Flying without increasing your carbon footprint is a goal within reach. Airbus and Embraer are working hard to get the first passengers on board in 2035. Teams of systems engineers from Airbus are currently working on a propulsion system capable of converting liquid hydrogen into electricity and running an engine and much less polluting than current engines. The heart of the system consists of hydrogen fuel cells.

Image credit © by futura-sciences, The A380 Plus, an improved version.

By 2026, Airbus, in collaboration with the engine manufacturer CFM International, intends to install on the A380 its prototype "propulsion system" which could be either a fuel cell supplying an electric motor, or a gas turbine converting Hydrogen instead of kerosene. Its use in commercial aviation still poses many technical challenges, in particular the need to store this gas at very low temperature (-235°C) and high pressure in spherical tanks. In addition, hydrogen will put a strain on mechanical parts, as it burns at a much higher temperature. Another challenge for a sector subject to drastic certification and security rules.

Fuel cells emit only water when they turn hydrogen into electricity, but the power of the propeller motors they power is limited. A gas turbine fueled by hydrogen is more powerful, but it is also more polluting, because the combustion of hydrogen emits nitrogen oxides, which contribute to climate change. Both technologies are being evaluated to determine their potential for aviation, and a choice will be made based on the results.

Airbus plans to test these systems in the air from 2026 to 2028, under real flight conditions. Once the technology is chosen, Airbus will launch in 2028 the design of a real hydrogen plane, with 100 passengers and a range of around 2,000 km, characteristics that the company's engineers consider realistic with current technology. If all goes according to plan, Airbus' first hydrogen-powered plane should enter service in 2035.

Brazilian manufacturer Embraer also plans to launch its first hydrogen planes in 2035, according to what the company revealed this week, but these will be smaller, with 19 to 30 seats, and a more limited range, around 370 km.

Image credit © by planespotters, N772ET Boeing Boeing 777-2J6.

Boeing has also invested in hydrogen (its small two-seater demonstrator flew for the first time in 2008). For now, however, the American company has still not announced any aircraft, instead focusing on sustainable aviation fuels (better known by the English acronym SAF, better known by the English acronym SAF, sustainable aviation fuels) to reduce emissions. These synthetic fuels (which are also part of the decarbonization strategy of other manufacturers) can be produced, for example, from used cooking oils, or CO2 emitted by factories; this CO2 is captured at the source, in industrial chimneys, and chemically recombined with energy (from hydrogen) to become fuel again.

For its part, Safran is seeking to establish itself as the centerpiece of carbon-free aeronautics. To do this, the equipment manufacturer has chosen to join forces with several "business units" at Thales. Strategic takeovers that will enable it to assert its leading position, particularly in the energy performance segment for civil aviation, but also as a supplier of high-tech systems for military aircraft.

The company was best known for its participation in the energy savings induced by improving the energy efficiency of its reactors. It is largely to him that we owe the fact that the plane today consumes just over 2 l/km per passenger, or as much as an average car with four people on board.

But Safran's strategy goes further than engine progress. Now, the equipment manufacturer is working to reduce the weight of aircraft by replacing physical equipment with digital signals within the cabins.

Air travel is also converting to digitization, moving from atoms to electrons…replacing matter with digital information in the microcosm of an airplane cabin. Replacing dozens of control cables and hydraulic circuits with simple electric wires connected to sensors and actuators makes it possible to lighten the cabins by several hundred kilograms. Over the lifetime of a device, the savings in energy and CO2 emissions are considerable.

Image credit © by gettyimages, Engineers working with aircraft in repair hangar.

Aviation is expected to become decarbonized by 2050. Several possible technical and technological solutions are currently being studied.

The "Fly by wire" (numerical control) has undoubtedly been the main revolution of the last 20 years. Inaugurated by Airbus before being adopted by Boeing, it broke the taboo of direct control that tied pilots' hands to control surfaces by replacing them with digital controls. It is now the new standard in modern aircraft design. The digital path will become more and more important in the total added value of airplanes and helicopters by producing considerable savings in energy and CO2 emissions.

Creating a hydrogen plane isn't the biggest challenge, rather it's the other ones alongside that can be difficult to place, like setting up the ecosystem needed to power airports with hydrogen. It will be necessary to refuel these new planes and above all to ensure the proper production of this hydrogen. At present, it would be difficult to supply the airline industry with green hydrogen in large quantities, confirms the FlyZero program.

As an aside, Mr. Mehran Ebrahimi, professor in the Department of Management and Technology of the ESG of UQAM in Canada, following work comparing the greenhouse gas emissions generated by the aeronautical industry and those produced by the technology sector, it appears that while civil aviation is responsible for 2% of the planet's carbon emissions, information technologies are responsible for 4 to 5% of total emissions… a sobering statistic…