass-produce large composite structures. Finally, we have the sticking point that has kept VTOLs from becoming common, the dangerous transition to horizontal flight. Since the little high-pressure fans in this one act more like the vectored jet nozzles in the Harrier than the tilting rotors in the Osprey, I’m feeling pretty good about that part even though it surrenders the ability to autorotate.

            I’m really interested in the thrust to weight ratio. That’s a killer. With small fans you won’t get great thrust for the energy consumed, so you have to really hold down the weight. Helicopters and VTOLs burn so much fuel during takeoff that they actually weigh less afterwards, which helps them. Batteries don’t weigh less after suddenly getting 10-20% of their power sucked out of them.

    2. Pushmi-Pullyu says:

      Texas FFE

      “Fast charging is at least as big a problem with electric aircraft as it is with electric land vehicles.”

      If you compare the turnaround time it takes for “general aviation” aircraft operating out of a large public airport — and let’s remember that takeoffs and landings of general aviation aircraft are more common than for commercial jetliners — then I doubt the charging time is going to be an issue for potential buyers.

      As costly as this aircraft would be, if it ever actually entered production, it’s not going to be used for daily commuting by the average person. It’s going to be for the type of person who currently owns a helicopter and/or Lear jet for his/her personal use.

      1. super390 says:

        But if they’re going to pimp it as a “flying car” and try to raise billions for mass production, they’re going to claim you can fly it right out of your mansion. That sets expectations that you can treat it like a car. Which is not impossible once electric drivetrains are sufficiently reliable and national air-control networks are sufficiently idiot-proof. The latter will have to happen anyway because of all the future idiots operating bigger and faster drones. This level of national coordination is what NASA is associated with, so the interest by the European Space Agency may be significant.

        1. Pushmi-Pullyu says:

          This is a design (realistic or not) for a VTOL aircraft, and as such it’s better to compare it to a helicopter than a light plane. Plenty of rich people have helipads on private property. How would this be significantly different?

          The real difference is the suggestion that the plane would qualify as a “Light Sport Aircraft” in Europe, which I guess is similar to an “ultralight” rating in the USA… both of which require little or no pilot training.

          This doesn’t look to me like the type of ultralight plane which would cause little or no damage to structures if it fell on one. If this plane would indeed qualify for “Light Sport Aircraft”, then the rules for that need to be tightened up. But little danger of that actually happening, as this plane almost certainly will never be anything but vaporware.

          * * * * *

          I have no doubt that the day will come when a fully autonomous flying vehicle will be allowed to take off, fly to a destination, and land there, without having a licensed pilot aboard. But that won’t happen because of what this company is doing… or rather, wants us to believe it’s doing, but almost certainly isn’t.

  9. kalle says:

    their is electric vtol personal transporters that already flies tho, so not the first

    1. Fred says:

      Yes, the e-volo could be a nice helicopter. But speed and range would be disapointing.

  10. kalle says:

    and video

  11. SJC says:

    Something like this could be used for rescue evacuation to hospitals from a car crash.

  12. wavelet says:

    ROFL… Y’all realize someone decided to pull the ESA’s leg, right? Or did I miss the part where one could sign up for demo flights (-:

    That aside, anything airborne for personal transport is out of the question until the Earth population is back at around 2B. No room otherwise… 225sq.m. of flat area is a hell of a lot of land by any developed country’s standard except the US amd Australia.

  13. AlphaEdge says:

    I find it hard to believe this thing can fly.

  14. SJC says:


    I agree, not an air worthy design at all.

    1. arne-nl says:

      (Repeating myself)

      It’s more of a flying wing design I guess. The body creates the lift more so than the wings.

    2. Fred says:

      Please explain why it would not be airworthy?

      1. SJC says:

        It is trying to be a Rutan style canard, no way these scale dimensions work out.

      2. SJC says:

        Notice there are NO control surfaces, that means they intend to use thrust for control, which uses lots of power. They will use a LOT of their power doing VTOL, not much left for level flight nor control.

  15. DWL says:

    I think it must be a spoof. Centre of Gravity well forward of the main wing just doesn’t make any sense.

    1. mhpr262 says:

      Most likely the heaviest stuff (i.e. the battery pack, cooling systems and controller) will be in the back, plus the body itself appears to be designed to create lift. Normal aircraft looks and aesthetics don’t apply here.

  16. arne-nl says:

    Nicely rendered vaporware.

    1. Pushmi-Pullyu says:

      Yes, it’s a much prettier design than the Moller Skycar.

      And with the main wing that far back on the body, it’s a design even less likely to ever enter production.

      Real aircraft designs generate lift. That design appears to be designed to generate investment money, and nothing else.

  17. Anderlan says:

    Looking at the specs on their website, they’re impossible, unless they’ve a pack 1/3 the weight of Tesla’s or this thing flies at 15 miles/kwhr. Even then, of course, the range is wishful. Their specs are mutually exclusive, unless you go into the future for your parts.

    1. Fred says:

      Nope. 600Kg = (about) 6000N of lift required.
      Cruise speed L/D ratio could be as high as 17 (I’m assuming they have been very smart with the ducted fan placement and fan/wing aerodynamic interaction.)
      So thrust required would be about 350N.
      Speed is 300kph or bit more than 80mps.
      So power required is about 28Kw.
      In order to reach 500Km at 300 kph, thats 1,666… Hours at 28Kw = 48Kwh. Round it up to 50 Kwh for conversion inefficiencies.

      50Kwh of batteries would weight 50 000(wh)/250(wh/Kg) = 200 Kg at cell level. But you could use the wing and rear fuselage structure as the pack structure. So the pack part of the weight is part of the 200 or so kg of aircraft structure.
      Loads of cooling airflow available, so the cooling system could be kept light (small radiator or heat exchanger)

      So there you go. Pretty feasable if you ask me.

      1. Bone says:

        Can you name any existing two seater that can fly 300 km/h with less than 70 kW?

        500 km range at 130 – 150 km/h economy cruise speed would be remotely possible, but even that seems bit too optimistic and certainly doesn’t leave any reserve (any sane pilot would leave at least 30 minutes reserve).

        1. Doggydogworld says:

          Old VariEzes fly 300 kph at ~50 kW. They have (faired) landing gear, which this plan doesn’t.

          Fred’s 28 kW is optimistic, but with a canard instead of lifting body design it could probably get into the 30s.

          1. Bone says:

            I knew I should have limited my question to factory built type certified planes.

            Yeah, VariEze was insanely efficient, but it’s also much lighter and has in-line seating arrangement. I don’t think this design can be quite as efficient.

            1. SJC says:

              The specifications are misleading, you won’t get the range and speed after the power required for vertical take off much less the reserve power for vertical landing.

            2. Doggydogworld says:

              Yes, VariEze is lighter and tandem seating nelps. LongEze is a better match, but still tandem.

              Certified planes tend to be a lot heavier, so not comparable. In the US, Light Sport is limited to 222 kph, so again not comparable.

              SJC – the key would be to spend minimal time in hover. That said, I don’t see these little fans working. They look like 15 cm diameter, good for a few kg each vs. the ~20kg needed.

          2. Pushmi-Pullyu says:

            Good point about the Rutan VariEze having a main wing equally far back on the body, thanks. And it also has forward canards, just like this design.

            But the VariEze sailplane has a much larger wing in comparison to the overall size, giving it much better lift, which means it takes far less energy to keep it flying at its relatively low cruising speed of 165 MPH. This “Lithium Jet” is claimed to cruise at 210 MPH, with a much smaller wing. And I don’t buy the various claims here that it will get a lot of lift from a “lifting body” cabin shape. Some lift, yes. But I think not all that much; not nearly enough to make up for a much smaller wing area.

            Here’s a photo of the VariEze:


            1. Priusmaniac says:

              Since they start vertically and also receive the initial speed in that phase, it is possible that the lift from the small wing is just sufficient for the later higher speed flight. The VariEze must at contrary provide the full lift from the wing even at the low take-off speed and so need a larger wing. Add some small cabin lift and there you have the difference explaining the small wing size.

            2. Doggydogworld says:

              VariEze CG is much farther aft, at the rear seat (so CG doesn’t shift when you add a passenger). Part of the rear wing extends in front of the CG. You have to park these with the nose wheel retracted to keep them from tipping over backward.

              BTW, VariEze is not a sailplane and a larger wing takes MORE energy at high speed. Large wings are used to keep takeoff and landing speed low (a problem VTOL avoids). Also note Lilium is NOT a canard – the front nacelle retracts at speed. Finally, Lilium cruise is 186 mph (300 kph), not far off base VariEze. This VariEze got 45 mpg at 207 mph (~225 wh/mile):


              1. Priusmaniac says:

                So the 154 Wh/mile of Fred would be in line with the Lithium having not only electrofans instead of a propeller but in more have electrofan arrays at the trailing side at the wings. No vertical tail neither. This Lithium is going to make a serious revolution in airplanes. I hope the make a larger version seating five as well.

                1. SJC says:

                  Ducted fans have LOTS of drag in level flight at speed.

    2. Fred says:

      500km = 310mi/48Kwh = 6,5mi/Kwh.


  18. Pushmi-Pullyu says:

    The article says:

    “If such a plane were to become a viable offering, it would be easy to imagine how autonomous technology could quickly take over most of the operation.”

    The “Look, Ma, no driver1” videos posted of idiots intentionally defeating the safety features of the Tesla Model S, to allow AutoSteer (Beta) to drive the car even with no one in the passenger seat, leads me to advocate that anyone building an actual flying car intended to be operated by someone without a pilot’s license had better design the thing to make it as close as possible to physically impossible to operate without using full, 100% autonomous control, with no input from the passengers other than selecting a destination and selecting a suggested route.

    I shudder to think what would happen if there were thousands or even millions of flying cars all operating under the control of people with no better driving skills… even merely two-dimensional driving skills… than all too many American drivers display. (And I doubt it’s significantly better, on a per-capita basis, in most other countries.)

  19. Anon says:

    It makes me think of the movie, “Oblivion”…

    1. Priusmaniac says:

      Or this Yoko Tsuno craft (here)

  20. Dave says:

    Their web site says January 2018 and it’s June 2016, pretty much.

    As of this time all they have shown is CG renders.

    Don’t you think they’d have a physical mockup of the plane to show by now? Only 18 months from the “roll-out” of the plane?

    They’re not thinking about the complexities of every day living with a personal aeroplane. All their renders show ONE aircraft in the scene… not a bunch. And in fact no other aircraft of any type in the scenes.

    If it really comes out, great. But I have to be skeptical that it will have a range of 300 miles, or even take off. The payload is pretty small.

    It’s a struggle to get an electric car to roll along the ground for 30 miles right now. For them to say they can fly a plane through the air for that distance… seems like a stretch.

    I think has given this plane about as much coverage as it deserves… and shouldn’t give it any more publicity until they show an actual prototype that flies.

    1. SJC says:

      It would be more convincing if they published simulation result as evidence that it flies as rendered.

  21. Priusmaniac says:

    The fans above the wing are going to reduce the pressure there further giving more lift.
    The fans need to give 20 Kg each, that is a lot of power at take-off and likely a lot of noise too.
    On the other hand they are electrofans so quieter than turbofans.
    The canard in front enter the cabin space, that is a bit to bad.
    They probably had enough space anyway and figured out that retracting these after take-off would be beneficial to energy efficiency.
    No vertical stabilizer is also beneficial to energy efficiency.
    You know what? I think I start to like this craft. It is really very well though off and deserves an honest congratulation.

  22. Priusmaniac says:

    If the E-fan specs are an indication each of those electrofans produce 750 N from 30 KW, so a 200 N requirement would mean 8 KW. 36 of those give 288 KW. Adding some spare for controls and auxiliaries, plus some inefficiency associated with a smaller electrofan diameter and the 320 KW total power indeed start to make sense.

    1. SJC says:

      Notice the SIZE of the airbus fans, this is not what they illustrate. I published a link for a thrust calculator which was blocked, but they have NO way of creating the required thrust for vertical takeoff.

      1. Jay Cole says:

        Hey SJC,

        No idea why our filter didn’t like your link…but I dug it out of purgatory for you, (=

        1. SJC says:

          Thanks Jay, I have all the recommended settings on my browser, so it should have gone through.

          The battery weight seems to be the limiting factor for vertical takeoff with 250 mile range. 250 mile range can not be done.

          After you fly the pack state of charge will be low, you still need about 200 kW to land, you may not have that much POWER left. If a 100 kW pack is 90% depleted it does not want to deliver 200 kW of power with only 10 kWh of energy left.

          1. Priusmaniac says:

            If a 100 KWh pack in a Tesla (supposing that upgrade was made available) was depleted with 10 KWh left, it would still be able to deliver 200 KW for an acceleration, not for long but power and state of charge does not correlate in a linear way. I suspect there is a reduction curve in peak power but not such a strong one. Perhaps they also use a different type of battery with emphasis on peak power for short peak use, they can also resort to power electronics using buffer capacitors to deliver temporary peaks. It will be interesting to find out.

        2. Priusmaniac says:

          This calculator appears to be for propellers. A ducted fan is an entirely different situation with no leak on the rim more blades and higher pressures. Perhaps a Dassault ducted fan calculator could be used but that won’t be easy to find, in more there is interference from the reactor core. That is why I looked up at the closest existing thing for a reference which is the E-fan electrofans.

          1. SJC says:

            Have at it guys, come up with a ducted fan static thrust calculator, most of them are for RC aircraft.

            One example for a larger fan is:

            40″ diameter at 2400 RPM produces 194 pounds of thrust. (I would post the link but the whole message could be blocked)

            If you use the propeller calculator with 4 blades and assume the ducted fan has 8 blades, you can approximate by multiplying by two to get 150 pounds of thrust.

            This craft does not have 40 inch fans, they might be 10″, if you run that at 9600 rpm you get about 10 pounds of thrust. Even if you could get 20 pounds of thrust with a 12″ fan times 36 fans that is 720 pounds of thrust, far short of lifting a 1400 pound craft.

        3. Bone says:

          Calculator made for open air propellers is not suitable for ducted fans. A ducted fan needs less diameter to create same static thrust as propeller.

          1. SJC says:

            How much smaller diameter? If you come up with a ducted fan calculator, let us know.

  23. Priusmaniac says:

    There is however one thing they will have to deal with beyond range anxiety, it the landing anxiety. Indeed if they use a burst of 320 KW for the take-off, they also have to give that burst at the landing. If they already did 500 km the battery will be close to empty exactly at the precise moment they need to give that landing 320 KW power burst. If they don’t they are not merely on the side of the road but they crash on the ground. They will have to put serious software on board to make sure never to run on an empty battery and always keep the equivalent of at least a landing in energy. An autopilot could calculate and take care of that with some spare but that will be an absolute must have. Perhaps it would be safe to add an emergency parachute on top the craft, just in case the battery breaks down.

    Another concern is icing. What happens when ice get on the wings and bits break off and go directly into the electrofans? Again avoiding icing will be imperative.

    1. SJC says:

      Even with a 100 kWh battery, there is NO way they can take off vertically, go 250 mph for 250 miles and land vertically. That pack would weigh more than a 1000 pounds, the maximum takeoff weight is rated at under 1400 pounds.

      This is why I say the specs are misleading, you may be able to do one or the other but not all of them on one charge.

      The Airbus craft is horizontal takeoff and landing, it require two LARGE thrust producers. If you look up a thrust calculator for many smaller fans you will see they can not do it, even at very high RPM..

      1. Doggydogworld says:

        The spec is 310 miles at 186 mph. An efficient plane this size can do that in ~60 kWh. VTOL to 100m plus transition to ~180 kph is ~2 MJ or a bit over half a kWh. Assuming 80 kW is available for climb/accel (240 kW for hover) you need less than 30 seconds from lift off to transition. That uses less than 3 kWh. Landing is similar, so total energy usage is 66 kWh. That’s 330 Wh/kg and 1600 W/kg, well beyond Tesla cells but not impossible.

        The big problems here are:
        1. Tiny fans are inefficient and produce too little thrust
        2. Body lift is grossly inefficient
        3. Lose electricity (short, lighting strike) and you lose control and the ability to land

        Fix #2 with a canard and #3 with a chute + insurance policy (e.g. Cirrus SR22). I don’t see how you fix #1.

        1. SJC says:

          310 mile range at 186 mph is 100 minutes of flight time. It takes about 130 hp for a small craft to sustain 186 miles per hour or about 100 kW for more than 1 1/2 hours, you don’t have 150 kWh of battery, that would be more than 1400 pounds, which is the maximum takeoff weight of the plane.

          1. Priusmaniac says:

            Probably an underestimation in the efficiency increase from going from a propeller aircraft to an electrofan array aircraft. The lifting body cabin and the absence of drag from a vertical stabilizer also do make a difference. All bits together can add up to a big final difference.

            1. SJC says:

              Unless those factors are quantified it may not be accurate to state they will make a big difference.

          2. Doggydogworld says:

            Again, clean designs like the VariEze can do 186 mph on 50 kW, no 100 (see my Wired link above on 45 mpg at 207 mph). An updated design with no landing gear, engine cooling airflow, etc. could do a bit better.

            1. SJC says:

              VariEz is a one passenger aircraft with a small cross section and less drag.

              1. Doggydogworld says:

                As discussed above, they’re tandem two seaters. A little more efficient than side x side, but IMHO modern CFD and electric’s advantages would compensate.

                I’m sure these guys ran basic parametrics. But that’s probably about it, and the devil is always in the details. But it’s not like they’re off by a factor of three or anything.

                1. SJC says:

                  A VariEze has half the cross section of a side by side two passenger like a Cozy. The extra weight and drag require more power for a given speed.

                  1. Doggydogworld says:

                    Tandem width is more like 60% of side x side. But tandem Cd is higher as cross section is less circular, taper is more abrupt, engine hangs out in the flow (see “bumps” at rear of VariEze), etc.

                    The Quickie Q2 is an example of a side x side which did 180 mph on 47 kW. With a tractor prop, no less. It’s lighter, so not a perfect comp, but again a VTOL with a high speed wing and no landing gear could be much cleaner.

                    The bigger drag issue is the fan ducts, as you noted upthread. Especially with square ducts. I doubt they have good numbers for that.

                    1. SJC says:

                      Cozy Cabin front W/H 42/39

                      Vari-Eze Cabin front W/H 35/23

                      It is more than 60% total cross section area, which determines drag and power required.

                    2. SJC says:

                      Typo correction:

                      Vari-Eze Cabin front W/H 23/35

      2. Priusmaniac says:

        Perhaps we can check in another way. If we suppose 20 kg of thrust per electrofan and a 10 cm radius making a section of 314 cm2, that would demand that the fan create a pressure difference of 64 mbar. That kind of pressure differential doesn’t seem to be out of reach. In more they have at least two backup solutions. One by double the fan in each electrofan. Two by increasing the diameter up to the point where they find a match between thrust required and diameter.

        1. Doggydogworld says:

          10 cm radius would be 22 cm outside diameter. These fans aren’t that big. Maybe 15 cm outside diameter. At 22 your wing would be longer, front nacelle would be too big, etc.

          Here’s a 12 cm fan that does 95 N on 5.7 kW, though. Size that up to 17 cm for 200 N on 11kW? So maybe not as impossible as I thought….

          1. Priusmaniac says:

            Very interesting. It seems you indicated exactly what is needed.

          2. Priusmaniac says:

            Apparently what is needed is already coming it is called the Schübeler DS-215-DIA HST and gives a thrust of 240 N. That is more than what’s needed.
            Here is a link to a page in German but the numbers and pictures speak English:


            There is also a video below.

            1. SJC says:

              Speed range: 22,000 – 38,000rpm

              You need to link the fans in case of failure.

            2. Doggydogworld says:

              240 N is borderline. 240 in the test stand is ~220 installed. Hot day in Denver degrades you another 20% or so, meaning you can barely hover. A wind gust could slam you on the ground and you don’t have enough excess thrust to climb and accelerate to transition.

              A fixed pitch fan normally won’t do well from 0-400 kph, but with static flow velocity of ~100 m/s may this one would work. Power is almost double Lilium’s goal, though (16.7 kW * 36 = ~600 kW). On the other hand, 2.7 kg for fan + motor is great.

              I’m very impressed with this little fan – good find.

              1. SJC says:

                One site said:

                “Lilium is a small body aircraft, powered by two electric motors…”

                If this is true they are linked, but 20,000 rpm would make that difficult.

                1. SJC says:

                  Inhabitatn showed a view of the fan, each has its own motor. If one of the six fails on one side of the nose, the others have to rev up to make up for the loss.

              2. SJC says:

                The bigger fuselage cross section with the drag of 36 ducted fans would make the 248 mph maximum speed unlikely.
                The range is unlikely for the same reasons with a 50 kWh pack, which is about the maximum for a plane with a 200 kg takeoff weight.

                1. Doggydogworld says:

                  In cruise it’s 24 ducted fans, not 36. Still draggy.

                  You mentioned the Cozy 4-seater. It does 185 mph at 40% power (54 kW) with fixed main gear. I have little doubt a 2-seater without gear could get close to 40 kW. You only need a few fans for cruise. They should be unducted and all the ducted ones should hide themselves at speed.

                  1. SJC says:

                    The 24 fans are all ducted for level flight, so they produce significant drag. No matter how you calculate it the battery pack has limited capacity due to weight. They will not be able to do 248 miles per hour NOR have a range of 300 miles with today’s technology.

  24. Doggydogworld says:

    I agree this plane won’t perform as advertised. 24 tiny fan ducts have too much drag. 36 fans this size (~15 cm) won’t generate enough thrust. 20 cm fans could, but the power draw is twice what they say. Finally, it needs a canard.

    The Airbus E-Fan 2.0 is a great cruise comp. Near-identical body and 600 kg weight, yet it only gets to 220 kph on 60 kW. Why 80 kph slower than the heavier Cozy at similar power settings? The E-Fan is a trainer, with a large and docile (but inefficient) wing. But the fan ducts also hurt a lot. And Lilium’s tiny ducts are much worse.

    At first I laughed at the concept. After running some numbers I realized the concept works, at least with next-gen batteries. It just doesn’t work the way they drew it.

  25. Doggydogworld says:

    BTW, Google “Basics of Electric Ducted Fans” for a PDF with some good basic info and helpful charts. The third chart shows why tiny fans use so much more power to produce a given amount of thrust.