Lilium Jet
The Lilium Jet is a prototype electric vertical take-off and landing (eVTOL) aircraft developed by Lilium GmbH, a German aerospace company founded in 2015, designed primarily for sustainable regional air mobility with capacity for up to six passengers and one pilot.[1] It employs a novel propulsion system consisting of 30 battery-powered ducted electric fans distributed across tilting flaps in its canards and main wings, enabling vertical takeoff, hovering, and efficient forward flight at jet-like speeds while producing significantly lower noise levels than traditional helicopters.[2] Intended to decarbonize short-haul aviation, the aircraft targets intercity routes of 100–300 kilometers (62–186 miles), with a cruise speed of approximately 280 kilometers per hour (174 miles per hour), a maximum range of around 250 kilometers (155 miles) on a single charge, and the ability to operate from existing heliports due to its compact 13.7-meter (45-foot) wingspan and under-14-meter dynamic footprint.[3] Zero operating emissions and a focus on passenger comfort, including a spacious pressurized cabin, position it as a versatile platform for urban and regional transport.[1] Development of the Lilium Jet began with early subscale demonstrators, culminating in the first full-scale prototype's maiden flight in May 2019, during which it achieved transition from vertical to horizontal flight and speeds exceeding 100 kilometers per hour (62 miles per hour).[4] Subsequent milestones included over 100 test flights by late 2019, the powering on of the first production-intent aircraft (MSN 1) in October 2024, and progress toward certification under European Union Aviation Safety Agency (EASA) special condition for VTOL (SC-VTOL) rules, with Design Organization Approval granted in November 2023 and a G-1 certification basis issued by the U.S. Federal Aviation Administration in June 2023 to support dual global certification.[5][6] Lilium targeted type certification by late 2025 and entry into service in 2026, with initial production plans for 25 units in 2023 scaling to hundreds annually, backed by partnerships with entities like Honeywell for avionics and airlines such as NetJets and Azul for commercialization.[7][8] However, manned flight testing was delayed to early 2025 amid supply chain and funding challenges.[7] The Lilium Jet's technical innovations include high-voltage battery packs integrated into the wings for optimal weight distribution, redundant flight controls for safety, and a vectored thrust system that redirects airflow for seamless mode transitions without exposed rotors, enhancing urban acceptability.[2] Its maximum takeoff weight is approximately 3,175 kilograms (7,000 pounds), with a service ceiling of 3,000 meters (9,800 feet), and it was designed for rapid recharging in under an hour to support high-utilization operations.[9] Lilium's approach emphasized scalability, with the platform adaptable for cargo or medical evacuation variants, and it pursued infrastructure collaborations for vertiports and charging networks.[1] Despite these advancements, Lilium GmbH filed for insolvency in February 2025—the company's second such proceeding—after failing to secure promised funding, leading to the cessation of operations and the abandonment of the Lilium Jet program before achieving full certification or production.[10] In October 2025, U.S.-based eVTOL developer Archer Aviation acquired Lilium's extensive patent portfolio, including over 300 intellectual properties related to the Jet's ducted fan and battery technologies, for €18 million, preserving elements of the innovation for potential future applications in the advanced air mobility sector.[11] This outcome underscores the financial risks in eVTOL development, though the Lilium Jet remains a notable example of ambitious electric aviation engineering.[12]Development
Founding and early concepts
Lilium GmbH was founded in 2015 in Munich, Germany, by four alumni of the Technical University of Munich (TUM): Daniel Wiegand, Sebastian Born, Patrick Nathen, and Matthias Meiner. All four were engineers and students at TUM during the company's inception, driven by a vision to pioneer sustainable urban air mobility through all-electric vertical take-off and landing (eVTOL) aircraft. The initial focus centered on innovative electric ducted fan propulsion systems to enable quiet, efficient VTOL operations without relying on traditional rotor tilting mechanisms.[13][14] In 2016, Lilium advanced its early concepts by developing subscale demonstrators to validate core technologies, including the half-scale Falcon model—which achieved its first flight that year—and the Dragon subscale prototype. These models emphasized distributed electric propulsion (DEP), integrating multiple small ducted fans across wing structures to distribute thrust for enhanced stability and efficiency in VTOL configurations. The designs drew from initial two-seater concepts, scaling up propulsion elements to test feasibility for personal air mobility. A pivotal innovation in these early efforts was embedding ducted fans directly into movable wing flaps, enabling seamless transition from vertical hover to forward cruise by deflecting the flaps to redirect airflow—eliminating the mechanical complexity and weight of tilting rotors or nacelles common in other eVTOL designs. This approach prioritized aerodynamic efficiency and reduced noise, aligning with the company's goal of jet-like performance in an electric framework.[15][16][17] To support these foundational developments, Lilium secured initial funding through a seed investment from Freigeist (formerly e42) in 2015, followed by a €10 million Series A round in December 2016 led by Atomico. The company then raised a $90 million (approximately €76 million) Series B round in September 2017, led by Atomico with participation from investors including Hunch Ventures, LGT, and H&Q Asia Pacific, bringing total capital raised to over $100 million and enabling progression toward full-scale prototypes.[18][19]Prototyping and flight testing
Lilium's prototyping efforts began with subscale models to validate core technologies before advancing to full-scale demonstrators. In April 2017, the company conducted the first untethered flight of its two-seater Eagle prototype at the Mindelheim-Mattsies airfield in Bavaria, Germany. This unmanned test demonstrated stable hover capabilities and a successful transition to forward flight, marking a key early milestone in electric vertical takeoff and landing (eVTOL) development.[20][21] Progressing to full-scale testing, Lilium unveiled its five-seater prototype in May 2019, achieving the maiden untethered and unmanned flight on May 4 at Oberpfaffenhofen airfield near Munich, Germany. This demonstrator, powered by 36 electric ducted fans, focused on validating vertical takeoff, hover stability, and initial transition maneuvers. By October 2019, the prototype had completed over 100 flights, including vertical-to-horizontal transitions at speeds exceeding 100 km/h, confirming the aircraft's aerodynamic and control system performance under real-world conditions.[22][20][23] In 2021, Lilium introduced the Phoenix 2 technology demonstrator as part of its seventh-generation development toward the production 7-seater Lilium Jet, emphasizing advanced flight envelope expansion. This full-scale, unmanned aircraft underwent extensive ground and flight testing starting in 2022 at the ATLAS Flight Test Center in Spain. Key achievements included the first main wing transition from hover to wing-borne forward flight in June 2022, followed by full transition on both wings and canards in September 2022, demonstrating precise control across flight regimes.[24][25][26] Testing continued into 2023, with Phoenix 2 reaching a speed milestone of 136 knots (approximately 250 km/h) in forward flight during a March test at ATLAS, validating the targeted cruise performance and structural integrity at high speeds. These flights provided critical data on propulsion efficiency, stability, and energy management, advancing the design toward certification requirements.[27][28] Culminating pre-production efforts, on October 1, 2024, Lilium achieved a successful systems power-on for the first production-intent airframe, designated MSN 1, at its facilities near Munich. This test applied 900 volts to the integrated high-voltage architecture, successfully powering onboard systems including batteries, power distribution, and flight controls, thereby confirming electrical integration and safety protocols ahead of ground testing.[29][3]Certification and production plans
Lilium engaged closely with the European Union Aviation Safety Agency (EASA) to advance the regulatory approval of its seven-seater Lilium Jet eVTOL aircraft. In November 2023, the company received Design Organization Approval (DOA) from EASA, establishing it as qualified to design and hold a type certificate for aircraft developed under the agency's Special Condition for Vertical Take-Off (SC-VTOL) rules.[5] This milestone enabled Lilium to self-certify aspects of the design process, streamlining progress toward full type certification. The firm targeted EASA type certification in late 2025, with entry into service planned for 2026 following a rigorous testing campaign.[6] To support certification efforts, Lilium pursued concurrent validation with the U.S. Federal Aviation Administration (FAA), achieving a G-1 Certification Basis in June 2023, which aligned closely with EASA requirements and confirmed the dual-certification strategy for global market access.[6] In 2022, Lilium amended its certification timeline to accommodate refinements for the seven-seater variant, pushing the overall target to 2025 while maintaining focus on phased compliance demonstrations, including hover and transition phases informed by ongoing flight tests. Pre-insolvency milestones included the assembly of the second full-scale prototype (MSN 2) in 2024 at the Wessling facility, designated for the first piloted flights in early 2025 to gather critical certification data.[30] Lilium's production ambitions were bolstered by its 2021 public listing on Nasdaq through a SPAC merger with Qell Acquisition Corp., which raised approximately $584 million in gross proceeds upon closing to fund certification and industrialization.[31] The company outlined an aggressive ramp-up at its advanced manufacturing center in Wessling, Germany, with plans calling for initial low-rate production output of 25 units starting in late 2023, scaling to 250 aircraft in 2024 and 400 in 2025, leveraging automated processes and Tier 1 supplier partnerships to achieve high-volume eVTOL fabrication.[32] These efforts positioned Lilium to transition from prototyping to commercial-scale operations, with the Wessling site serving as the hub for fuselage assembly, propulsion integration, and final aircraft completion.[33]Insolvency and asset disposition
Despite securing approximately $1.5 billion in indicative orders from various operators and raising over $1 billion in investments since its founding, Lilium faced a severe liquidity crisis that culminated in the filing for self-administration insolvency proceedings by its German subsidiaries on October 24, 2024.[34][35] The proceedings were triggered by the German parliament's Budget Committee rejecting a loan guarantee that was a prerequisite for a planned private fundraising round, leaving the company unable to meet its financial obligations.[36] The initial self-administration process allowed Lilium to continue limited operations while seeking restructuring or buyers, but subsequent efforts faltered. In November 2024, the company initiated an M&A process to explore program continuation or asset sales, followed by a provisional agreement in December 2024 to sell its operating units to an investor consortium.[37][38] However, this rescue deal collapsed, leading to a second insolvency filing in February 2025 after the consortium failed to provide the anticipated €200 million investment, resulting in the termination of all operations and the layoff of nearly 1,000 employees by late December 2024.[39][40] By mid-2025, the insolvency proceedings had shifted to the piecemeal disposition of assets to maximize creditor recovery. In October 2025, U.S.-based eVTOL developer Archer Aviation won a competitive auction for Lilium's intellectual property portfolio, acquiring approximately 300 patents related to ducted fan technology and eVTOL systems for €18 million ($21 million), outbidding competitors including Joby Aviation.[41][42] This sale marked a significant consolidation in the advanced air mobility sector, with Archer integrating the patents to enhance its own platforms.[43] Other assets, such as prototypes and battery testing facilities, were slated for separate liquidation, though no further development of the Lilium Jet program occurred following the cessation of operations. Other assets, including prototypes and testing facilities, underwent separate liquidation in mid-2025, with no further development or revival of the Lilium Jet program as of November 2025.[44]Design
Configuration and structure
The Lilium Jet is a fixed-wing electric vertical takeoff and landing (eVTOL) aircraft featuring a canard configuration without a conventional tail, designed to accommodate six passengers and one pilot in a seven-seater layout.[45] The overall structure includes a separate forward cockpit for the pilot and a rear cabin for passengers, with luggage storage at the aft end, emphasizing a compact footprint compatible with existing helipads (D-value under 14 meters).[45] The airframe utilizes a high-performance carbon fiber composite construction to achieve a lightweight design.[46] Key dimensions of the production model include a wingspan of 13.7 m, overall length of 11 m, and height of approximately 4 m, enabling efficient regional operations while maintaining structural integrity for vertical and forward flight modes.[47] The design evolved from an initial five-seater prototype, tested in 2019, to the current seven-seater variant optimized for passenger transport, incorporating refinements for improved capacity and aerodynamics.[48] The VTOL mechanism relies on distributed electric propulsion with 30 ducted fans embedded within flaps on the main wings and forward canards, allowing thrust vectoring through flap deflection rather than rotor tilting.[49] In hover, the flaps deflect downward to direct thrust vertically, while in cruise, they align flush with the wing surfaces to minimize drag.[45] This integration eliminates the need for separate nacelles, reducing weight and aerodynamic losses.[48] Aerodynamically, the Lilium Jet employs high aspect ratio wings to enhance lift-to-drag efficiency during cruise flight, generating approximately 60% of the total lift, complemented by the canards contributing about 20% for pitch stability.[48] The ducted fan design further supports quiet operation, targeting noise levels below 60 dB(A) at 100 m during takeoff through enclosed propulsion that mitigates external noise propagation.[50] The propulsion fans are integrated directly into the flaps for control, with the canard-to-main-wing fan ratio adjusted in the production model to optimize balance and performance.[51]Propulsion and power systems
The Lilium Jet's propulsion system is based on an all-electric architecture utilizing 30 ducted electric fans distributed across the canards and main wings.[52] These fans provide vectored thrust for vertical takeoff and landing (VTOL) as well as efficient forward flight, with the design emphasizing low noise through enclosed propulsion units featuring acoustic liners.[53] Each fan is powered by a high-density electric motor developed in-house, capable of delivering over 100 kW from a unit weighing just over 4 kg, enabling peak total hover power in the range of several megawatts across the array.[54] The power system centers on a modular lithium-ion battery pack using custom silicon-anode cells produced in partnership with Customcells, configured as 10 independent packs for redundancy and safety.[55][56] These packs support high power output for VTOL operations while maintaining reserves for safe landing, with an overall capacity targeted at approximately 300 kWh and energy density exceeding 300 Wh/kg in advanced configurations.[57] Power distribution employs decentralized inverters, one per fan, to optimize efficiency and fault tolerance, incorporating regenerative energy capture during descent to extend operational margins.[29] This propulsion setup achieves total VTOL thrust sufficient to support the aircraft's maximum takeoff weight of around 3,175 kg, estimated at over 30 kN, while in cruise mode, the fixed-wing configuration leverages aerodynamic lift for energy efficiency roughly 50% superior to conventional helicopters on equivalent missions.[50] Ongoing developments focused on further enhancing battery energy density to enable a targeted range of 250 km, aligning with regional air mobility goals.[58] The intended design for the production model was not realized following the company's insolvency in 2025.[10]Avionics and flight controls
The Lilium Jet employs a fully digital fly-by-wire flight control system developed by Honeywell, which manages all moveable surfaces including the flaps on the main wings and canards, as well as thrust vectoring achieved through differential control of the 30 ducted electric fans for enhanced stability during hover and transition phases.[59][60] This system incorporates redundant actuators to ensure reliability, eliminating traditional mechanical linkages and enabling precise, automated adjustments for seamless mode transitions between vertical takeoff, hover, and forward cruise flight.[59] The avionics suite features an integrated Honeywell glass cockpit designed to minimize pilot training requirements and support single-pilot operations, including multifunction displays for navigation, communication, and surveillance.[59] Complementary Garmin standby flight instruments provide redundant display capabilities for critical parameters such as attitude, airspeed, and altitude, enhancing operational resilience.[61] The system includes software for real-time monitoring of flight modes and integration with custom-engineered Honeywell sensors to support navigation and system health assessment during all flight phases.[62][63] Safety is prioritized through a triple-redundant flight control computer architecture, which continuously cross-checks data from independent processing units to maintain control integrity even in the event of a single or dual failure.[64][24] This redundancy extends to the fly-by-wire system's integration with distributed propulsion controls, allowing automatic redistribution of thrust for stable flight and emergency procedures such as controlled descent.[65] The avionics also incorporate protocols for hover hold and safe landing sequences, leveraging sensor inputs to automate responses to anomalies while keeping the pilot in the loop for oversight.[21] The Lilium Jet is engineered for single-pilot operation, with avionics that automate routine tasks to allow the pilot to focus on monitoring and decision-making, though full autonomy remains a long-term development goal rather than a current capability.[59][66] Advanced sensor fusion, including cameras and potential integration of LIDAR and radar derived from patented technologies, supports detect-and-avoid functions to enhance situational awareness in complex airspace environments.[67]Specifications
General characteristics
The Lilium Jet was configured for one pilot and up to six passengers in a premium cabin layout, with a maximum payload capacity of 700 kg.[50] The aircraft's overall dimensions included a wingspan of 13.9 m and canard span of 6.3 m, enabling a compact footprint suitable for existing heliport infrastructure without major modifications.[50] Key weight parameters comprised an empty weight of approximately 1,524 kg and a maximum takeoff weight of 3,175 kg.[50] Propulsion was to be achieved through 30 electric ducted fans integrated into the wings and canard, eliminating traditional exposed propellers for enhanced safety and noise reduction.[53] The power system was to rely on lithium-ion batteries with a total capacity of 305 kWh, distributed across multiple packs to support redundant and safe flight profiles.[50]| Characteristic | Specification |
|---|---|
| Crew | 1 pilot |
| Passengers | 6 |
| Maximum payload | 700 kg |
| Wingspan | 13.9 m |
| Canard span | 6.3 m |
| Empty weight | ≈1,524 kg |
| Max takeoff weight | 3,175 kg |
| Electric ducted fans | 30 |
| Battery capacity | 305 kWh (lithium-ion) |
Performance metrics
The Lilium Jet was engineered for high-speed regional travel, with a targeted maximum speed of 300 km/h (186 mph) and a cruise speed of 252 km/h (157 mph) as of 2024.[50][3] The aircraft was designed to transition from hover to forward flight at speeds exceeding 100 km/h, enabling efficient progression to wing-borne cruise. On a full charge, the Lilium Jet was targeted to achieve a range of approximately 178 km (96 nm) as of 2024, supporting missions with approximately 60 minutes of cruise endurance.[3][68] Its service ceiling was to reach 3,000 m (9,800 ft), while the climb rate in hover was 500 m/min.[50] The design emphasized low noise and high efficiency, with takeoff noise below 65 dB at 100 m and specific energy consumption of approximately 200 Wh/km during cruise.[50][69] Compared to conventional helicopters, the Lilium Jet was projected to offer about 50% better fuel economy equivalent, driven by its ducted electric propulsion system.[68] These specifications represent design targets as of late 2024 for the Lilium Jet; the program was canceled in February 2025 following insolvency, without achieving full certification or production.[10]| Metric | Value | Notes/Source |
|---|---|---|
| Maximum speed | 300 km/h (186 mph) | Design target[50] |
| Cruise speed | 252 km/h (157 mph) | Targeted as of 2024 at 3,000 m altitude[3] |
| Hover transition speed | >100 km/h | Demonstrated in testing |
| Range | ≈178 km (96 nm) | Targeted full charge, 7-seater configuration as of 2024[3] |
| Cruise endurance | 60 minutes | Typical mission profile[68] |
| Service ceiling | 3,000 m (9,800 ft) | Operational envelope[50] |
| Climb rate (hover) | 500 m/min | Vertical ascent capability[50] |
| Takeoff noise | <65 dB at 100 m | At hover/transition[50] |
| Specific energy consumption (cruise) | ~200 Wh/km | Electric efficiency metric[69] |
| Fuel economy equivalent | 50% better than helicopters | Relative to rotorcraft baselines[68] |