X-Plane 9+ FN-1A. This is an idea for a light attack aircraft based on a balsa glider design that flew very well. Scaling up the design and figuring how to fine tune the airframe for trans-sonic flight was a challenge. This model is not supersonic, but it is stable (trimable) and very manoeuvrable. The stall is 130 mph so approach should be no slower than 135 mph. Top speed is mach 1.00. By Ron Norvelle.