| Lilium Jet | |
|---|---|
.jpg)
| |
| Lilium Jet cabin demonstrator | |
| Role | eVTOL |
| National origin | Germany |
| Manufacturer | Lilium GmbH |
| Status | Under development |
The Lilium Jet is a prototype German electric vertical take-off and landing (eVTOL) electrically powered airplane designed by Lilium GmbH.[1] A seven-seat production version is planned.[2]
Initial design studies included forward-folding wings, so that the aircraft could be piloted as a VTOL and recharge in only few hours from a standard 240 V electrical outlet. A first half-scale demonstrator, Falcon, flew in 2015. The unmanned first flight of the two-seat Eagle full size prototype was on 20 April 2017 at the Mindelheim-Mattsies airfield, Bavaria, Germany.[3]
Unmanned flight testing of the five-seat Lilium Jet took place at Oberpfaffenhofen airfield near Munich. It first flew in May 2019.[4][5] By October 2019, after 100 flights, it could transition from vertical to horizontal flight, reaching over 100 km/h (54 kn), but not yet fully horizontal. It managed 25° banked turns, high ascent/descent rates like in operations, hover turns and sideward translations. Electrical, fan and flap failures were mitigated by the electrical and flight control systems.
The first prototype was destroyed by fire during maintenance on 27 February 2020. A second partially-constructed prototype was undamaged.[6] A further unfinished prototype was abandoned, and work begun on a seven-seat version.[7]
The Lilium Jet uses multiple relatively small ducted propellers driven by electric motors to provide lift during take-off and landing, as well as thrust during the cruise phase. Lilium says that it refers to the propulsion system as a "jet" because the propellers are enclosed in nacelles.[8] The production Lilium Jet is intended to accommodate six passengers and one pilot. It is powered by 36 electric motors, six on each of the two front canards and twelve on each rear wing. The motors are installed above twelve tiltable rear flaps. The drive-carrying flaps pivot downwards for vertical launch.[9] At the transition to the horizontal position, forward thrust is generated. This is claimed to be significantly more economical than a conventional rotorcraft, however the propulsion configuration generates very high disc loading and power-delivery requirements significantly exceeding the leading competitive eVTOL designs.[10]
Lilium invested in Ionblox for its silicon-dominant anode battery technology, which it believes offers uniquely high energy and power density (12C with 3.8 kW/kG at 50% charge and 3.0 kW/kG at 30%) needed for hover and take-off phases, even at low charge levels.[11]
The target range is 280 km (150 nmi). Its 36 electric ducted fans are powered by a 1 MW (1,300 hp) lithium-ion battery; less than 200 hp (150 kW) is required to cruise.[12]
Data from Lilium GmbH / Electric VTOL News by the Vertical Flight Society[13]
General characteristics
Performance
The Lilium GmbH plans to found an air taxi service for urban air mobility and Advanced Air Mobility with the Lilium Jet.[14] The company expects that pilots will be needed for around 10 years until autonomous flights can take over.[12]
In October 2019 the Lilium five-seater Jet received a Red Dot Award: Design Concept for “Best of the Best”.[15]