Key technologies for the hybrid-electric Silent Air Taxi are being developed in collaboration with numerous institutes at RWTH Aachen University and several industrial partners. In this process, both the individual systems and their components as well as higher-level issues of integration and safety are being considered from the very beginning.


The Silent Air Taxi, which is being developed in the vicinity of RWTH Aachen University, is intended to be an environmentally friendly and low-noise small aircraft connecting small airfields in a commercial transport service, thus establishing a new, cost-effective and safe air mobility concept. To achieve these goals, several technological innovations must be developed and integrated into the aircraft. The E-SATstart research project is dedicated precisely to these innovative system technologies. Besides the Institute of Aerospace Systems, the institutes IST, FSD, SLA, IEM and ITA of RWTH Aachen as well as the Fraunhofer IPT take part in the project. MTU, Liebherr, Engiro, IMA and CirQua are involved as industry partners.

Minimizing noise emissions by using a ducted prop, a propeller encased in a nacelle, creates the basis for the widespread use of the Silent Air Taxi. For this purpose, an aeroacoustic optimization of the ducted propeller will be carried out, taking into account aerodynamic and structural-mechanical boundary conditions, followed by experimental validation on a test rig. A further reduction of noise emissions as well as fuel consumption will be achieved by using an electro-hybrid propulsion system integrated in the fuselage, which will be analyzed and evaluated. To map aviation-specific influences on the electric powertrain, the fault-critical and safety-relevant requirements and components are determined, physical cause-effect relationships and in-depth models are derived and taken into account for the development of the electric components, which are finally validated on a test bench. The specification, design and development of the flight control system is also part of the project and will be validated by hardware in the loop tests. An application-optimized actuator design will be developed after the actuator specification.

The Institute of Aerospace Systems is participating in the area of aeroservoelasticity and system safety analysis. The new aircraft design will go beyond the current limits by developing a framework that optimizes the wing with respect to aerodynamic shape, structural sizing and control system simultaneously. The goal of this framework is to maximize the endurance under stress and maneuverability constraints of the aircraft. In parallel, the process route for the cost-effective production of the wing will be developed and subsequently applied to a demonstrator. The demonstrator will be used to validate the structural-mechanical optimization methodology. For the system safety analysis, a model-based safety analysis method will be developed, enabling modeling and analysis of the safety properties of different systems early in an ongoing design process. This will support architecture decisions and reduce the cost of re-evaluation in case of design changes.