欧洲的VTOL现实检验：从空中出租车到任务驱动型飞机

Europe’s eVTOL sector is shifting from urban air mobility towards targeted applications such as cargo, medical evacuation and defence, with hybrid-electric architectures emerging for longer-range missions. The challenge now is to combine range and payload with the right materials, certification requirements and industrial-scale production.

A major obstacle to market acceptance of eVTOLs is definitively the propulsion system. “Vertical take-off requires high power, and the performance of lithium-ion batteries is not yet sufficient “, Dipl.-Ing. Karl Michael Käser, CEO of Kasaero GmbH explains. The German engineering company, located in Böblingen, supports customers all in one place in aircraft and lightweight design, composite technology, aerodynamics, all the way to certification. The ratio of development costs for the composite airframe compared to power train and flight control costs are for eVTOL’s approximately 1:20 or 1:30, Käser clarifies. Due to aerodynamic factors, their energy consumption is significantly higher than that of conventional aircraft, and they have greater system complexity, except that they do not require a runway. This also explains the shift towards applications in the military and defence sectors, where rescue operations often take place in hard-to-reach and rugged terrain.

The mission determines the technology

Germany’s ERC System illustrates this development. Unveiled at ILA 2026, its Victor U250 is an uncrewed hybrid-electric heavy-lift VTOL designed for military resupply and critical logistics. It targets a payload of 250 kg over more than 300 km at a cruise speed of 250 km/h, with first series deliveries planned for 2028.

ERC, Rheinmetall and North Rhine-Westphalia have signed an MoU aimed at establishing Victor production and associated supply chains in NRW, Germany. The objective explicitly includes market launch and industrialisation. ERC has shifted its focus away from the originally targeted air taxi market in favor of applications in which vertical take-off, payload and infrastructure-independent operation provide a clearly defined operational benefit.

Bundeswehr is increasingly relying on unmanned systems in its military medical services. It has recently commissioned Avilus GmbH to carry out the innovation project for the Grille X4 rescue drone. It is a recent example that battery-electric propulsion has not become irrelevant. Avilus’ uncrewed Grille X4 uses a fully electric powertrain and is designed primarily for medical evacuation and logistics.

The payload is up to 175 kg over around 50 km. Grille completed its maiden flight in June and is about to go into repeatable pre-series product. Although the exact material composition is not disclosed for reasons of military secrecy, the structure is most likely a monocoque design that utilizes fibre-reinforced composites. “If the aircraft is not supposed to be detected by radar, fibreglass-reinforced plastic is more likely to be used; if carbon fibre is used, special radar-absorbing shielding is required”, Steffen Geinitz, senior business developer at Fraunhofer IGCV explains.

“The technology used depends on the planned production volume. Fibre-reinforced thermoplastics can be processed using established process routes that allow for higher production rates than those achievable with thermoset processes. Drones are going to be vital in the future, especially in the field of defence”, he assures. In the Future Combat Air System (FCAS) and in subsequent concepts such as “Team Gen 6,” drones play a pivotal and absolutely central role.

The contrast is revealing battery-electric propulsion can serve short-range, clearly defined missions, while hybrid-electric architectures can address applications requiring substantially greater range and payload.

Costly certification might become a problem

Minimum weight alone is no longer sufficient. Cargo and military aircraft must equally meet requirements for durability, damage tolerance, repairability and operational robustness. From a manufacturer’s perspective Dr. David Löbl, CEO, ERC System points out: “On a VTOL aircraft, every kilogram counts – that has not changed. But we look at weight much more as a trade-off now: if saving one kilogram makes the part significantly more expensive to build or repair, it is not worth it. Composite raw materials are getting harder to source in Europe. Going back to sheet-metal aircraft because the industry cannot manage its composites supply chain – this cannot be the answer.” While prototypes are usually manufactured using fibre-reinforced composite technology, strict aviation standards and scalability determine the choice of manufacturing technology and materials, according to Käser. “Since the properties of composites are created only through the combination of different materials, the complexity of structural certification results in high costs.”

This raises a central materials question: will conventional thermoset CFRP remain dominant, or will faster processes, thermoplastic composites and more integrated structural concepts gain importance as production increases? The decisive question is shifting from whether an aircraft can take off vertically on batteries to which propulsion, structure and manufacturing concept best serves a viable mission. ERC’s Victor and Avilus’ Grille demonstrate two very different answers.

Heading photo: Courtesy of Joby Aviation. (c) Joby Aero, Inc.

Editorial Contributor, Isa Hofmann