There are paths in the sky called air routes. Planes fly along air routes.

Because planes fly at very high speeds in the air, if they passed too closed to one another, this could be extremely dangerous. This is why the direction and height in which airplanes should fly has been set in order to keep flying safe. The airplane follows the orders of the airport and the air traffic controller in the control center.
In the control center, information taken from radar equipment which is set up in various locations is input into a computer. Information such as the location of the plane in flight can be received quickly. Based on the information the air traffic controller gives the plane instructions.

Airplanes leaving the airport take instructions from the airport’s air traffic controller for a certain time after take-off.
After that, the air traffic controller in the control center takes over from the airport’s air traffic controller. As the airplane gets near its destination airport, the airport’s air traffic controller takes over from the control center’s air traffic controller.
The air space over Japan and the surrounding oceans have been divided into four areas. In each area there is a control center to ensure safe flying.