Windrunner, the next giant of the air

The destruction of the Antonov Mriya, which means "The Dream" in Ukrainian, by Russian attacks at the beginning of the war between those two countries, marked the history of what was once the largest and most powerful civilian cargo aircraft in the world. Materially unrecoverable, although there are rumors of making a second aircraft from the wreckage and the spare parts available to keep it operational, the AN 125—its technical name—will go down in history as an aeronautical giant in a few years, at least five, if the new giant of the air spreads its wings.

It is called Windrunner in plans and studies, a name that leads us to questions beyond the purely aeronautical ones or the ever-present advertisements, models and drawings of probable supersonic passenger aircraft to replace the services of the archived Concorde.

Indeed, the Windrunner is not a flying whim, but a tool born from the changing energy conditions of the world and the enormous power requirements required by artificial intelligence (AI) and cryptocurrency processors, both to "think" and to cool their brains.

The motivations for this emerging project are a response to the world's upcoming demands for sustainable electricity, whose advances cannot be met with current generation infrastructure. Data from 2022 indicate that AI and cryptocurrency calculations consumed 460 terawatt hours—a measure we mere mortals don't understand, but which is better explained by noting that it was 2 percent of global debt. By 2030, demand will double, and the overwhelming water consumption required to cool processors is also a limiting input for its expansion. Every time a person uses ChatGPT, their request goes to those data centers, causing workloads. The traffic is impressive: more than 400 million weekly active users and 3.905 billion visits to its website in February of this year alone.

Why do these figures converge with a giant aircraft ? Why make an aircraft that would have a cargo volume 12.6 times greater than that of a Boeing 747 Jumbo or whose belly would be 6.6 times wider than that of the Antonov 124, the 125's smaller cargo aircraft? Today, there are more than 200 original or converted Jumbos flying with cargo, an alternative that the Airbus A380 couldn't effectively offer for converting from passenger to bulk transport due to its cockpit being in the center of the fuselage, unlike the 747's, which is on a second deck and allows the nose to open for the loading of enormous parts. That's the reason why many Jumbos have been converted for this task, for which the A380's side doors aren't as versatile for certain operations. But the aircraft that now perform these services are limited for some future operations that will be inevitable.

The answer lies beyond the world of mega-aircraft, as it lies in the limitations of wind-generated electricity from reactive wind turbines. Although we frequently see them in pictures, and rarely in physical form, only in certain parts of La Guajira, Colombia, you have to stand in front of one of these towers to appreciate their dimensions. The largest have blades measuring eighty meters, which is about a city block long, and require structures between 100 and 150 meters tall, like a 30-story building. However, they also require minimal physical land space to build, unlike hydroelectric, thermal, or nuclear power plants.

Turbines, as these wind farms are called, have limitations because their rotation speed is strictly controlled, as they can run wild and cause extensive damage if the blades become detached or vibrate. They operate in winds between 3.5 and 11.5 meters per second, but if the currents are stronger, the blades change profile and the mechanisms that turn the generators on the towers slow down . At the other end of the spectrum, they also stop if the currents are weaker, as is the case in most land areas of the globe, which is why they are currently in relatively limited use.

If these blades were longer, increasing from 80 to 100 meters or more, the windmill's performance would increase significantly, and electricity production would increase, as they could be installed in locations where the wind force is not as strong, and many wind farms could be created around the world. Furthermore, building these new towers on land is much more economical and functional than installing them on marine or offshore platforms, as the industrial world beyond the coasts is known. Also, being much longer, the blades have a much greater axis of force or "torque" to drive more powerful generators whose rotational resistance is proportional to their greater current output. They also have a larger area exposed to the wind force, so they rotate with less load.

There the Windrunner lands. It turns out that blades longer than 80 meters, the maximum available today, are not feasible to transport on current or future road infrastructure. Their length would cause them to get caught in many curves in roads and tunnels, and such dimensions cannot pass under bridges.

Therefore, the aircraft planned to transport them will be enormously long , proportional to the need to carry such large items. The fuselage will measure 108 meters between its ends, which open for operations, rise 24 meters from the platform (7 floors), and have a 10 × 10 m opening, with wings that total 80 meters of span, for a volume of 7,702 cubic meters. In comparison, a 747 "cargo" aircraft stretches 70.7 meters, has a peak of 19.2 meters, uses 64.4 meters of aluminum wings, and offers 610 cubic meters of internal volume. The Antonov 124 also falls short, with its dimensions of 68.8, 20.7, and 73.3 meters for its length, height, and wing size, respectively, and volume of 1,160 cubic meters.

In any case, the Windrunner must adapt to the operation of airways and patterns in current airspace and operate within the speed range of commercial aircraft. They advertise a normal speed of 0.86 Mach, a ceiling of 41,000 feet, and a range of 1,200 nautical miles, enough to travel from Bogotá to Miami nonstop, which represents many stopovers on long routes. Since the airports are specific, it has no limitations in this regard, and only uses aprons for intermediate stops.

Clearly, the Windrunner's biggest difference is its length, reflecting its goal of carrying the blades of the future, whose proportions justify the enormous space that can accommodate three of the current 80-meter blades, two 95-meter blades, or a future one of up to 110 meters. The blades' length requires a larger proportional structure, which is why they not only grow longer between the tips but are also much thicker structurally, although they would be made with state-of-the-art ultralight materials. This means that the next aircraft's capacity will be only 72.5 tons, compared to the Jumbo, which takes off with up to 124 tons in its guts, and the Antonov, with 120. Size trumps weight , and in this case, it obviates the need for four engines, since currently available engines have the necessary thrust and even more, so it wouldn't need as much runway.

This has a second benefit, which is probably its greatest advantage. As light as its payload, the Windrunner can land on unpaved runways of just 1,800 meters, which is half the length of its competitors. This is imperative for its functionality because it must deliver the elements practically to their assembly site, since once on the ground, they would require only minimal movement to accommodate them. These runways can be temporarily adapted for each service, and their characteristics make them theoretically "transportable" to the most convenient and strategic locations within the same generating sites.

Behind the project are not major commercial aircraft manufacturers like Boeing and Airbus, nor Lockheed , a military company. It's a private group—Radia—with large investment funds behind it, anchored in the United States, specifically in Boulder, Colorado. It has been involved not only in aircraft but also in mega-generation wind power for a decade, but only unveiled its concrete proposals last March during the recent Paris Airshow. Its manager, Mark Lundstrom, an American, gives an excellent definition of his premises: "Engineers and product development people around the world haven't tried to invent bigger things because they know they're not transportable." For this reason, Radia's work goes hand in hand with the Gigawind project, which is quickly taking off.

During the Paris event, several partners were announced. Aciturri, a Spanish company specializing in lightweight aerostructures, will be responsible for the design and construction of the aircraft's empennage (the tail and its wings). Akaer Engenharia, a Brazilian company, will be responsible for pressurization and systems integration. Astronautics Corporation, a US company, will work on all the aircraft's avionics. Element Materials Technology, a British company, is responsible for the fuel systems. Ingenium Technologies, another US company, will be responsible for the entire high-lift design for the aircraft. Other high-tech and capacity firms such as the Italian Leonardo, Magroup, which works on landing gear, Magnaghi Aerospace, Aernnova and AFuzion have already been involved in the subject for some time, and other research centers will surely join in to develop this project, which, more than an adventure, is becoming the solution to a pressing need for the more universal development of energy generation with clean and efficient sources, such as the free ones offered by the wind or the sun's rays, the latter of which are less efficient.

A paradox arises here. The wind depends on the sun, which heats the Earth's uneven surface, causing the air to acquire different temperatures, resulting in different atmospheric pressures, the differential of which produces currents.

To achieve these new amounts of electricity, wind power is more effective than solar because it operates 24 hours a day, although the wind is also not constant and wind turbines cannot be installed in urban areas. These are noisy, more expensive, and are usually located in remote locations requiring long transmission lines, but they are much more productive, and will become even more so if airplanes arrive with the new extra-large blades that would make them almost indispensable.

For now , electric windmills are limited, and their stature will depend on the landing of the Windrunner or similar devices that fly over terrestrial limitations. These advances will also depend on the new functions of a world that increasingly thinks and operates through machines, which also require food to function, and whose scarcity is already predictable.

José Clopatofsky - Director of MOTOR

*With information from Radia, Primeweb, Aerosociety.com, Aviation2z.com, Antonov and Boeing.