The A320 was in cruise, passengers settled, when the air simply stopped behaving. No weather. No warning. Just 575 tonnes of displaced atmosphere finding a 78-tonne fuselage at range the rulebook called safe.
Five passengers were injured. The separation was over seven nautical miles. That detail is the story.
The geometry of the problem starts with how vortex decay was modeled. ICAO's wake turbulence categories — Light, Medium, Heavy, Super — assign separation minima based on how long trailing vortices persist before dissipating to safe intensity. The 'Super' category was created specifically for the A380 when it entered service in 2007. But the decay curves underpinning those minima were built from data on aircraft weighing roughly half the A380's 575-tonne maximum takeoff weight.
The math assumed a smaller aircraft than the one that arrived.
Wing loading and sheer mass determine vortex intensity and persistence. The A380's wingspan generates counter-rotating columns of air that sink, spread laterally, and have been measured persisting significantly longer and at greater intensity than legacy Heavy-category types at equivalent separation distances — not as a theoretical outlier, but in documented characterization studies.
Atmospheric stability amplifies this further. In low-wind, stable cruise conditions, there's no crosswind shear to fracture the vortex structure. The columns simply endure.
The 6nm Super-behind-Super IFR minimum was derived from a statistical envelope the A380's signature sits outside. The Eurowings crew exceeded that minimum. They were operating correctly inside certified parameters. The encounter happened anyway.
EASA and the FAA have reviewed A380 wake spacing periodically since entry into service. No binding revision to en-route separation minima has been mandated. The label 'Super' was applied accurately. The distances attached to that label remain anchored to a pre-A380 world.
The rulebook wasn't wrong. It was simply written before the aircraft existed to prove its limits.