One of Stratasys' clients is UAV Solutions of Maryland, who, obviously, manufacture UAVs. But they now do this with 3D printing.
Their journey is similar to many manufacturers who encounter 3D printing: at first it's a novelty, then it becomes something used for unusual situations and finally:
3D printing has now “crept” into every aspect of their manufacturing process.
The firm discovered that Stratasys' ULTEM material - a very high temperature resistant substance - also had a very good strength to weight ratio. In other words, it's good for airplanes. They exploited this feature by building a UAV that was "99%" manufactured on one of their four Fortus 400mc 3D printers. It flies, as you can see in the video.