If you add 5 points to the 8-character flight, the whole route of the simulated flight is divided into () segments+D+A+8+B.10+C.
Because the guidance of the plane is segmented, that is, whenever the plane flies to a point, it sends a signal through the signal tower to tell where the plane is now and guide the direction of the plane.
The route is segmented, because the route is long and small, which is convenient for the management department to manage.