Airbus flies ‘flapping wings’ demo based on Albatross seabird

+VIDEO Airbus has flown its AlbatrossONE demonstrator with wing-tips that are 75% longer than before to prove that freely flapping wing-tips can alleviate wing loads and avoid tip stall for improved aircraft performance.

Airbus says the albatross seabird has a lot to teach aeronautical engineers about improving aircraft performance. The Airbus demonstrator is small-scale, remote-controlled aircraft, which features ‘semi-aeroelastic’ hinged wing-tips.

Quick questions with Tom Wilson, Semi-Aeroelastic Hinge Project Leader, & James Kirk, AlbatrossONE Chief Engineer

Q: The AlbatrossONE project is inspired by the albatross seabird. How did this unique seabird inspire Airbus engineers?

Tom: “The albatross’ wing-tips are actually somewhat analogous to semi-aeroelastic hinged wing-tips. The albatross can ‘lock’ its wings at the shoulder to travel long distances, but when faced with wind gusts, it can ‘unlock’ its shoulder to better navigate wind speeds. Semi-aeroelastic hinged wing-tips behave in the exact same way.”

James: “Also, as a neat coincidence, the semi-aeroelastic hinged wing-tips’ long span could have an aspect ratio (ie the wing span to its width or chord) of around 18 (versus 9 or 10 for today’s aircraft). This is exactly the same ratio as that of the largest albatrosses. Wing span and aspect ratio are important for reducing aerodynamic drag.”

Airbus Albatross ONE

Q. What makes ‘semi-aeroelastic hinged wing-tips’ so innovative?

James: “Semi-aeroelastic hinged wing-tips enable an aircraft to ‘surf’ through wind gusts without transferring the bending loads to the main wing. This 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.”

Q. How does this impact aircraft performance?

Tom: “Semi-aeroelastic hinged wing-tips are remarkable because they would enable a step change in aircraft performance: a major increase in wing span with minimal impact on wing weight would reduce drag, leading to significant reductions in fuel burn and CO2 emissions.

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

Q. Will the semi-aeroelastic hinged wing-tip concept be applied to future aircraft? And if so, when?

Tom: “Now that proof-of-concept has been achieved at small scale, we’ll increase our efforts to mature the technology at a larger scale.”

James: “There’s still a lot of engineering work required before we can prove it’s a viable product. But the project team is motivated to achieve this goal and to inspire other engineers to think ambitiously about future aircraft!”

Airbus AlbatrossONE