Airbus Tests Bird-Like Flapping Wings For Future Aircraft

The Airbus technology demonstrator, AlbatrossONE, which uses ‘flapping wingtips’ for increased efficiency, has reached a new milestone. The research team has achieved proof of concept through a ‘gate to gate’ demonstration, giving the idea the green light to be matured into a full-scale technology.

AlbatrossONE flapping wing Airbus
The Airbus flapping wing concept has reached a new milestone. Photo: Airbus

AlbatrossONE reaches a significant milestone

It was almost a year and a half ago when Airbus unveiled its ‘flapping wing’ concept. Designed to mimic the aerodynamic qualities of birds, the AlbatrossONE wing design would have semi-elastic wingtips, allowing them to flex in flight. In 2019, Airbus demonstrated the concept on a miniaturized version of one of its aircraft.

Since then, the development team has been somewhat quiet, until now, that is. This week, Airbus revealed that the AlbatrossONE project had reached a new milestone. The planemaker states that it has achieved a ‘gate to gate’ demonstration using wingtips that are 75% longer than those tested on the previous model.

Airbus used the remote control demonstrator aircraft again, but this time looked to test the concept of freely flapping wingtips of a greater size. The successful conclusion of this phase of the project marks the achievement of ‘proof of concept’ by Airbus on a small scale, at least. While there’s still a way to go before it becomes a reality, it’s a significant milestone on the road to mature the technology.

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What’s so cool about flapping wings?

Aircraft design has long been inspired by nature, from the basic aspect ratio of a flying machine to efficiency improving winglets. This strategy, known as biomimicry, has led to numerous exciting projects in aerospace innovation, including Airbus’ recent Fello’fly concept and development of shark skin-like fuselage coverings for aircraft.

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Nature has always inspired aircraft design. Photo: Airbus

Semi-elastic or ‘flapping’ wings replicate the wingtips of the albatross. The bird has the ability to unlock its shoulder to navigate wind speeds, letting it travel long distances and cut through turbulence. AlbatrossONE Chief Engineer James Kirk explained how this would translate to passenger jets, saying,

“Semi-aeroelastic hinged wing-tips enable an aircraft to “surf” through wind gusts without transferring the bending loads (i.e. external load that produces bending stresses within a body) to the main wing.

T”his means we require less material, such as carbon-fibre-reinforced polymers, to make the wing strong enough to withstand the gust loads, thus reducing the weight of the aircraft. Also, the length of the wing-tip can be extended without adding weight to the wing because the extra loads from the longer wing-tip are not passed to the main wing.”

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The wing modification could reduce turbulence and improve efficiency. Photo: Airbus

Airbus believes that this modification has the potential to reduce significant amounts of fuel burn and CO2 emissions. It would also allow aircraft to have far greater wingspans, as Airbus Semi-Aeroelastic Hinge Project Leader Tom Wilson explains,

“Lift-induced drag accounts for about 40% of a large aircraft’s drag. But this figure falls as the wingspan increases. The semi-aeroelastic hinged wingtips’ span could potentially be increased beyond 50 meters without increasing wing weight.”

What testing was completed this time?

The team completed a second flight test campaign this summer. This involved a ‘gate to gate’ demonstration, including moving the wingtips from vertical to horizontal position and back again. The team also enabled the wingtips to flap just prior to takeoff to improve roll control and to navigate high load during flight.

Part of the testing involved ‘tether testing,’ which saw the model aircraft suspended above the ground. This allowed engineers to test its handling capabilities.

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Tether testing saw the plane suspended from the roof. Photo: Airbus

While suspended, the aircraft was swung from side to side like a pendulum. This tested the mass properties of the AlbatrossONE demonstrator.

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Swing testing assessed its mass properties. Photo: Airbus

In a rather unusual looking test, the wing of the demonstrator was tested while mounted to the side of a van. This allowed the engineers to test out the wingtip release and recovery mechanism.

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The wings were wind-tunnel tested using a van. Photo: Airbus

So will we see flapping wings on any commercial aircraft soon? Probably not. While this proof of concept lays the groundwork to mature the technology at a larger scale, there is still a lot of engineering work to be done before the product is proven as a viable solution.

What do you think about the flapping wingtip idea? Let us know in the comments.