RNAV
Area Navigation is a navigation method that enables that aircraft operation on any desired flight path within station referenced navigation aids or within capability limits self-contained aids or a combination of both.
The concept of area navigation is operating from navigation aid to navigation aid along routes that were more or less permanently established, could advantageously be replaced, or complemented by one whereby aircraft could plan and operate along the most direct route between their point of departure and their destination.
RNAV is achieved through a combined use of aircraft navigation accuracy, route separation, and air traffic route intervention. An RNAV system is used in the horizontal and vertical separation minima’s of airplane.