X-Plane 10.30 WACO UPF-7. The WACO UPF-7 was the last of the "F series" aircraft developed by the WACO Aircraft Company during the 1930s. It was was a tandem two-seat trainer powered by a 220 hp Continental W-670-6A engine. Credit goes to Bernard Augras for the use of his pilots. By Philippe Gastebois.