Passive aerodynamic robustness reduces disturbance amplification in flight

Abstract

Although limiting flight responses to flow disturbances is typically considered an active-control problem, birds often sustain fixed-wing gliding in disturbed air, raising the question of whether the wing itself can passively limit these responses. Here, we show that avian wings exhibit passive aerodynamic robustness to disturbances. Compared with a planform-matched rigid airfoil wing, the avian wing exhibits lower lift-response gain, smoother stall transition, reduced force fluctuations, and a broader operating angle-of-attack range across turbulence intensities. These wing-level properties translate into an expanded passive stability envelope in rigid-flyer dynamics. Flow diagnostics associate this robustness with delayed separation and altered distributions of turbulent kinetic energy. This robustness comes at the cost of reduced aerodynamic efficiency, revealing an efficiency-robustness trade-off in disturbed flows. We identify aerodynamic sensitivity and control demand as key metrics for bird-scale flight in turbulence and suggest passive aerodynamic robustness as a design principle for resilient flying systems.

The authors' abstract, as published at the source. Cell Reports Physical Science, 2026 · DOI ↗