Emis­sion-free flight

The objective has now been set in Germany and Europe, with the aim of achieving climate neutrality in the economy and society. This is how it is worded in the EU's 'Green Deal'. The consequences of climate change also compel us to strive towards climate-neutral air transport, as this sector is responsible for 3.5 percent of global warming. New technologies are needed to ensure global mobility in the future. With 25 institutes and facilities active in aeronautics research, DLR is driving this change forward with sustainable technologies for environmentally compatible air transport. Expertise from DLR's space, energy and transport research programmes is also playing an important role in this.

DLR's ultimate vision is zero-emission air transport. Achieving the climate targets that have been established will require a disruptive approach. Aircraft and air transport must be considered as a complete system. DLR is one of the few research institutions in the world with the capability to simultaneously equip aircraft with new propulsion systems, record their emissions and model the resulting climate impacts within the context of the global air transport system. This systems expertise places DLR in the role of architect. From fundamental research through to applications, DLR works in close coordination and collaboration with the aircraft industry and the air transport sector.

Efficient aircraft configurations with an optimised mix of propulsion technologies

In concrete terms, the energy requirement of new aircraft must be reduced by at least half by 2050. In order to meet this target, these will have to become significantly lighter and more aerodynamically efficient, in combination with the introduction of innovative flight control and sensor systems. Efficient aircraft configurations will require an intelligent mix of alternative propulsion system concepts. In future, small and regional aircraft will be able to take off using battery or hybrid-electric systems, while medium-haul aircraft will be capable of flying using direct hydrogen combustion or fuel cells. On long-haul routes, aircraft will use Sustainable Aviation Fuel (SAF) in combination with highly efficient turbines.

Climate-optimised flight routes offer important possibilities for savings, and these can be harnessed quickly and for all aircraft. This is especially important given that two-thirds of the climate impacts of air transport are due to non-carbon-dioxide effects. Contrails play a significant role in this. They occur in specific places and are thus a key area of focus for routing.

The digitalisation of air transport is an essential tool in this comprehensive transformation. Optimised flight routes rely on complex computer simulations. New aeronautics technologies will make their initial flights as digital twins on a computer before being tested in the real world. Many of them have to be researched from the fundamentals, tested in practice and finally certified. DLR is in prime position to do this, with its research aircraft, wind tunnels, propulsion demonstrators and supercomputers.

In 2020, DLR published the white paper 'Zero Emission Aviation' with the German Aerospace Industries Association. DLR is currently working on a Zero Emissions strategy for aeronautics research.