Lilium has started assembling the electric propulsion system (EPS) it has developed for its six-seat eVTOL aircraft. The German company reported the milestone on September 26, a week after announcing that its partner Aciturri is building the first fuselage for one of seven Lilium Jet prototypes with which it intends to begin crewed test flights in late 2024.
The distinctive EPS design is based on 30 ducted-fan electric engines installed in the aircraft’s wings and canard. In the first phase of assembly, rotating parts—such as the shaft, magnets, and titanium compressor fan—are built and then mated with static components, including the electric motor stator and the guide vanes used for structural support and cooling.
These subsystems will then be combined with the electric engines, which later this year will be integrated with the Lilium Jet’s propulsion mounting system. The mounting system consists of flaps that form the rear part of the wings and front canard, housing both the propulsion and vectoring units that support vertical and horizontal flight.
While Lilium has designed the EPS itself and is the system integrator, it has had significant support from key partners. These include U.S. aerospace group Honeywell and Japan’s Denso, which worked together to develop the electric motors. Aerononamic has provided the titanium compressor fan, with SKF supplying electric motor bearings.
In July, Lilium completed tests on a full-size prototype of the fan and stator subsystem using the Jetpel test facilities in Germany. The company has also started testing a prototype electric motor to assess its mechanical, electrical, and thermal performance. Weighing only four kilograms (just under nine pounds), this motor is expected to deliver a power density of over 100 kilowatts.
“For my fellow co-founders and myself, the start of industrial assembly of the Lilium Jet propulsion unit marks a special moment,” commented Daniel Wiegand, chief engineer for innovation and future programs. “It was our shared belief in the radical potential of our electric jet technology that formed the nucleus of our company and that has driven Lilium forward ever since. I’m more convinced than ever that our vision of a sustainable new form of high-speed and affordable regional transportation will become a commercial reality."
Since Wiegand and colleagues founded the Munich-area-based company back in 2015, it has tested five generations of technology demonstrators. Today the company employs more than 800 people, including around 450 aerospace engineers.
According to Lilium, its eVTOL vehicle is expected to have a maximum "physical range" of 155 miles and an "operating range at launch" of 109 miles, with a cruise speed of 155 mph. The company aims to complete type certification with EASA and FAA by the end of 2025, with the first deliveries to customers set to start in 2026.
