In the beginning it was the Wright brothers in 1903. From there aviation was all projected into a technological run-up towards the search for speed, but also for safety and comfort in the transport of goods and people. At this point, also for the environmental issues that have definitely moved from the public debate to the production and development sector, the new technologies are definitely working around the issues related to the engines and energies that move planes. It has been a few months since the first hydrogen aircraft with fuel cells and electric motors, built on the basis of a commercial model, flew for a few minutes taking off from Cranfield, England, home of the ZeroAvia research facility. Around the same time, Airbus announced details of three projects it is working on, all powered by hydrogen and with the aim of having them operational by 2035. In turn, United Airlines announced that it has signed an agreement. commercial for the purchase of aircraft called Overture from Boom Supersonic, aircraft optimized to run on 100% sustainable aviation fuel. The current technological focus undoubtedly responds to the idea of reducing the environmental impact of aviation. According to the International Energy Agency, the carbon dioxide emissions of aviation have taken off, to stay on the subject, reaching a figure that touches the gigatonne in 2019, something like 2.8% of the global CO2 emissions produced by the burning of fossil fuels. WWF also describes aviation as one of the fastest growing sources of greenhouse gas emissions, and air travel is currently the most carbon-intensive activity an individual can do. According to the Air transport action group, for each passenger, flying produces 285 grams of carbon dioxide per kilometer traveled.The real engine of the technology revolves around the propulsion system. In this sense, MIT in Boston is working on a system that could eliminate 95 percent of CO2 emissions. In this case, the propulsion design would resemble a modern diesel engine that cleans up emissions before the exhaust gases are expelled. And, while MIT and the Wuhan Institute of Technological Sciences compete on plasma-engine aircraft, the Austrian startup Volare GmbH and the Vienna University of Technology are developing electrically-powered and eco-sustainable aircraft for medium-range routes. An aircraft “designed to combine the advantages of an airplane with those of a helicopter”.