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.

Background articles

News on the topic


Hy4 – the world's first four-seat pas­sen­ger air­craft with hy­dro­gen fu­el cell tech­nol­o­gy and elec­tric propul­sion
In this manner, the Hy4 marks a milestone. It is a hybrid aircraft with PEM fuel cells and high-performance lithium batteries to support take-off and altitude changes.
Electric high-flyer for 19 passengers
The configuration represents an electric high-flyer with gas turbines for cruise flight. The conceptual study includes four electric propellers and two gas turbines integrated into the inner nacelles parallel to the electric motors. Batteries are in the landing gear nacelles on the fuselage.
Conceptual study of a hybrid electric 19-seater
DLR and Bauhaus Luftfahrt analysed the possibilities and potentials of hybrid-electric 19-seaters. The results show that electric drives can be used to save CO 2 for short distances of up to 350 km that are frequently flown in this class.


Con­cep­tu­al study of a hy­brid elec­tric re­gion­al air­craft
The conceptual study presents a regional aircraft with distributed electric drives at the leading edges of the wings, which can improve efficiency and reduce energy consumption. Together with industrial partners, DLR is investigating the effects of distributing the propulsion masses over the entire aircraft.
Hybrid electric short-haul aircraft
An electrically driven fan at the rear of the aircraft ingests the fuselage boundary layer, thereby improving propulsion efficiency. The research work is being carried out in the ADEC (Advanced Engine and Aircraft Configuration) project as part of the European Clean Sky 2 programme.
Fly­ing with hy­dro­gen
Hy4 paves the way for climate-neutral passenger aircraft.
Elec­tric re­gion­al air­craft with dis­tribut­ed propul­sion
Elec­tric re­gion­al air­craft with dis­tribut­ed propul­sion
Ex­haust gas mea­sure­ments dur­ing for­ma­tion flight
Behind the DC-8, which is using biofuel, scientists on board the DLR Falcon measure the exhaust gas composition.




Falk Dambowsky

Head of Media Relations, Editor
German Aerospace Center (DLR)
Corporate Communications
Linder Höhe, 51147 Cologne
Tel: +49 2203 601-3959