Plain English Meaning

Air that is no longer flowing smoothly across the wing and is instead breaking up into messy, unsteady swirls that the wing can't work with properly.

Full Definition

Disorganized, unsteady airflow over a wing or control surface in which the air separates from the surface in irregular, unpredictable patterns rather than flowing smoothly or in a structured turbulent layer. It typically occurs at high angles of attack and degrades lift, increases drag, and reduces control effectiveness.

Context Anchor

Seen in discussions of vortex generators, which create small, planned swirls of air to help manage airflow over the wing at slower speeds.

Derivation

From Latin turbulentus, meaning 'restless' or 'disturbed.' 'Uncontrolled' here means the is not or managed by the wing's shape or by any flow- device — the air is doing whatever it wants.