Lilium Cuts Jet Engines to 30 in Design Freeze for EASA Approval

Aircraft Development Update — Lilium

Lilium

Enlarging ducted fan diameters allows Lilium to trim engine and battery counts without sacrificing thrust, preserving the power density required to hit its 175-kilometer commercial range target.

AI-assisted summary of Aircraft Development Update — original source. Check the original for full context.

Source published:

Key ideas

  • Lilium has converged its production aircraft design post-PDR, enlarging ducted fan diameter slightly to reduce engine count from 36 to 30 and battery packs from 12 to 10 while maintaining total thrust and a 2,500 W/kg hover power density. (3:17)
  • The company submitted its complete certification Means of Compliance proposals to EASA in April 2022 and has finished two of four scheduled Design Organization Approval audits. (1:20)
  • Independent testing by Energy Assurance confirmed Lilium's exclusive Zenlabs/Customcells silicon-anode battery delivers 2,500 W/kg specific power even at a 20% state of charge. (5:54)
  • Commercial mission projections target a 175 km operational range at maximum takeoff weight with a 45-second vertical hover and landing, supported by new running landing capability for diversion reserves. (5:54)

Detailed notes

## Background Published on YouTube by Lilium on June 9, 2022, this update features Lilium's Chief Technology Officer, Alastair McIntosh, sharing progress on the company's aircraft development program. According to the description, the video covers major updates regarding the program status, aircraft design refinements, and regulatory certification.

## TL;DR Lilium CTO Alastair McIntosh outlines the maturation of the Lilium Jet following its Preliminary Design Review (PDR) and successful wing transition flight tests with the subscale demonstrator Phoenix. The update details the company's dual-track certification strategy with EASA and the FAA, supported by submitted Means of Compliance and ongoing Design Organization Approval audits. McIntosh also explains key airframe and propulsion optimizations, notably increasing ducted fan diameter to reduce engine count from 36 to 30 while adding running landing capability. Finally, performance data from Zenlabs silicon-anode cells confirms a sustained hover power density of 2,500 W/kg at 20% state of charge, underpinning a projected 175-kilometer operational mission range at maximum takeoff weight.

## Atmosphere & style The presentation carries a composed, engineering-driven atmosphere characterized by technical precision and industrial pragmatism. McIntosh speaks with the steady, measured cadence of a seasoned aerospace executive, grounding theoretical capabilities in empirical flight data and stringent regulatory milestones. Rather than relying on futuristic hype, the video delivers a methodical and reassuring account of technical convergence, conveying quiet confidence in the aircraft's transition from experimental prototype to certifiable commercial product.

## Bulletin - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) Lilium has converged its production aircraft design post-PDR, enlarging ducted fan diameter slightly to reduce engine count from 36 to 30 and battery packs from 12 to 10 while maintaining total thrust and a 2,500 W/kg hover power density. - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) The company submitted its complete certification Means of Compliance proposals to EASA in April 2022 and has finished two of four scheduled Design Organization Approval audits. - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) Independent testing by Energy Assurance confirmed Lilium's exclusive Zenlabs/Customcells silicon-anode battery delivers 2,500 W/kg specific power even at a 20% state of charge. - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) Commercial mission projections target a 175 km operational range at maximum takeoff weight with a 45-second vertical hover and landing, supported by new running landing capability for diversion reserves.

## Key takeaways - [00:05](https://www.youtube.com/watch?v=qZ73PftBfFg&t=5s) Proprietary computational toolsets augment standard aerospace software to model aerodynamics, flight control laws, acoustic profiles, and structural loads. - [00:05](https://www.youtube.com/watch?v=qZ73PftBfFg&t=5s) The subscale demonstrator Phoenix successfully achieved full wing transition and flow attachment, validating aerodynamic handover from engine thrust to fixed wings. - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) Lilium pursues EASA as its primary certification authority alongside concurrent bilateral cross-validation with the US FAA. - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) Regulatory groundwork advanced through contribution to the 2019 SC-VTOL framework, obtaining CRI-A01 in 2020, and completing two of four Design Organization Approval audits. - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) Complete certification Means of Compliance proposals were officially submitted to EASA in April 2022. - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) Following Preliminary Design Review (PDR), Lilium locked in its production design configuration with updated ducted fan dimensions. - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) Reducing total engines from 36 to 30 lowers production and maintenance costs while improving aerodynamic balance and acoustic duct damping. - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) Airframe refinements include moving the main wing higher and further aft on the fuselage, as well as adding winglets to the front canard. - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) Cruise power consumption operates at roughly one-tenth of hover power density, preserving battery capacity for regional transit. - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) Introduction of running landing capability allows short rolling landings on conventional runways, unlocking reserve battery energy during diversions. - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) Extensive architectural redundancy across 30 engines, distributed flaps, and 10 isolated battery packs is engineered to satisfy EASA's strict 10⁻⁹ catastrophic failure rate threshold. - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) Lilium secured an exclusive market agreement for Zenlabs-designed, Customcells-manufactured high-power cells validated by Energy Assurance. - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) The proprietary cell chemistry maintains a hover specific power density of 2,500 W/kg even at a depleted 20% state of charge. - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) At operational empty weight, the Lilium Jet has a projected physical range of approximately 250 kilometers (155 miles). - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) Projected operational mission range stands at ~175 km at maximum takeoff weight, including a 45-second vertical hover landing and a 20% reserve margin.

## Detailed walkthrough ### [00:05](https://www.youtube.com/watch?v=qZ73PftBfFg&t=5s) Aerodynamic Modeling and the Transition Milestone

Lilium’s aircraft architecture—centered on main wings, a front canard, and distributed electric propulsion—has remained fundamental to the company’s vision from its inception. As the technical design has matured, Lilium has supplemented standard commercial aerospace software with proprietary computational tools. These internal toolsets allow engineering teams to model aircraft and engine aerodynamics, complex flight control laws, acoustic signatures, and structural loads, providing the rapid iteration capability necessary to refine the aircraft's architecture.

Computational simulations are systematically validated against empirical physical data. Beyond controlled closed-environment wind tunnel experiments, the company relies heavily on its real-world flight test campaign. The subscale technology demonstrator, named Phoenix, has been conducting test flights since 2019 to validate the aircraft architecture in open atmospheric conditions. The program achieved a key flight-test milestone by completing wing transition and achieving flow attachment on the main wing, where aerodynamic lift is handed over from the thrust of the engines directly to the fixed wings. Alastair McIntosh highlights the significance of this phase: “This is a significant step forward. It's the most difficult maneuver that a VTOL aircraft can undertake.”

- Proprietary simulation platforms model aerodynamics, flight control laws, environmental acoustics, and structural loading. - Subscale demonstrator Phoenix has served as the real-world flight testbed since 2019. - Transition milestone proved aerodynamic flow attachment on the main wing, shifting lift generation from pure engine thrust to the wing surface.

[01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) The Certification Roadmap and Regulatory Approvals

Developing an electric vertical takeoff and landing (eVTOL) vehicle for regional air mobility requires navigating industrial and regulatory realities alongside aerodynamic engineering. McIntosh stresses that commercial viability demands a pragmatic understanding of certification from day one: “You can build something new that flies, but can't be certified. You can build something that can be certified, but can't be built at scale. You can build something at scale, but can't be sold profitably to a real market.” To anchor this effort, Lilium recruited veteran aerospace engineering leaders with proven track records of guiding complex aircraft through full regulatory approvals.

Lilium treats the European Union Aviation Safety Agency (EASA) as its primary certification authority while concurrently pursuing bilateral cross-validation with the US Federal Aviation Administration (FAA). Lilium contributed directly to EASA and EUROCAE working groups, aiding the establishment of the Special Condition for VTOL (SC-VTOL) regulatory framework published in 2019. In 2020, EASA granted Lilium its CRI-A01 certification basis, establishing the explicit technical requirements the jet must satisfy. By April 2022, Lilium submitted its complete set of certification Means of Compliance (MoC) proposals, detailing how each safety mandate will be proven. In parallel, the company completed the second of four scheduled Design Organization Approval (DOA) audits required for EASA to formally authorize Lilium to design and certify commercial aircraft. McIntosh underscores the necessity of this regulatory discipline: “An aircraft cannot be certified and launched without strict adherence to this process from the beginning. Otherwise, you only have a prototype.”

```mermaid flowchart TD accTitle: Lilium Certification Pathway accDescr: Progression of regulatory milestones from initial framework development to design organization approval audits. subgraph Regulatory_Basis["Regulatory Basis"] A["SC-VTOL Framework (2019)<br/>Co-developed with EASA & EUROCAE"] --> B["CRI-A01 Certification Basis (2020)<br/>Formal requirements set by EASA"] end subgraph Compliance_Audits["Compliance & Approvals"] B --> C["Means of Compliance Proposals (April 2022)<br/>Methods to demonstrate safety"] C --> D["Design Organization Approval (DOA)<br/>2 of 4 audits completed"] D --> E["Concurrent FAA Cross-Validation<br/>Dual-market commercial pathway"] end ```

- Primary authority: EASA; secondary concurrent validator: FAA. - SC-VTOL regulatory foundation published in 2019 with Lilium's working-group participation. - CRI-A01 certification basis received from EASA in 2020. - Complete Means of Compliance (MoC) proposals submitted to EASA in April 2022. - Two of four planned EASA DOA audits successfully completed.

[03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) PDR Convergence and Airframe Optimization

Following the completion of its preliminary design review (PDR), Lilium locked in its production aircraft design configuration. McIntosh expresses strong conviction in this frozen configuration: “We've converged on a final design, which we have every confidence safely achieves the performance our launch customers require.” Central to this update is the optimization of the electric ducted fan architecture. By increasing the diameter of the ducted fans by a few percent, engineers were able to trim the engine count down from 36 to 30 while delivering identical total thrust and system efficiency. This change enhances the aerodynamic balance between the main wing and canard, decreases manufacturing and maintenance costs, and allows for superior acoustic damping liners inside the ducts to suppress community noise.

Airframe adjustments accompany the propulsion refinement: the main wing has been moved slightly aft and higher on the fuselage, and winglets were added to the canard to clean up airflow and boost aerodynamic efficiency. Cruise power density is reduced to one-tenth of hover power density, preserving battery capacity for extended range. The revised propulsion architecture preserves a 3:1 engine-to-battery ratio, meaning the total battery pack count scales down from 12 to 10 units while maintaining an overall hover power density of roughly 2,500 W/kg in a lighter package.

Lilium also incorporated running landing capability to enhance operational flexibility and satisfy certification reserve mandates. This landing mode allows the aircraft to divert to conventional runway alternatives and execute a short rolling touchdown, tapping into battery energy reserves that cannot be safely depleted during a pure vertical landing. To achieve commercial air transport certification, the architecture uses extensive redundancy—spanning 30 independent engines, distributed control flaps, 10 separated battery packs, and multiple flight control computers—to satisfy EASA's strict failure probability threshold of $10^{-9}$, or less than one catastrophic failure per one billion flight hours.

- Ducted fan diameter increased by a few percent, reducing the total engine count to 30. - Battery pack count reduced from 12 to 10, maintaining a 3:1 engine-to-pack ratio. - Hover power density preserved at ~2,500 W/kg; cruise power density sits at 1/10th of hover power. - Geometric changes: main wings shifted upward and rearward; canard equipped with winglets. - Running landing capability added to unlock reserve energy margins and facilitate airport diversions. - Redundant architecture engineered to satisfy the commercial $10^{-9}$ safety standard ($\le 1$ catastrophic failure per $10^9$ flight hours).

[05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) High-Power Cell Architecture and Mission Range Targets

The energy storage system powering the Lilium Jet is the result of years of screening dozens of cell formats. Lilium selected a proprietary cell designed by Zenlabs and manufactured by Customcells, secured under an exclusive supply agreement for Lilium's market segment. McIntosh emphasizes the significance of this selection: “The battery is exclusive to Lilium within our target market and we believe it could be one of the highest performance cells that is practical for eVTOL in existence today.” Unlike standard market cells that specialize either in high specific energy or high specific power, independent test data from Energy Assurance demonstrates that the Zenlabs silicon-anode cell delivers both simultaneously. Crucially, the cell sustains its required hover specific power output of 2,500 W/kg down to a 20% state of charge (SoC).

These engineering parameters substantiate the program's commercial mission specifications. At operational empty weight (OEW), the jet maintains a projected physical range of approximately 250 kilometers (155 miles) when executing a short vertical takeoff and landing. Under real-world commercial operations at maximum takeoff weight (MTOW), the jet delivers a projected operational mission radius of roughly 175 kilometers. This operational profile incorporates a vertical takeoff, cruise, and a conservative 45-second vertical hover and landing sequence, terminating with 20% battery state of charge remaining. McIntosh notes that these operational calculations deliberately omit the supplemental reserve margins made accessible by the new running landing capability. As energy storage technology advances, Lilium plans to integrate upgraded battery chemistries into the airframe to expand passenger stage lengths over time.

- Cell partner: Zenlabs (design) and Customcells (manufacturing), exclusive to Lilium in its segment. - Performance validated by independent testing firm Energy Assurance. - Sustained power output: 2,500 W/kg at 20% state of charge. - Physical range: ~250 km (155 miles) at operational empty weight with short VTOL. - Projected operational range: ~175 km at maximum takeoff weight, factoring in a 45-second vertical hover landing and a 20% reserve SoC. - Rolling landing capability provides additional reserve margins beyond base operational range figures.

## Notable quotes > [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) You can build something new that flies, but can't be certified. You can build something that can be certified, but can't be built at scale. You can build something at scale, but can't be sold profitably to a real market. — Alastair McIntosh

## Mentioned Alastair McIntosh, Lilium, Phoenix, European Union Aviation Safety Agency, Federal Aviation Administration, EUROCAE, Zenlabs, Customcells, Energy Assurance, Lilium Jet

## Video description Lilium's Chief Technology Officer, Alastair McIntosh, provides an update on the program, aircraft design, and certification.

[Source](https://www.youtube.com/watch?v=qZ73PftBfFg)

中文简报

Lilium定型设计削减发动机至30台以争取EASA认证 通过增大涵道风扇直径，Lilium在不牺牲推力的情况下减少了发动机和电池数量，保持了实现175公里商业航程目标所需的功率密度。 Lilium首席技术官Alastair McIntosh概述了Lilium Jet在完成初步设计审查（PDR）以及缩比验证机Phoenix成功完成机翼过渡飞行测试后的成熟进展。该更新详细说明了公司面向EASA和FAA的双轨认证战略，并以已提交的符合性验证方法以及正在进行的设计机构批准审核为支撑。McIntosh还解释了关键的机体和推进系统优化，特别是通过增大涵道风扇直径将发动机数量从36台削减至30台，同时增加了滑跑着陆能力。最后，Zenlabs硅阳极电池的性能数据证实，在20%荷电状态下仍能维持2,500瓦/千克的悬停功率密度，为最大起飞重量下预计175公里的运营任务航程提供了支撑。 Lilium在PDR后收敛了其量产机型设计，通过略微增大涵道风扇直径，将发动机数量从36台减少至30台，电池包从12个减少至10个，同时保持了总推力以及2,500瓦/千克的悬停功率密度。 (3:17) 该公司于2022年4月向EASA提交了完整的认证符合性验证方法提案，并已完成了四次计划中的设计机构批准审核中的两次。 (1:20) Energy Assurance的独立测试证实，Lilium专有的Zenlabs/Customcells硅阳极电池即使在20%荷电状态下也能提供2,500瓦/千克的比功率。 (5:54) 商业任务预测目标是在最大起飞重量下实现175公里的运营航程，并包括45秒的垂直悬停与着陆，同时具备用于备降储备的新滑跑着陆能力支持。 (5:54)

Reading summary

Lilium has frozen its production aircraft design and advanced its regulatory framework, combining subscale flight testing, airframe and propulsion optimizations, and high-power battery cells to target regional air mobility. Aerodynamic Validation and Wing Transition (0:05) Lilium validates its canard, main wing, and distributed electric propulsion configuration using proprietary computational tools alongside physical flight testing. Its subscale demonstrator, Phoenix, which has conducted flight tests since 2019, validated the aircraft architecture in atmospheric conditions by completing wing transition and achieving flow attachment on the main wing. This handover transfers lift generation from pure engine thrust directly to the fixed wing surface, which Chief Technology Officer Alastair McIntosh describes as the most difficult maneuver for a vertical takeoff and landing aircraft. Dual-Track Certification and Redundancy Architecture (1:20) Lilium treats the European Union Aviation Safety Agency (EASA) as its primary authority while concurrently pursuing cross-validation with the US Federal Aviation Administration. Following its involvement in drafting EASA's 2019 SC-VTOL framework, the company obtained its CRI-A01 certification basis in 2020, submitted its complete Means of Compliance proposals in April 2022, and completed two of four scheduled Design Organization Approval audits. PDR Convergence and Airframe Optimization (3:17) Following preliminary design review convergence, Lilium locked in its production design by increasing ducted fan diameters by a few percent, allowing engineers to reduce engine count from 36 to 30 while maintaining identical total thrust, system efficiency, and acoustic damping. The battery count was reduced from 12 to 10 packs, preserving a 3:1 engine-to-pack ratio and a hover power density of roughly 2,500 W/kg, while cruise power density drops to one-tenth of hover requirements. Airframe adjustments include shifting the main wing aft and higher on the fuselage, adding canard winglets to improve airflow, and incorporating running landing capability. This conventional landing mode permits short rolling touchdowns on runways, allowing the aircraft to access reserve margins during diversions without relying on a pure vertical descent. Redundant architecture—spanning 30 engines, distributed flaps, 10 packs, and multiple computers—is engineered to meet EASA's commercial safety threshold of no more than one catastrophic failure per one billion flight hours. Cell Performance and Operational Mission Targets (5:54) The aircraft uses proprietary silicon-anode cells designed by Zenlabs and manufactured by Customcells under an exclusive agreement for Lilium's market segment. Independent testing by Energy Assurance confirmed that the cell sustains a hover specific power output of 2,500 W/kg down to a 20% state of charge, delivering high specific energy and high specific power concurrently. At operational empty weight with a short vertical takeoff and landing, the jet has a projected physical range of approximately 250 kilometers (155 miles). Under commercial operations at maximum takeoff weight, the projected operational radius is roughly 175 kilometers, assuming a 45-second vertical hover landing and a 20% reserve state of charge, excluding supplemental margins provided by running landings. Lilium plans to expand stage lengths by integrating upgraded battery chemistries over time, though commercial success remains dependent on completing the remaining Design Organization Approval audits, securing bilateral EASA and FAA airworthiness approvals, and proving production aircraft meet projected operational ranges.

精炼阅读摘要

Lilium在其机型研发更新中阐述了其全电垂直起降（eVTOL）飞机的技术收敛、适航审定路径与电池推进系统，首席技术官Alastair McIntosh强调公司正从原型阶段向符合商业运营与适航监管标准的量产构型过渡。 气动验证与机翼过渡飞行里程碑 (0:05) Lilium的机体架构基于主翼、前置鸭翼以及分布式电力推进系统。为了对该架构进行工程迭代，公司在商业航天软件基础上开发了专有计算工具，用于模拟空气动力学、复杂飞行控制律、声学特征以及结构载荷。这些数值模拟依赖风洞实验与实际飞行测试进行双重验证。 自2019年起，缩比技术验证机Phoenix在开放大气环境下开展飞行测试。测试期间，该机完成了主翼过渡并实现主翼气流附着，成功将升力产生机制由纯发动机推力交接给固定机翼表面。McIntosh将这一过渡阶段定性为垂直起降航空器难度最高的核心机动动作。 双边适航审定框架与合规推进 (1:20) Lilium将欧洲航空安全局（EASA）作为主要适航审查机构，并同步寻求美国联邦航空管理局（FAA）的双边交叉验证。针对商用适航法规，Lilium参与了EASA与EUROCAE工作组，推动了2019年发布的SC-VTOL法规框架的制定，并于2020年获得EASA签发的CRI-A01审定基础。 在审定执行层面，Lilium于2022年4月向EASA提交了完整的符合性方法（MoC）提案，明确证明各项安全指标的技术路径。同时，公司已完成正式获得商业航空器设计与审定授权所需的四次设计组织批准（DOA）审计中的前两次。McIntosh指出，缺乏全流程合规自律的项目最终只能停留在原型阶段，无法进入规模化与商业盈利环节。 初步设计评审后的机身与涵道优化 (3:17) 通过初步设计评审（PDR）后，Lilium冻结了量产飞机的设计配置。工程团队将电动涵道风扇直径微增数个百分点，在维持总推力与系统效率不变的前提下，将发动机总数从36台削减至30台。该改动改善了主翼与鸭翼的气动平衡，降低了制造与维护成本，并在涵道内为降噪衬层留出空间。 伴随推进系统调整，机体布局将主翼位置适度向后、向上调整，并在鸭翼上加装翼梢小翼以提升气动效率。动力系统保持3:1的发动机与电池配比，电池包数量由12组减少到10组，悬停功率密度维持在约2,500 W/kg，而巡航功率密度则降至悬停阶段的十分之一。此外，飞机新增滑行着陆能力，使机组在备降跑道时无需消耗纯垂直降落所需的严苛电量储备；机体通过30台独立发动机、多套飞控计算机及分布式控制翼面等冗余设计，满足EASA要求的 catastrophic 故障率低于十亿分之一飞行小时（10⁻⁹）的标准。 电池单体技术与实际航程指标 (5:54) Lilium Jet采用由Zenlabs设计、Customcells制造的硅负极专有电芯，并在其目标细分市场享有排他性供应协议。第三方检测机构Energy Assurance的独立测试数据表明，该电芯兼具高比能量与高比功率，且在电池荷电状态（SoC）下降至20%的工况下，仍能维持悬停所需的2,500 W/kg输出功率。 基于该电池性能与气动构型，在执行短距垂直起降模式下，飞机在使用空重（OEW）时的物理航程预计约为250公里（155英里）。在最大起飞重量（MTOW）的实际商业运营场景下，包含垂直起飞、巡航以及预留45秒悬停着陆和20%剩余电量时，预计运营航程约为175公里。该测算尚未将滑行着陆释放出的额外储备电量计入基础航程；公司计划随着未来电池能量密度提升，进一步延长机型的航段距离。 Lilium通过固化30发构型与提交符合性方法提案推进商用进程，但其设定的175公里运营航程与10⁻⁹安全裕度，仍有待全尺寸机型的全面试飞、剩余两阶段DOA审计以及EASA与FAA双边适航审批的最终验证。

Detailed notes — zh

## Background 该视频由电动垂直起降飞行器研发企业 Lilium 于 2022 年 6 月 9 日发布在 YouTube 官方频道。视频简介指出，Lilium 首席技术官 Alastair McIntosh 在本期内容中系统介绍了研发项目进展、飞行器设计演进以及适航审定等关键维度的最新动态。 ## TL;DR 视频系统盘点了 Lilium 飞行器在技术研发、工程优化与适航合规方面的关键里程碑。Phoenix 验证机成功实现了主翼平飞转换与气流附着，有效验证了计算仿真体系与分布式推进架构的可靠性。在适航审定方面，公司以 EASA 的 SC-VTOL 规章为基准并配合 FAA 交叉验证，已提交全套符合性验证方法（MoC）方案并完成两轮 DOA 审计。此外，经过初步设计评审（PDR），团队优化了涵道风扇直径、将发动机缩减至 30 台并引入短距滑跑着陆能力，同时第三方测试也证实了其定制电芯在 20% 低电量下仍能输出充沛功率，确保在兼顾 10⁻⁹ 安全冗余的同时稳步迈向商业化航程目标。 ## Atmosphere & style 整段汇报散发着严谨务实、理性克制的专业工程质感。McIntosh 的叙述清晰冷静，毫无夸张浮躁的商业宣发色彩，而是以一名资深航空航天专家的视角，坦诚剖析了从“造出一架能飞的原型机”到“完成适航审定并实现规模化盈利”之间的现实鸿沟。技术数据的逐一展示与试飞突破相呼应，既传递出团队攻克严苛工程挑战后的从容自信，也营造出一种稳扎稳打、敬畏航空安全法规的笃定氛围。 ## Bulletin - [00:05](https://www.youtube.com/watch?v=qZ73PftBfFg&t=5s) Phoenix 验证机已成功实现主翼平飞转换与气流附着，升力主要转向由机翼产生，攻克了垂直起降飞行器中最具挑战性的关键飞行动作。 - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) 适航审定稳步推进，Lilium 已于 2022 年 4 月提交全套符合性验证方法（MoC）提案，并已完成 EASA 设计组织批准（DOA）四轮审计中的前两轮。 - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 初步设计评审（PDR）收敛后全机锁定为 30 台电动涵道发动机配 10 个电池包，微调扩大涵道直径以优化气动平衡与声学降噪，并引入短距滑跑着陆能力拓宽备降储备。 - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) 独家合作的 Zenlabs/Custom Cells 电芯经第三方独立机构实测，在放电至 20% SoC 时仍能稳定输出 2,500 W/kg 高比功率，支持整机在标准运营工况下实现约 175 公里的实际航程。 ## Key takeaways - [00:05](https://www.youtube.com/watch?v=qZ73PftBfFg&t=5s) Lilium 坚持主翼加前鸭翼与分布式电推进的基础架构，结合商业软件与自研计算工具构建涵盖气动、飞控律与载荷的多学科仿真迭代体系。 - [00:05](https://www.youtube.com/watch?v=qZ73PftBfFg&t=5s) Phoenix 验证机在实机试飞中实现主翼平飞转换与气流附着，证明该气动架构能够顺利从动力推力升力过渡至高效的机翼气动升力。 - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) 从项目早期即严格遵循适航审定标准至关重要，缺乏适航合规路径与量产可行性的飞行器充其量只是无法投入商业运营的原型机。 - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) Lilium 以 EASA 为主审机构并同步推进 FAA 交叉验证，继 2019 年 SC-VTOL 规章和 2020 年 CRI A01 文件后，于 2022 年 4 月正式提交全套符合性验证方法（MoC）。 - [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) 在取得设计组织批准（DOA）的关键流程中，Lilium 顺利通过了 EASA 规划的四轮审核中的前两轮。 - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 初步设计评审后微调放大了涵道风扇直径，在维持总推力与效率的前提下将发动机数量精简至 30 台，降低了单机制造与全生命周期维护成本。 - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 涵道直径的微调改善了主翼与前鸭翼之间的气动力平衡，同时更大的空间允许机体布置更完善的吸音衬垫以抑制运行噪音。 - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 动力拓扑精简为 10 个电池包驱动 30 台发动机（保持 3:1 匹配），在维持约 2,500 W/kg 悬停功率密度的同时降低了结构死重与系统复杂度。 - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 机体气动外形经优化后，巡航状态下的功率密度仅为悬停状态的十分之一，大幅提升了飞行巡航阶段的能量利用效率。 - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 方案正式引入短距滑跑着陆（running landing）能力，使飞行器在应对备降工况时能比纯垂直降落释放出更多电池储备能量。 - [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 依托 30 台独立发动机、多重舵面、分布式电池包和多余度飞控计算机，飞行器设计满足每飞行小时灾难性故障率低于十亿分之一（10^-9）的航空安全标准。 - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) 动力电池选定由 Zenlabs 设计并由 Custom Cells 制造的专用电芯，同时兼顾了高比能量与高比功率，打破了行业常规的性能权衡限制。 - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) 第三方机构 Energy Assurance 测试表明，该电芯在电量降至 20% SoC 时仍能稳定输出 2,500 W/kg 功率，确保在低电量状态下具备充足的垂直着陆动力。 - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) 飞行器运行空重下的物理极限航程达 250 公里，在最大起飞重量、含 45 秒悬停及保留 20% SoC 的严苛工况下实际运营航程约为 175 公里。 - [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) 当前航程测算基于保守的垂直悬停能耗模型，尚未计入滑跑着陆模式额外释放的 20% 电量储备，未来随电芯演进还可实现电池无缝升级。 ## Detailed walkthrough ### [00:05](https://www.youtube.com/watch?v=qZ73PftBfFg&t=5s) 架构演进、计算仿真与 Phoenix 验证机飞行测试 Lilium 首席技术官 Alastair McIntosh 指出，采用主翼与鸭翼布局搭配分布式电推进（distributed propulsion）的基础飞行器架构，自公司创立初期便始终未变。随着设计细节的持续演进，研发团队的工具链也随之迭代。除了利用市售的商业软件，Lilium 还自主开发了多项内部计算工具，用于针对飞行器与发动机空气动力学、飞控律（flight control laws）、环境噪音以及结构载荷等多个维度进行建模与深度分析。这套分析体系使团队能够快速迭代并细化架构中的细微工程细节。 计算分析在经过实体测试的校准与验证后能够发挥更大的效能。McIntosh 提到，这包括在密闭环境下以真实飞行工况对标模拟的真实风洞试验，以及至关重要的实机飞行测试。自 2019 年以来持续进行试飞的“Phoenix”技术验证机，其核心任务正是检验该架构在实际飞行条件下的表现。 近期，Phoenix 验证机成功实现了主翼上的平飞转换（transition）与气流附着（flow attachment）。在这一阶段，飞行器的升力主要由机翼产生，而非依赖发动机推力。McIntosh 强调这是项目取得的重大突破：“This is a significant step forward. It's the most difficult maneuver that a VTOL aircraft can undertake.”（这是向前迈出的重要一步，也是垂直起降飞行器所能执行的最困难的机动动作。） ```mermaid flowchart LR accTitle: Lilium 飞行器设计与验证闭环 accDescr: 展示从计算工具建模到风洞与实机测试验证闭环的流程 subgraph Computation["计算与仿真"] A["商业软件 + 自研计算工具"] --> B["多学科建模<br>(气动/飞控律/载荷/噪音)"] end subgraph Validation["试验与实证"] B --> C["风洞试验校准"] C --> D["Phoenix 验证机试飞"] D --> E["突破性进展：<br>主翼转换与气流附着"] end E -.->|"数据回传迭代"| A ``` ### [01:20](https://www.youtube.com/watch?v=qZ73PftBfFg&t=80s) 适航审定路径与关键里程碑（EASA、FAA、DOA） 推动区域空中交通（Regional Air Mobility）的变革绝不仅仅依赖创新技术。McIntosh 剖析了现实维度的严峻挑战：“You can build something new that flies, but can't be certified. You can build something that can be certified, but can't be built at scale. You can build something at scale, but can't be sold profitably to a real market. So, this requires a very sober understanding of the certification process.”（你可以造出一架能飞的新型飞行器，但它可能无法通过适航审定；你可以造出一架能通过审定的飞行器，但它可能无法实现规模化量产；你可以规模化量产，但在真实市场上它可能无法盈利。因此，这需要对适航审定流程有极其清醒的认识。）这也正是 Lilium 引入大批具备实际适航审定交付经验的航空航天资深技术领军人物的原因。 欧洲联盟航空安全局（EASA）是 Lilium 的主要适航审定主管机构，与此同时，团队正与美国联邦航空管理局（FAA）开展并行的交叉验证（concurrent cross-validation）。通过深度参与 EASA 和 EUROCAE 的多个工作组，Lilium 推动并见证了 2019 年 SC-VTOL 适航审定规章的发布，以此为基准正式展开飞行器设计。随后在 2020 年，Lilium 获得了 EASA 颁发的审定基础文件（CRI A01），明确了飞机必须满足的特定技术与安全指标。 在合规推进方面，Lilium 于同年 4 月正式提交了整套符合性验证方法（Means of Compliance, MoC）提案，确立了满足安全标准的具体路径。而在设计组织批准（DOA）方面，Lilium 规划的四轮审核中已经顺利完成第二轮审核，标志着工程团队在获得 EASA 完全资质认可的道路上稳步前行。McIntosh 总结道：“An aircraft cannot be certified and launched without strict adherence to this process from the beginning. Otherwise, you only have a prototype.”（如果从一开始就不严格遵循这一流程，飞行器就无法通过审定并投入商用；否则，你手里拥有的只是一架原型机而已。） - **主要审定机构**：EASA（主审机构），同时与 FAA 进行交叉认可。 - **2019 年**：参与制定并促成 SC-VTOL 规章发布。 - **2020 年**：获得 EASA CRI A01 审定基础。 - **2022 年 4 月**：提交全套符合性验证方法（MoC）方案。 - **DOA 进展**：完成 4 轮 EASA 审计中的前 2 轮。 ### [03:17](https://www.youtube.com/watch?v=qZ73PftBfFg&t=197s) 初步设计评审（PDR）与飞机架构关键细节优化 在完成严格的初步设计评审（PDR）后，Lilium 锁定了最终构型。这套方案在兼顾首发客户性能需求的同时，确保具备适航可行性并支持规模化盈利生产。设计收敛过程中最具标志性的变化发生在其电动涵道风扇发动机（electric ducted fan engines）上：工程团队将涵道风扇直径微调放大了数个百分点。这一改动使得在保持总推力与效率不变的前提下，成功减少了发动机的总数量，并实现了主翼与前鸭翼之间更出色的气动力平衡。此举不仅降低了单机制造与后期维护成本，更大的涵道直径也让机体能够布置更佳的吸音衬垫，大幅抑制运行噪音。 在动力系统与整机气动气动布局上，发动机总数调整为 30 台，系统继续保持 3 台发动机对应 1 个电池包的动力拓扑。因此，全机电池包总数由 12 个缩减至 10 个，在减轻结构重量、简化系统集成的同时，依然维持了约 2,500 W/kg 的整机悬停功率密度。机体设计细节也有所精进：主翼位置略微向后、向上移动；鸭翼末端增加了小翼（winglets），改善了整机的气动品质与飞行效率。这些气动优化使得巡航状态下的功率密度仅为悬停状态的十分之一（1/10），显著提升了航程表现。 此外，设计方案正式引入了滑跑着陆能力（running landing capability）。这项特性对适航审定至关重要，它赋予飞行器在现实复杂工况下备降至备降场并进行短距滑跑着陆的能力，从而释放出比标准垂直着陆更充裕的电池备用能量，显著拓宽了储备航程。在系统安全性层面，全机搭载的 30 台发动机、多重舵面襟翼、独立的电池单元以及多余度飞控计算机构建了坚固的冗余保护，确保达到商用客机与 eVTOL 极其严苛的 $10^{-9}$ 安全标准，即发生灾难性故障的概率小于或等于每飞行小时十亿分之一。 | 优化系统 / 部件 | 调整前 / 初始设想 | 优化后最终设计 | 带来的工程效益 | |:--- |:--- |:--- |:--- | | **涵道风扇发动机** | 较小直径，更多引擎数量 | 涵道直径增加数个百分点，发动机减至 30 台 | 维持推力与效率；改善鸭翼与主翼气动平衡；降低单机制造与维护成本；便于声学降噪 | | **电池组架构** | 12 个电池包（3:1 架构） | 10 个电池包（维持 3:1 匹配） | 包装更轻巧简化，维持约 2,500 W/kg 悬停功率密度 | | **气动气动外形** | 原始主翼与鸭翼设计 | 主翼向后、向上微调；前鸭翼加装小翼 | 优化整机飞行操稳与气动效率；巡航功率密度降至悬停的 1/10 | | **着陆安全模式** | 单一垂直着陆依赖 | 增加短距滑跑着陆（running landing）能力 | 增强应对突发工况的备降能力；释放更多电池能量储备用于应急航程 | ### [05:54](https://www.youtube.com/watch?v=qZ73PftBfFg&t=354s) 电池技术选型、独立测试验证与实际航程测算 在过去数年中，电池团队对数十种候选电芯进行了严格筛选，最终敲定由 Zenlabs 设计、Custom Cells 制造的专用电芯。该电芯在 Lilium 的目标市场中享有独占使用权，被视为目前 eVTOL 领域极具实用价值的高性能电芯之一。McIntosh 指出，Zenlabs 电芯的独特优势在于同时兼备了卓越的比能量（specific energy）和比功率（specific power）。不同于市面上常见的“高功率但低能量”或“高能量但低功率”商业电芯，Zenlabs 电芯全面超越了这两类方案。由第三方独立机构 Energy Assurance 实施的测试结果证实，该电芯即使在放电至 20% 荷电状态（State of Charge, SoC）时，依然能稳定输出 2,500 W/kg 的高比功率，确保垂直降落阶段的充沛动力。 结合整机各项气动与动力参数，Lilium 确认其性能依然处于达成既定目标的轨道上：在运行空重状态、采用简短垂直起降工况下，物理极限航程约为 250 公里（155 英里）。而在最大起飞重量（MTOW）下，包含标准垂直起飞、着陆阶段持续 45 秒悬停，并确保着陆后仍保留 20% SoC 的前提下，预计实际运行航程约为 175 公里。 针对外界对这些测算的常见误读，McIntosh 专门澄清：该航程模型在垂直悬停阶段采用了非常保守的功率消耗假设，并且上述航程数据尚未计入滑跑着陆模式额外释放出的 20% 储备电量。最终的商业运营航程将充分纳入这些法定储备及适航要求，并在投入商业运营（EIS）之前完成最终确定。McIntosh 展望道，在投产初始阶段实现的约 250 公里物理航程足以完全覆盖 Lilium 的预设首发航线；随着未来电芯技术与性能的持续演进，飞机将能够无缝升级搭载新一代电池，为客户提供更为长远的航程体验。 - **电芯供应商**：Zenlabs 设计，Custom Cells 制造（在目标市场对 Lilium 独家供应）。 - **功率性能实证**：第三方机构 Energy Assurance 验证，在 20% SoC 状态下仍能提供 2,500 W/kg 比功率。 - **物理极限航程**：运行空重工况下约 250 公里（155 英里）。 - **标准运营航程**：最大起飞重量（MTOW）+ 45 秒垂直着陆悬停 + 落地剩余 20% SoC 时，航程约为 175 公里。 - **储备冗余**：滑跑着陆能力所带来的额外 20% 能量储备未计入基础运营航程测算，可作为额外的安全余量。 ## Mentioned Lilium, Alastair McIntosh, Phoenix, EASA, FAA, EUROCAE, SC-VTOL, Zenlabs, Custom Cells, Energy Assurance ## Video description Lilium's Chief Technology Officer, Alastair McIntosh, provides an update on the program, aircraft design, and certification. [Source](https://www.youtube.com/watch?v=qZ73PftBfFg)

Source quotes

[1:20] Alastair McIntosh: You can build something new that flies, but can't be certified. You can build something that can be certified, but can't be built at scale. You can build something at scale, but can't be sold profitably to a real market.

Original transcript

[0:05] The basic aircraft architecture of wings [0:07] and canard with distributed propulsion [0:10] has been a constant since the early days [0:12] of Lilium. [0:13] As the design details have evolved, so [0:15] is our tool set. [0:17] As well as utilizing commercially [0:18] available software, several in-house [0:21] computational tools have also been [0:23] developed to enable modeling of such [0:25] things as aircraft and engine [0:27] aerodynamics, flight control laws, [0:29] environmental noise, and structural [0:31] loads, and many more besides. This type [0:33] of analysis allows us to quickly iterate [0:36] some of the finer details of our [0:38] architecture. [0:39] Computational analysis is even more [0:41] powerful when calibrated and validated [0:43] by testing. [0:45] Some good examples include wind tunnel [0:46] testing, where our simulations are [0:48] matched by flight conditions in a closed [0:51] environment. [0:52] And of course, real-world flight tests. [0:55] Our technology demonstrator, Phoenix, [0:57] which has been flying since 2019, [1:00] has been about proving out our [1:01] architecture in real flight conditions. [1:04] Recently, we also demonstrated [1:06] transition and flow attachment on the [1:09] main wing, [1:10] where lift is generated by the wings [1:12] rather than the engines. This is a [1:14] significant step forward. It's the most [1:16] difficult maneuver that a VTOL aircraft [1:18] can undertake. [1:20] Transforming the future of regional air [1:22] mobility takes more than just innovative [1:24] technology. You can build something new [1:26] that flies, but can't be certified. You [1:29] can build something that can be [1:31] certified, but can't be built at scale. [1:33] You can build something at scale, [1:35] but can't be sold profitably to a real [1:37] market. So, this requires a very sober [1:40] understanding of the certification [1:42] process, [1:43] which is precisely why we've brought on [1:45] board some of the most proven technical [1:47] leaders from the aerospace industry, [1:49] who've delivered aircraft certification [1:51] programs, and therefore understand the [1:54] rigor of this process deeply. [1:56] Let me touch on some of Lilium's [1:58] certification milestones and why they're [2:00] important. [2:01] The European Union Aviation Safety [2:03] Agency, EASA, is a primary certification [2:06] authority. We're also undertaking a [2:08] concurrent cross-validation with the [2:10] FAA. [2:12] We have participated in several EASA and [2:14] EuroCAE working groups, which has [2:16] contributed to the publishing of SC-VTOL [2:19] certification regulations in 2019. [2:22] This allowed us to begin designing our [2:24] aircraft. In 2020, we received our [2:27] certification basis, the CRI A01, from [2:31] EASA. [2:32] Allowing us to have confidence in the [2:34] specific requirements that our aircraft [2:36] would have to meet. [2:38] In April of this year, we submitted a [2:39] full set of certification means of [2:42] compliance proposals, affirming the [2:44] precise way in which we would [2:45] demonstrate compliance with the safety [2:47] standards. Lastly, the DOA, the design [2:51] organization approval. [2:53] We've now completed our second out of a [2:54] planned four DOA audits, meaning that [2:57] our engineering team is well on the way [2:59] to being fully qualified by EASA to [3:02] design and certify an aircraft. [3:04] An aircraft cannot be certified and [3:06] launched without strict adherence to [3:08] this process from the beginning. [3:10] Otherwise, you only have a prototype. [3:17] Which is why we're excited to say that [3:19] we've successfully conducted a rigorous [3:21] preliminary design review process. [3:24] We've converged on a final design, which [3:26] we have every confidence safely achieves [3:29] the performance our launch customers [3:31] require. It is a package that can be [3:33] successfully certified and can be [3:35] profitably built at scale. [3:37] Let's walk through where we ended up on [3:39] a few of the most important design [3:41] details. [3:42] Let's start with one of our most iconic [3:44] design features, our electric ducted fan [3:46] engines. By simply increasing the [3:48] diameter of the ducted fans by a few [3:50] percent, we were able to reduce the [3:52] number of engines and maintain the total [3:54] thrust and efficiency required. [3:57] This then allowed us to achieve a better [3:59] aerodynamic balance between the main [4:01] wing and the front canard. [4:03] It also means a lower unit cost and a [4:05] lower maintenance cost. And with the [4:07] large diameter fans, we can use better [4:09] acoustic damping in the jet ducts to [4:11] minimize noise. [4:13] With a change to 30 engines, we have [4:15] kept the ratio of three engines to one [4:17] battery pack. [4:18] Therefore, the number of battery packs [4:21] reduces from 12 to 10, but is sized to [4:24] maintain the overall hover power density [4:27] of approximately 2,500 W per kg, but in [4:31] a simplified and lighter weight [4:33] packaging. We also made some subtle [4:35] changes to our duct design and fuselage. [4:38] We've slightly shifted the main wings [4:39] rearward and upward. [4:41] Added winglets to the canard in order to [4:44] make the whole aircraft behave better [4:46] and fly more efficiently. [4:48] This leads to a cruise power density, [4:50] which is 1/10 of the hover power, [4:53] and allows us to improve our range. [4:55] We've added running landing capability, [4:58] which is important to certification [5:00] because it increases reserve range to [5:02] address the jet's ability to deal with [5:04] real-world scenarios [5:06] and be able to divert to alternate [5:08] landing site and perform a short running [5:10] landing, [5:11] which gives us the ability to use more [5:13] cell energy than is otherwise accessible [5:16] in a normal vertical landing. We also [5:19] believe that such a capability, while [5:21] rarely used, will provide additional [5:23] reassurance to our customers. [5:25] Further, in terms of operational safety, [5:28] our 30 engines, large number of flaps, [5:31] independent battery units, and multiple [5:34] flight control computers provide us with [5:36] significant redundancy. We are on track [5:38] to meet the extremely high 10 to the [5:40] minus nine safety standards. [5:43] This means the probability of a [5:44] catastrophic failure is less than or [5:47] equal to one in 1 billion flight hours [5:49] as set by EASA for commercial aircraft [5:52] and for eVTOL. [5:54] Our battery team has been evaluating [5:56] dozens of candidate cells over the last [5:58] several years. [6:00] We have now picked a very capable cell [6:01] design designed by Zenlabs and [6:04] manufactured by Custom Cells that we [6:06] believe provides us with excellent power [6:08] density as well as energy density. The [6:11] battery is exclusive to Lilium within [6:13] our target market and we believe it [6:15] could be one of the highest performance [6:16] cells that is practical for eVTOL in [6:19] existence today. [6:21] The advantage of the Zenlabs cell is its [6:23] combination of both superior specific [6:26] energy [6:27] and specific power capabilities. [6:29] When compared to commercially available [6:31] state-of-the-art cells, the Zenlabs cell [6:34] surpasses both the specific power [6:36] capability of the high power cell and [6:38] the specific energy capability of the [6:40] high energy cell. It is critical to note [6:43] that based on these independent test [6:45] results from Energy Assurance, [6:48] the cell is able to support a high [6:50] specific power of 2,500 W per kilogram [6:54] even down to 20% state of charge. So, [6:58] when we tie all these design elements [6:59] together, we remain on track to meet our [7:01] previously stated physical range of [7:03] approximately 250 km or 155 mi using a [7:08] short vertical takeoff and landing at [7:11] operational empty weight. [7:13] This equates to projected operational [7:15] range of approximately 175 km assuming a [7:20] vertical takeoff at maximum takeoff [7:22] weight and a vertical landing 45 seconds [7:25] duration [7:26] such that 20% state of charge remains [7:29] following the landing. It's worth [7:31] mentioning some important points here [7:33] since these calculations are often [7:35] misinterpreted. [7:36] We use conservative vertical hover phase [7:39] assumptions in our calculations. This [7:41] range doesn't account for the additional [7:43] 20% energy and accessible for reserves [7:46] thanks to the rolling landing, which [7:48] would be supplemental to these figures. [7:50] Lilium's ultimate operating range will [7:52] account for these reserves as well as [7:54] other certification requirements and [7:56] will be confirmed between now and their [7:58] entry into service. [8:00] We believe we've converged on an optimum [8:02] final jet architecture that will meet [8:04] the agreed certification requirements [8:06] and achieve a projected physical range [8:09] of approximately 250 km at launch, which [8:13] is more than enough for our anticipated [8:15] launch routes. [8:16] As battery technology and performance [8:18] improves, we will be able to upgrade the [8:20] aircraft with newer batteries and offer [8:22] even longer range to our customers.