A cavity in an airframe from which an airfoil is deployed is automatically closed to reduce aerodynamic drag by a fairing element hinged to the force and aft cavity edges and resiliently deformable from an unbent aerodynamic position outside the cavity to a bent position within the cavity. The non-deployed airfoil overlies the bent fairing element and retains the fairing in a bent position against the resilient force tending to restore it to the unbent position, until airfoil deployment.