An air vehicle includes a bag skirt extendable along a portion of a hull of the air vehicle. The bag skirt is inflatable to provide an air cushion during touchdown and deflatable during flight of the air vehicle. The air vehicle also includes a cover roller adjacent the bag skirt, and a cover portion coupled to the cover roller. The cover roller is operable between exposed position and unexposed positions to expose and hide the bag skirt with the cover portion. The cover roller includes an extensible shaft and a pad securely wrapped around the extensible shaft. The extensible shaft is capable of being rotated along a shaft axis. One end of the extensible shaft is pivotally coupled to the hull by an anchor. A circumference of the cover roller is configured as a function of a distance between the exposed and the unexposed positions.