Lilium eVTOL Jet flying above a field, October 22, 2019, Germany.

Lilium Jet
Lilium GmbH
Wessling, Germany
www.lilium.com

Lilium GmbH is a Germany-based start-up co-founded in 2015 by four aerospace engineers and product designers — Daniel Wiegand, Sebastian Born, Patrick Nathen and Matthias Meiner — all from the Technical University of Munich (Wessling is a municipality located near Munich, Germany).

Financing

Initially, the company received funding from the European Space Agency and the European Union’s Climate-KIC program, Europe’s largest public-private innovation partnership focused on climate innovation to mitigate and adapt to climate change.  By Sep. 2017, Lilium raised more than $100 million for the company and in Oct. 2019 it as been said they are seeking to raise between $400 to $500 million more in financing.

Early Prototypes

Wiegand originally conceived the basic electric Vertical and Take-Off and Landing (eVTOL) jet concept in 2013. There were four (4) sub-scale prototypes named the Gleiter, Hexa, Dragon and Falcon. Then a full-scale two (2) seat “Eagle” prototype was created and completed a series of unmanned test flights in April 2017. Following the successful test flights of the Eagle proptotype, Lilium moved forward with a five (5) seat full-scale production model.

Five (5) Seat eVTOL Lilium Jet

On May 16, 2019, Lilium revealed they had announced its first flight of an untethered and unmanned five (5) seater Lilium Jet which took place on May 4, 2019 at the Special Airport Oberpfaffenhofen airport in Munich, Germany. Extensive ground testing took place before its maiden flight. The full-scale prototype is powered by 36 all-electric ducted fans which allows for a vertical take-off and landing with an efficient horizontal flight.

In its Oct. 22, 2019 press release, Lilium describes its aircraft as “the world’s first five-seater, all-electric, vertical take-off and landing jet.” The company plans to manufacture the aircraft and manage aerial ride-sharing for urban and regional air mobility as an air taxi. The company will not be selling these aircraft.

In cruise mode, the power consumption per km is comparable to an electric car. It produces zero emissions in flight and the aircraft is being certified as a fixed-wing aircraft. The aircraft is six (6) to seven (7) times quieter than a helicopter at take-off. Not only are their electric motors quieter than combustion engines but Lilium has developed a duct to adsorb as much noise as possible from the electric motors. Each engine is individually shielded so the failure of a single unit cannot affect the adjacent engines. The foreward canard will not be retractable.

It will be easily piloted (requiring a Sport Pilot’s License) and Lilium’s Flight Envelope Protection System will prevent a pilot from performing maneuvers that would exceed the aircraft’s flight parameters. The company at first, plans on having their aircraft piloted for aerial ride-sharing and in the future their aircraft will fly in autonomous mode.

Having 36 engines makes the Lilium Jet more efficient, safer and more maneuverable.

The increase in efficiency stems from integrating the engines into the wings. The engine nacelles are part of the wing and help create lift. This means we can reduce the surface of the wing and the associated drag, which is the friction generated when moving through air. Having more engines also allows you to distribute the power along the wing, generating further efficiency.

The increase in safety comes from redundancy. With 36 independent engines, we’re well covered in the very unlikely case that an engine fails.

Last but not least the manoeuvrability of an aircraft increases if you use smaller engines. The time taken to increase power (‘spin up’) or decrease power (‘spin down’) in a small engine is much less than that in a typical aircraft engine, meaning the Lilium Jet is able to respond much more rapidly to a control input. In fact, in the case of our own electric engines, which we’ve developed in house, they are capable of ‘spinning up’ from zero thrust to maximum thrust in less than one second!

Lilium blog article, May 15, 2019

Since its maiden flight, featuring a simple vertical take-off and landing, the aircraft has been undertaking increasingly complex maneuvers and longer flights. Having successfully completed more than 100 different ground and flight tests, the first phase of testing culminated with a flight that saw the aircraft travel at speeds exceeding 100 km/h (62 mph) and have seen the aircraft turn at bank angles of up to 30 degrees and climb and descend vertically at rates of 152 m (500 ft) per minute.

During the first phase of testing, the aircraft also successfully completed a range of safety tests, including engine failures and flap failures, as well as fuse-blow-tests on the ground and in the air. Following a test flight, the aircraft returns to the hangar for charging while their engineering teams analyze the significant amount of data that is generated from more than 9,000 parameters on each flight.

Lilium has four (4) teams who work together on flight testing – flight test engineers, pilots, a flight test instrumentation team and flight test maintenance engineers. They are supported by their systems engineering and software development teams. It takes about 40 people in total to perform a test flight. The aircraft, which is controlled remotely from the ground, will now move on to its second phase of testing which will look specifically at how it performs at high speeds.

The new footage reveals, for the first time, the aircraft transitioning from vertical flight to level flight. This signature maneuver, first completed just weeks after the aircraft’s maiden flight, is one of aerospace’s greatest challenges and is what gives the Lilium Jet its significant range advantage, with its two sets of wings contributing to much higher levels of efficiency than in aircraft lifted solely by rotors.

Lilium press release, Oct. 22, 2019

About Simplicity and its Importance in the Lilium Jet Aircraft Design

Simplicity is one of the key design elements for Lilium. There are many things you can leave out of an aircraft to keep complexity to a minimum which translates into lower manufacturing costs, lower maintenance costs, greater safety (less things can fail), greater affordability, less weight and increases efficiency. The company stated that every component that is not there, does not have to developed and does not need to be maintained. Listed below are a few items about the importance of simplicity of the Lilium Jet eVTOL aircraft.

  • No folding propellers or wings
  • No tail
  • No rudder
  • No propellers
  • No gearboxes
  • No variable pitch
  • No water cooling
  • No liquids (petroleum fuel or oil)
  • No single point of failure. (If an aircraft has one [1] engine and if it fails, that is a single point of failure.)
  • Wings provide greater efficiency for forward flight
  • Each electric motor has one moving part
  • 36 ducted fans provide ultra-redundancy

With a top speed of 300 km/h (186 mph) and a range of 300 km (186 m), the Lilium Jet is capable of completing much longer journeys than the majority of its competitors. This is, in part, is due to the fixed-wing design of the aircraft. While multicopter-based aircraft consume much of their energy keeping an aircraft in the air, the Lilium Jet can rely on the lift generated by the fixed-wing to do this, meaning it will require less than 10 percent of its maximum 2,000 horsepower when it reaches its cruise flight.

These pictures below, taken on Oct. 10, 2019, reveal a second model for the Lilium Jet. In the middle picture, it appears the first version is in the background and the newer model is in the foreground.

When we designed the Lilium Jet we looked at more than 20 existing aircraft concepts but soon realized that none of them would deliver what we wanted. We were searching for levels of efficiency that were close to the limits of physics, delivered in the most simple way.

So instead of tweaking an existing design, we chose to design something from scratch. The result is the Lilium Jet which has no tail, no rudder, no oil circuits, no gearboxes, no variable pitch fan blades and only one moving part in the engines.

Our philosophy has always been that simplicity is key: it makes the aircraft more robust, it makes it safer, it makes it easier to maintain and it lowers the cost to certify, manufacture and operate the aircraft.

Lilium blog article, May 15, 2019

Smart Factory

The company also has also begun a second and much larger smart manufacturing facility, compared to its original 3,000 square meter facility, for the serial production of the Lilium Jet. Their manufacturing facilities are clean-sheet designs using 3-D technology, allowing all involved to see and make recommendations on the design of the factories. Simulations are being performed to see how the supply chain responds to failures and unforeseen events.

The manufacturing plants will be smart factories and scalable to multiple sizes, be digitally-native from the start and use adaptive work instructions. This approach to their manufacturing plants is being done to achieve higher volumes of production than current aviation industry plants produce. Lilium’s aim is to produce hundreds of aircraft each year by the time commercial services begin.

Future

Lilium plans to both manufacture the Lilium Jet and operate the Lilium Jet as a point-to-point on-demand regional air taxi service where its passengers would be flying within an urban area, within rural areas, from urban to rural areas or from city to city, and increase your Radius of Life – the area in which we our day-to-day life. Lilium states with their aerial ride-sharing operations, a person can increase your Radius of Life by a factor of 25. On-demand air transportation.

As of October 2019, the next flying goal for Lilium is approximately one year of high-speed flight testing. Flight testing will continue to be remotely piloted to remove the risk of any pilots dying during an unsuccessful test flight. On Jun. 11, 2019 Lilium stated that it had selected London to be “the base for a world-class software team it plans to develop.” Hundreds of high-end software engineering roles will be created in the city over the next five years as the business seeks to make affordable, electric, on-demand air taxis a reality by 2025. 

The company has stated they will create landing pads or Lili pads on the top of buildings and other areas, and that minimal infrastructure is needed for their Lili pads. The cost of their on-demand aerial ride-sharing will be the similar to the price of taking a taxi. In fact, they have done several price studies and the price for flying in certain cases is shown to be less than the cost of road vehicle taxi. The company predicts that their aerial ride-sharing will be 17 times the amount revenue compared to its road vehicle ride-sharing cousin.The company wants their air service to be affordable and accessible to everyone and not for the select few.

The company has stated that the Lilium Jet will not be for sale to the consumer, this was decided early on when the company was formed. Lilium expects to be fully-operational in various cities around the world by 2025, although trial services will start earlier than this in several locations. As of October 2019, Lilium employs more than 350 people, are now hiring more than 150 people and are expected to hire up to 500 new people between now and 2015.

Specifications:

  • Aircraft: eVTOL Jet
  • Piloting: Aircraft will be piloted and in the future will be autonomous
  • Capacity: 5 passengers
  • Cruising speed: 186 km/h (186 mph)
  • Range: 300 km (186 m)
  • Maximum flight time: 60 minutes
  • Propulsion: 36 electric ducted fans and 36 electric motors. The electric ducted fans are located in pairs of three (3) in the wings for a total of twelve (12) fan units or flaps. There are two (2) flaps on each forward wing and four (4) flaps on each rear wing. Each flap can tilt independently of one another and operate at different speeds of each other, based on wind conditions during vertical flight, transitioning between vertical and forward flight, and during forward flight which provides an extremely stable and safe flight.
  • Ducted fan technology type: Officially, the company is not commenting on any technology they are using
  • Power: Batteries
  • Battery type: Officially, the company is not commenting on any technology they are using
  • Wing configuration: Canard wings
  • Interior: The interior is spacious and will be made to maximize the passenger’s experience. Lilium has reported that seating will change its shape to fit the person, the canopy can become a screen to make flying more enjoyable and passengers will use an app to schedule a flight.
  • Windows: Excellent view above, left, right and forward due to the dome shaped window
  • Doors: Gull-wing
  • Landing gear: Tricycle landing gear with wheels
  • Airframe: Composite
  • Safety: Ultra-redundancy with 36 electric ducted fans, 36 electric motors and a triple-redundant flight control computer. A small fan can respond much more quickly than a large fan and therefore the aircraft can respond much more rapidly to any control input.
  • Emergency safety system: Whole aircraft parachute
  • Noise: 6 to 7 times quieter than a helicopter at take off
  • Certification of aircraft: Fixed-wing
  • Lilium landing pad name: Lili pad

Resources

Videos:

Tags:

LiliumVectored ThrustFlight Testing2 PassengersElectric/BatteriesAutonomousVFS Member