Airbus engineers have developed AlbatrossOne, a scale-model airplane with the first in-flight, flapping wing-tips that could revolutionize aircraft wing design. The flapping wings are constructed from carbon fiber and fiberglass-reinforced polymers, as well as components from additive-layer manufacturing.
The ‘semi-aeroelastic hinge’ concept of the flapping wing-tip on AlbatrossOne serves to reduce drag and overall wing weight while combating the effects of turbulence and wind gusts. Engineers at Airbus derived the concept from nature. Airbus engineer Tom Wilson explained, “While hinged wing-tips are not new – military jets employ them to allow greater storage capacity on aircraft carriers – the Airbus demonstrator is the first aircraft to trial in-flight, freely-flapping wing-tips to relieve the effects of wind gusts and turbulence. We drew inspiration from nature – the albatross marine bird locks its wings at the shoulder for long-distance soaring but unlocks them when wind-gusts occur, or maneuvering is required.”
Mr. Wilson added, “The AlbatrossOne model will explore the benefits of unlockable, freely-flapping wing-tips – accounting for an up to a third of the length of the wing – to react autonomously during in-flight turbulence and lessen the load on the wing at its base, so reducing the need for heavily reinforced wing boxes.”
Jean-Brice Dumont, Airbus’ Executive Vice-President of Engineering, pointed out more benefits of the innovative design, saying, “When there is a wind gust or turbulence, the wing of a conventional aircraft transmits huge loads to the fuselage, so the base of the wing must be heavily strengthened, adding weight to the aircraft. Allowing the wing-tips to react and flex to gusts reduces the loads and allows us to make lighter and longer wings – the longer the wing, the less drag it creates up to an optimum, so there are potentially more fuel efficiencies to exploit.” The revolutionary flapping wing-tips are made of carbon fiber and fiberglass, as well as other additively manufactured components.
The remote-controlled AlbatrossOne has already taken its first flights to prove the flapping wing-tip concept, and the team will continue testing before the demonstrator, based on the manufacturer’s A321 plane, is scaled-up. Initial testing examined stability with the wing-tips locked and completely unlocked. Airbus engineer James Kirk added, “The next step is to conduct further tests to combine the two modes, allowing the wing-tips to unlock during flight and to examine the transition.”