Manned Aircraft Projects

Focus on electrically powered aircraft


The two-seat battery powered aircraft e-Genius has been developed for the practical testing of alternative propulsion and energy storage technologies. e-Genius complements the research focus on electrical flying at the Institute of Aircraft Design (IFB). Instead of the modification of a conventional aircraft, the configuration of e-Genius has been completely re-designed and optimized for the electric propulsion system. The special feature is the big, slowly rotating propeller that is mounted in the vertical stabilizer. The propeller has high propulsion efficiency and made it possible to use a small and light gear. In the current level of development the aircraft has a maximum range of approximately 400 km by using a fuel equivalent of 1.3 l per 100 km. The area behind the side by side sitting pilots offers enough space for different energy storage systems. e-Genius is the most powerful two-seated electric aircraft in the world.

Webseite e-Genius

Icaré 2

Icaré is a solar power-operated high performance aircraft which has been designed for minimum sink rates. The specific features of this aircraft are, among others, a low empty weight and the low cruise speed that remembers to the characteristics of an old-timer. The electric motor (12 kW) is mounted at the vertical stabilizer for an optimum efficiency. A rechargeable battery allows self launching and storage of solar energy. icaré only needs 2 kW of electric power for horizontal flying. The solar panel surface area (more than 20 m2) of the aircraft generates up to 3.5 kW under perfect sunlight conditions. Due to its special design, icaré responds very sensitively to weak thermals. Consequently, a combination of motor and thermal flying is possible in addition to classic motor flying. Until today, icaré has set four official FAI world records.

Icaré 2

Webseite Icaré 2

Current Projects


Fiber Fold Core Integrated Heat Exchanger

Aim of the project

Design, development and functional verification of a novel, structure-integrated skin heat exchanger concept based on a fiber composite foldcore sandwich structure

Project description

Aircraft with modern electrified propulsion systems, especially fuel cells, generate a large amount of unusable heat ("low quality heat", i.e. with a low temperature difference), which results in significantly increased cooling requirements. When using conventional cooling systems, this leads to proportionally larger cooling drag, which has so far severely limited the usability of such powertrains.

The aim of this project is therefore to develop a structurally integrated skin heat exchanger. This will consist of a fiber composite sandwich structure with a folded core. Due to their production using a continuous folding process, these form an open core structure that can be used to transport coolant over the entire size of the element. Structural integrity is ensured by the mechanical properties of the sandwich structure.

The project will investigate various aspects of this novel concept in order to provide a basis for future research. Important work items are:

  • Investigation of the flow through the folded core structure for optimum coolant flow and heat transfer to the surface layers
  • Modification of the fibers and the matrix to achieve high thermal conductivity of the surface layers
  • Numerical investigation of heat transfer, adaptation/new development of existing methods and verification through laboratory tests
  • Integration of the skin heat exchanger into the overall aircraft design and consideration of scalability
  • Construction of a prototype for flight tests with the university's own research aircraft e-Genius to prove functionality. For ease of certification only on a non-load-bearing component will be used in the project, which means that the true potential cannot be fully utilized.
Project partners
  • Institute of Aerospace Thermodynamics (ITLR), University of Stuttgart
  • Institute of Aircraft Design (IFB), University of Stuttgart

Federal Ministry for Economic Affairs and Climate Action (German aviation research program LuFo VI-3)


October 2023 – September 2026


Alexander Albrecht, M.Sc.
Andreas Bender, M.Sc.
Dominik Eisenhut, M.Sc.
Jakob Gugliuzza, M.Sc.
Simon Thissen, M.Sc.

Completed Projects


(Hybrid-)electric powertrain for an airship

Content of the project

The scope of the project is to evaluate possible hybridisation concepts for the airship Zeppelin NT N07, that shall replace the current propulsion system. Especially the use of electric propulsors is being investigated. Different powertrain architectures are set up and compared with regard to criteria such as operating cost, fuel consumption and certifiability. The best suited option is identified and further developed into a complete system, that can be installed and certified in the airship in a future project.

Contribution of the IFB

The IFB has the main responsibility for the hybrid-electric powertrain. That includes researching suitable technologies with a high TRL and high availability, as well as compiling the regulations, guidelines and standards to be fulfilled for the components. Furthermore, the architectures and energy storages in question are defined and created by the IFB. The dimensioning of the powertrains to the performance data of the reference airship is also a task of the IFB, as is the acquisition of all relevant cost data for the components of the hybrid powertrains.

Project partners

ZLT Zeppelin Luftschifftechnik GmbH & Co. KG


Federal Ministry for Economic Affairs and Energy (German aviation research program LuFo VI-1)


October 2020 – March 2023


Dipl.-Ing. Jonas Lay
Andreas Bender, M.Sc.

RS hybrid 1.0

Investigation of optimized hybrid powertrains for aircraft

Content of the project

The scope of the project is the development of an optimized hybrid propulsion system for the aerial platform SK202 developed by Stemme RS, which may be operated as an optionally piloted vehicle (OPV).
The first propulsion chain should be based on a diesel-electric serial hybrid and the second should feature a hydrogen fuel cell as primary energy storage.

As a consequence of the withdrawal of a partner, the specific aircraft could no longer be used and the project was reorganized to widen the use of the developing powertrain for all multiengine aircraft in the 2t range. This is why the architecture of the design was built generic and modular to allow the simple integration of an efficient, powerful and low-emission drive system into the various existing and future aircraft to-be. The newly defined output of the project is a power train demonstrator, that will be used for testing and later adaption and integration into a manned serial CS-23 aircraft.

Contribution of the IFB

Before the reorganization, the institute was responsible for the flight performance analysis, the layout and sizing of the hybrid system and the corresponding system architecture in terms of power distribution and means of control. Furthermore, the integration aspects and implications for all subsystems like the propulsors and batteries were investigated.

After the reorganization, the IFB focused on the control scheme and the interactions of the different subsystems. A key aspect of the multi engine setup calls for a dedicated safety and redundancy management. Besides the software development, the required components for the demonstrator were assessed, acquired and integrated. A flightworthy battery based on Li-Ion cells was developed and built twice. Furthermore, the initial operation and bench tests of the iron bird are conducted by the IFB in cooperation with all partners.

Project partners
  • Reiner Stemme Utility Air Systems GmbH
  • Steinbeis Flugzeug- und Leichtbau GmbH
  • APUS Aeronautical Engineering GmbH
  • Siemens eAircraft / Rolls-Royce Electrical (ass. Partner)
  • Continental Aerospace Technologies GmbH (ass. Partner)

Federal Ministry for Economic Affairs and Energy (German aviation research program LuFo V-2)


January 2016 - October 2021


Dipl.-Ing. Jonas Lay
Andreas Bender, M.Sc.


Team lead

Andreas Bender


Research Associate, Team lead Manned aircraft projects

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