In the Urban Rescue project (2020-2024), the German Aerospace Center (DLR) designed, produced and crash-tested a two-seat eVTOL rotorcraft for use in emergency medical and urban rescue operations. It was designed as a flying medical response unit with a hybrid-electric system and a crash-tested carbon fiber-reinforced composite structure.

The emphasis on safety includes features such as energy-absorbing components and a reinforced cabin, proven effective in high-impact crash simulations. Built using low-waste advanced composites manufacturing and developed entirely digitally, this aircraft sets a new standard for safe and efficient emergency air mobility.

The project was led by the DLR Institute of Structures and Design in Stuttgart and included the following departments:

• Component Design and Manufacturing Technologies and Structural Integrity
• Automation and Quality Assurance in Production Technology at the Augsburg site, which is also the Augsburg Center for Lightweight Production Technology (ZLP).

The eVTOL design focused in particular on the composite underbody structure, and was cooperatively developed, designed, manufactured as a demonstrator and crash tested in a continuous interdisciplinary exchange. Project management and production was in Augsburg and the tests and the final crash test took place in Stuttgart.

Crashworthy eVTOL design focused on underbody structure

In parallel to the classic structural design for developing an airframe, a crashworthy design and the consideration of manufacturing and production aspects were also implemented and analyzed in all design phases. The crash design developed includes the airframe structure, safe battery integration and crash-absorbing seats. The aim of linking structural design, crash design and production was to develop an underbody that combines an optimized, crash-safe structural design with innovative production processes.

Manufacturing using multiple composite technologies

A demonstrator structure of the medical personnel deployment eVTOL, comprising the central underbody structure and the two main frames, was manufactured at the ZLP in Augsburg in accordance with the results of the design process. Various fiber-reinforced composite technologies were used to produce the demonstrator structure including dry fiber placement, resin transfer molding (RTM) and the out-of-autoclave (OOA) prepreg. The processes were selected depending on the respective structural requirements and served to realize reliable, lightweight component production.

Full-scale crash test validates composite underbody safety

The demonstrator with crash-optimized seats and crash-proof battery integration was installed in a test rig structure at the institute in Stuttgart. The crash concept was successfully proven in a full-scale crash test under realistic, combined horizontal-vertical impact conditions (v_z = 7.4 m/s, v_x = 4.3 m/s). The findings of the Urban Rescue project will be incorporated into future research projects on the design of eVTOL and helicopter structures.