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Drag reduction technologies in aircraft design are the key enabler for reducing emissions and for sustainable growth of commercial aviation. Laminar wing technologies promise a significant benefit by drag reduction and are therefore under investigation in various European projects. However, of the established moveable concepts and high-lift systems, thus far most do not cope with the requirements for natural laminar flow wings. To this aim new leading edge high-lift systems have been the focus of research activities in the last five years. Such leading edge devices investigated in projects include a laminar flow-compatible Kruger flap [1] and the Droop Nose concept [2, 3] and these can be considered as alternatives to the conventional slat. Hybrid laminar flow concepts are also under investigation at several research institutes in Europe [4].

Demonstrators and research projects about electric aircraft taxi systems testify the current interest in low- or zero-emission ground propulsion technologies to lower the overall fuel consumption and emissions of commercial flights. Electric motors fitted in the main landing gears are one of the most promising layouts for these systems especially for narrow-body commercial aircraft. From a control theory point of view, the aircraft on ground becomes an over-actuated plant through adoption of this technology, i.e. a commanded ground trajectory can be reached through different combinations of actuator efforts. A strategy is required to choose the most suitable of these combinations in order to reach the best efficiency. This work aims to investigate a strategy for an optimal control allocation during path-following of prescribed ground trajectories.

A number of promising technologies to perform ground movements without main engines are currently being researched. Notably, onboard ground propulsion systems have been proposed featuring electric motors in the landing gear. While such on-board systems will help save fuel and avoid emissions while on ground, they add significant weight to the aircraft, which has an impact on the performances in flight. A tool to assess the global benefits in terms of fuel consumption and emissions is presented in this work. A concept of an aircraft-integrated ground propulsion system is firstly considered and its performances and weights are determined, assuming the Auxiliary Power Unit or a zero-emission device like a fuel-cell as power source for the system. Afterwards, a model of the propulsion system integrated into an object-oriented, mid-sized aircraft model is generated, capable of precisely simulating a whole aircraft mission.

For thermal cabin control of commercial aircraft, the cabin is usually divided into a small number of temperature zones. Each zone features its own air supply pipe. The necessary installation space for ducting increases significantly with the number of zones. This requires the number of temperature zones to be low. Factors such as seating layout, galley placement and passenger density result in deviations in heat flux throughout the cabin. These deviations cannot be compensated by the control system, if they occur within the same temperature zone. This work presents a novel temperature regulation concept based on local mixing. In this concept, two main ducts span the complete cabin length, and provide moderately warm and cold air. At each temperature zone, cabin supply air is locally mixed using butterfly valves. In this way, the number of temperature zones can be individually scaled up without any additional ducting, only requiring additional valves for each temperature zone.