Before a commercial airplane takes off, the pilot has a very clear destination in mind, and a flight plan to get there. The plane leaves at a specific time, and takes off toward a specific destination. The plane is off track, though, at least 90% of the time. Weather conditions, turbulence and other factors cause this.

However, feedback is given to the pilot constantly. The inertial guidance system of the aircraft continually helps the pilot evaluate and revise the plane