Is it possible to steal an airplane?

Will emission-free flying be possible soon?

It is still just a vision of the electric flight of the future - but judging by this, Josef Kallo already has precise ideas.

There is a good chance that in ten years the first prototypes with up to 80 passengers on short and sometimes medium-haul routes will be largely emission-free, says the renowned researcher at the German Aerospace Center (DLR) in Stuttgart. In their search for the aircraft of the future, scientists and engineers are relying on alternative drive variants. Kallo relies on large amounts of hydrogen, which are supposed to generate so much electrical energy in fuel cells that passenger planes take off, fly and land with it.

E-aircraft will be ready for the market in around 20 years

Kallo has been researching fuel cells since 1998, and has been researching fuel cells specifically since 2006. The 46-year-old sees his team as an international leader in this segment and says that as things stand at the moment, this type of electric drive will be ready for the market and series production for smaller aircraft around 2030. Then it is conceivable that airlines will complete some of their flights with hydrogen. "The technology for this is basically already available today; it now only has to be transferred to larger aircraft."

However, this not only requires a lot of effort, but also a lot of money. The technical development, the production and ultimately the approval of such planes are extremely expensive and take a long time, says Kallo, who is hoping for significant investments from the industry. If everything interlocks, it will take a good 15 years before aircraft with up to 80 passengers on board at speeds between 550 and 600 kilometers per hour and at distances of up to 2,000 kilometers are also visible in scheduled traffic.

Such machines could then take over feeder flights to hubs such as Frankfurt Airport, and the establishment of regional flight networks between smaller airports is also conceivable. The bottom line could be a significant decrease in emissions.

Planes could slow down

The search for alternative forms of propulsion is currently a priority for airlines and aircraft manufacturers like never before. But unlike in road traffic, there has so far been a lack of economically viable, low-emission drive alternatives when flying - visions like that of Kallo are more audible than before in view of the spreading shame of flight. The problem: No previously known approach has convinced the industry in the long term, most likely different types of synthetic fuels are still considered to be the beacons of hope.

Kallo's approach also has disadvantages, especially economic ones: the performance of fuel cells falls significantly behind that of conventional fuel drives. In other words, if airliners are to fly more than 2,000 kilometers, either the number of passengers would have to be reduced or the speed would have to be throttled, presumably both. For large airlines, which often transport significantly more people from A to B, hardly profitable. When asked, a Lufthansa spokesman said: "Around 80 percent of flights are on routes longer than 1,500 kilometers. Today and for the foreseeable future, there are no equivalent and fast alternatives and no new drive technologies."

The extent to which aircraft powered by hydrogen and fuel cells will prevail on the market will also largely depend on the extent to which the performance of the systems is increased. The market for this is only just emerging, says Kallo, who says he has received funding for his research from the Federal Ministry of Economics and Transport, but also from large industrial groups. "The performance of the systems has doubled in the last three years alone," he reports. The further development is difficult to predict. In short: if even more powerful systems were to come onto the market, more passengers could be transported further at higher speeds.

Hydrogen has not yet been a suitable drive

Those who rely on hydrogen planes, however, have to plan for powerful tanks because of the lower energy density of hydrogen compared to kerosene. "The tanks would therefore have to be three times the size of a conventional aircraft. That would also require larger aircraft, airport terminals and runways," says Lufthansa. In addition, the storage of large hydrogen reserves is complex and energy-intensive. One sees aviation "still far away" from hydrogen propulsion.

The British company Rolls-Royce, which manufactures propulsion systems and recently bought the electric flight unit from Siemens, is more optimistic. Systems like the one described by Kallo are conceivable at least in regional air traffic by 2030. For example, they are working with the aircraft manufacturer Airbus on the development of e-planes.

Synthetic fuel is currently still too expensive

The issue of propulsion in air traffic naturally also has a political component. Politicians are under pressure, driven by social movements such as Fridays for Future - and are now in turn putting pressure on the industry. So far, however, little has happened, which is also due to the fact that only small amounts of synthetic fuel are available at very high prices. Lufthansa complains that such fuels are currently three times as expensive as conventional kerosene. Nevertheless, they consider synthetically produced fuels to be "the only real alternative" to "neutralize" emissions in aviation.


Kallo will therefore have to continue to persuade him so that his vision of flying with fuel cell propulsion becomes more than a pure niche product. Especially since the whole thing would only be climate-neutral if the large amounts of hydrogen come entirely from renewable energies. In the future, the scientist is also relying on his colleagues from the automotive industry, where the development of drives with fuel cells and hydrogen is just gaining momentum. Hundreds of millions of euros are currently being spent there, says Kallo - aviation can only benefit from the development of such high-performance systems.

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