This new flying Batmobile was first introduced in the Batman Beyond episode, "Black Out", when Terry McGinnis had to pursue the shape shifting criminal Inque, and has used it ever since. It can be assumed that Bruce Wayne must have built it some time after he retired as Batman, as when he retired, that sort of technology was probably not present yet to make that sort of Flying car, and its design is more similar to other flying cars of the Beyond era.