erreur grossière de navigation

CONT: Gross navigational error (GNE) - Pilots are expected to fly their aircraft along the centerline of their assigned route and to stay within the accuracy limits of their installed navigation systems. (For example, the accuracy tolerance limits for Loran C equipment used in instrument flight rules (IFR) oceanic navigation is 5.8 NM). If an aircraft becomes off course, it is usually for one of the following reasons; a ""loop"" (or communications) error between the pilot and the controller, a pilot intentionally entering a waypoint which is not along the assigned route of flight (for example, a pilot deviation due to weather without prior ATC approval or without declaring an emergency), an unintentionally entered waypoint not along the assigned route, and a navigational equipment error or failure. Navigational errors that are greater than 20 NM are investigated by the various countries that provide ATC service.