Flight of the future: The bold dream of the German aircraft inventors

So this is where the clean future of aviation is being created: In an open-plan office in Munich’s Obergiesing district, 25 employees are concentrating on their monitors. A room further on, a 3D printer is printing quietly. Ivor van Dartel, co-founder of Vaeridion, stands next to it and pushes an elongated battery into the cutout of a carbon aircraft wing. “We invented that,” says the former Airbus developer proudly.

The batteries are in individual boxes: If a cell catches fire, the fire remains isolated and all other segments continue to work. Safety is the top priority in the aviation industry. This is especially true for their revolutionaries. In a few years, one or two pilots will transport up to seven passengers through the air in the new aircraft from Munich, up to 500 kilometers away. Electric, clean, quiet.

Three percent of emissions

The engineers call their flying object Microliner. It should do much more than the visionary, drone-like air taxis for inner-city traffic. It is similar to a conventional fixed-wing aircraft – only with an electric motor. More precisely: two of them that independently drive the same propeller. This is also for safety and is a Vaeridion invention.

The problem that the company wants to solve can be seen and heard just half an hour’s drive away: from the major Franz Josef Strauss airport, scheduled jets for America, Asia or Arabia take off every minute – including the gigantic, but technically already outdated Airbus A380. Its four engines burn 32 tons of kerosene every hour, a nightmare for the climate. Private jets often take off between the large passenger planes. Overall, global aviation only causes around three percent of all carbon dioxide emissions. However, the contrails that jets draw in the sky at a height of ten kilometers are particularly harmful to the climate: they create cirrus clouds that increase the greenhouse effect.

After the governments of the world have watched this for a long time, many of them are now demanding that aviation also make a contribution to combating global warming:

• From next year, fuel for commercial aircraft in the EU must contain at least two percent climate-neutral fuel, so-called SAF (Sustainable Aviation Fuel – sustainable aviation fuel). This proportion is expected to increase to six percent in 2030, 20 percent in 2035, and finally to 70 percent in 2050.
• Sweden and Denmark will require emission-free drives for short journeys from 2030.
• Norway requires electric drives for short journeys from 2040. Cross-border connections are also affected, including Lufthansa, for example.
• France bans short-haul flights for distances that a train can cover in under two and a half hours.
• Singapore, a hub for a global airline, requires a SAF share of one percent for flights departing from 2026 and up to five percent from 2030.

SAFs are the method of choice to allow the armada of existing jets to fly in at least a somewhat climate-friendly manner. The e-fuel in the air theoretically releases up to 80 percent less CO₂. It is mixed with normal kerosene and has so far mostly been obtained from biomass. In a few years, the “Power to Liquid” process is expected to deliver large quantities of green fuel. It uses green energy, mainly
Solar powerto obtain fuel from water and carbon dioxide. Electrolysis splits water into hydrogen and oxygen, and the carbon dioxide can be captured at the chimneys of large emitters.

In Austria, three kilometers northwest of Vienna Airport, in the town of Schwechat, towers of the oil company OMV rise into the sky. For laypeople, the plant is no different from a normal refinery, but it produces the valuable admixture: sustainable aviation fuel flows from here directly to the airport via a pipeline. OMV supplies up to 700 tons of SAF from used cooking oil every year to airlines such as Lufthansa, KLM and Wizz Air. Soon it will be much more, assures Martijn vanKoten, OMV’s board member for fuel and raw materials. He says: “SAF is the most important pillar for minimizing carbon dioxide in aviation.” The material is still in short supply and unfortunately it is up to three times more expensive than kerosene.

60 million tons of fossil fuel

The eco-fuel is admitted according to a certificate system. If a passenger books the corresponding air conditioning option for their ticket from New York to Frankfurt, passenger aircraft with a slightly increased SAF share will take off from Vienna-Schwechat. Voluntary donations from passengers who want to protect the climate and their conscience will not be enough. In Europe alone, airplanes are currently refueling with 60 million tons of fossil fuel every year, and the number of passengers is increasing again.

In order to move closer to the EU’s 70 percent target, Airbus and Total Energies have agreed on an agreement for the supply and research of clean jet fuel. OMV and Microsoft want to get business airlines clean. Virgin Atlantic, the airline owned by British entrepreneur Richard Branson, launched an important test flight. A Boeing 787 burned exclusively SAF in its two Rolls-Royce engines between London and New York. It was a so-called ferry tour, without passengers or freight.

Airbus is apparently working on a jet that would run particularly well on eco-fuel, an efficient successor to its successful A320 model. According to industry rumors, the European manufacturer is considering a special engine technology from the engine manufacturer CFM called RISE for the drive. Its principle is similar to a jet turbine without a housing. The manufacturer promises optimization to 100 percent sustainable fuel and a 20 percent reduction in consumption.

Reduce to zero

The next step towards sustainable aviation would be even bigger and more radical. Several companies are researching hydrogen propulsion. It would be sparkling clean in its “green” version if it was produced using solar or wind energy. Hydrogen could either be burned directly in engines or converted into electricity using onboard fuel cells. “Hydrogen can reduce CO₂ emissions in aviation to zero and is particularly suitable for regional and short-haul aircraft in the medium term,” says Markus Fischer, Head of Aviation at the German Aerospace Center.

Last September, the small Stuttgart company H2Fly successfully launched its experimental aircraft with liquid hydrogen and fuel cells over Slovenia for the EU project HEAVEN. The large Airbus group is also working on the technology. Its ZEROe concept is expected to be ready for series production by 2035. That’s an ambitious and arguably unlikely timeline.

“There are still many unresolved problems,” says DLR expert Fischer. The safety issues, the large volume and weight of the components required novel flight concepts, complex tank technologies and an innovative system architecture. It is also unclear when and whether enough green hydrogen will come onto the market.

E-planes will probably be on the market faster than hydrogen aircraft

As an alternative for regional and short-haul routes, battery-powered electric aircraft will probably be available more quickly. In addition to Vaeridion in Munich, many other start-ups are working on their models. The Slovenian Pipistrel VelisElectro aircraft has been proving the concept’s suitability for everyday use since 2020. The young Swedish company Heart Aerospace is currently developing one of the largest electric planes to date: the ES-30 with 30 seats.

In two hangars at the former Säve airport near Gothenburg there is still only a metal frame on a 1:1 scale and a demo version of the planned interior. But the principle of the clean regional aircraft has been designed: an internal combustion engine in the rear charges the batteries when necessary, thus doubling the 200 kilometer range of the four 750 kilowatt electric propellers. So it is a hybrid system. It’s been well received by some airlines: Air Canada and the regional airline Mesa from Phoenix have ordered machines. In addition to the short range, the slow charging of the enormous amounts of energy required is a high hurdle for the electric vehicles in the sky.

During the so-called turnaround between landing and the next take-off, regional airlines usually only have 50 minutes. Even technologies like the MCS megawatt charging system are reaching their limits. It pushes electricity into the batteries at up to 3.75 megawatts, more than ten times as fast as the currently fastest electric car batteries. Removable batteries, such as those developed by engine giant Rolls-Royce, could help. The young industry must hope for further progress in battery technology. Hybrid aircraft are probably only an interim solution.

Short-haul tickets with e-flight could drop to the level of train tickets

The author of this article learned that the fascination of electric drives in the air can be even greater than on the road during a test run in the Heart Aerospace simulator. Push the two thrust levers forward and the electric plane glides onto the runway with a quiet whirring sound. After a short, powerful acceleration to 170 km/h, it takes off. He reliably follows the commands on the control horn before landing safely again.

The Stromer differs from a conventional regional jet or a turboprop aircraft in two main ways: firstly, the almost complete absence of engine noise. Passengers and crew will appreciate this, as will residents in departure and arrival paths. The second difference could revolutionize commercial aviation: thanks to the high torque of its engines and its powerful acceleration, the Heart ES-30 can cover a runway 750 meters long.

This corresponds to the runway of a better sports airfield. This would mean that they would no longer have to rely on large, expensive airports. Completely new connections would be possible and ticket prices could fall. Vaeridion co-founder van Dartel also raves about the financial benefits. “The costs per seat of an electric nine-seater are equivalent to those of a conventional aircraft with 40 seats,” he calculates. While long-haul flights are likely to become more expensive due to high taxes or costly SAF additives, prices for electric planes on short-haul flights could fall to the level of train tickets.

Short-haul comeback

DLR man Markus Fischer predicts a comeback of short-distance flights if they can be carried out cleanly and economically: “With low-emission engines, short-haul connections that have been discontinued could be resumed and smaller airports could also be integrated into the route network.” On top of that, many people are calculating AeroFans, traveling by air would be better accepted again by society. The bold vision: Flying could even become more environmentally friendly than traveling by train.

If one day both means of transport are emission-free, other ecological aspects will come to the fore. For example, land consumption. Aviation advocates argue that aircraft only need their airports and nothing in between. New railway lines, on the other hand, cut a 30 meter wide path into the landscape, require bridge constructions across valleys and pierce mountains. There is probably no alternative to flying when traveling between continents. And it’s hard to imagine doing without it: “People want to continue to fly, but in a sustainable way,” muses OMV manager van Koten. “It’s a piece of joie de vivre.”

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