concept

Leading-edge vortex

A low-pressure swirl of air that rolls up just over the leading edge of a flapping or sharply tilted wing — a tiny tornado clinging to the wing's back. That low-pressure region sucks the wing upward, making far more lift than steady, rigid-aerofoil theory can explain. It is the resolution of the "bumblebees can't fly" myth: the old calculation missed this unsteady vortex mechanism. At the low Reynolds numbers of insects the leading-edge vortex is the dominant source of lift — and the kind of aerodynamic trick a flapping membrane wing in Pandora's dense air could exploit too.