AFAICT they don't exist at all today. They are just renderings. So double clickbait. A more accurate title would be, "Airbus announces plans to develop foldable wing extensions, with non-foldable versions as the first step" or something like that.
The goal is longer, thinner wings than usual. Long and thin wings are far more efficient—think gliders and the U2. But beyond a certain width, those wings become incompatible with existing airports and other facilities for handling commercial aircraft. So the idea is to mount folding extensions that are extended for flight, but likely fold when being hangered or navigating taxiways.
And, importantly, this programme is targetting the next generation of single-aisle aircraft.
It was hard enough to convince a few dozen of the world's largest airports to make the alterations needed to accommodate the A380's wings. Demanding similar changes at the thousands of smaller airports where A320-class planes land would be a non-starter.
> The Wing of Tomorrow programme is centred around creating longer, lighter, and more slender wings to maximise aerodynamic efficiency and reduce fuel burn. The wing extensions will be assembled at Airbus’ Wing Technology Development Centre in the UK and flight tested in Toulouse.
Title: Airbus launches new flight test programme for Wing of Tomorrow
... doesn't look like there's any folding being tested here, just the resulting wing shape to see what the benefits might. Full scale foldable wings would be years off.
You're right, it's a proof of concept: "The extensions, each measuring several metres, will replicate a folding wing in the fully extended position during a flight. They will be fitted with comprehensive testing equipment to capture behaviour in flight and evaluate how the longer wingspan impacts aircraft handling."
So no, they are not foldable today - the headline submitted to HN is total clickbait.
The goal is longer, thinner wings than usual. Long and thin wings are far more efficient—think gliders and the U2. But beyond a certain width, those wings become incompatible with existing airports and other facilities for handling commercial aircraft. So the idea is to mount folding extensions that are extended for flight, but likely fold when being hangered or navigating taxiways.
It was hard enough to convince a few dozen of the world's largest airports to make the alterations needed to accommodate the A380's wings. Demanding similar changes at the thousands of smaller airports where A320-class planes land would be a non-starter.
... doesn't look like there's any folding being tested here, just the resulting wing shape to see what the benefits might. Full scale foldable wings would be years off.
https://www.youtube.com/watch?v=3m5qxZm_JqM