Patent attributes
An aerodynamic underbody fairing or “skirt” that is attached to the rear wheels or “bogeys” of a truck cargo body which typically can be slidably adjusted forward and aft along the cargo body. The various embodiments allow for a skirt that attaches to the bogeys of a truck cargo body and extends rearward to the rear plane of the trailer, and is of a retractable nature to allow for slidable adjustment of bogeys forward and aft along the cargo body for the purpose of continuing streamlined flow along the side of a truck cargo body already equipped with a side skirt forward of the bogeys. In the various embodiments of the invention, the retractable nature of the invention allows for a continuous skirt surface in-plane with the side of the truck cargo body extending from the bogeys to the rear plane of the truck cargo body, regardless of bogey position.