Rules governing flight during periods of generally good visibility and limited cloud cover (i.e., a pilot’s ability to fly and navigate by looking out the windows of the airplane), predominantly employed by piston-powered general aviation. Aircraft flying under the VFR system are not required to be in contact with air traffic controllers and are responsible for their own separation from other aircraft. The visual flight rules (VFR) system is utilized almost exclusively by recreational pilots or low-flying piston-engine airplanes.