Area navigation

Area navigation (RNAV, usually pronounced as /ˈɑːrnæv/) is a method of instrument flight rules (IFR) navigation that allows aircraft to fly along a desired flight path, rather than being restricted to routes defined by ground-based navigation beacons.

The acronym RNAV originally stood for "random navigation," reflecting the initial concept of flexible routing, though the term now refers to a precisely defined and controlled method. This flexibility enables more direct routes, potentially saving flight time and fuel, reducing congestion, and facilitating flights to airports lacking traditional navigation aids. RNAV achieves this by integrating information from various navigation sources, including ground-based beacons (station-referenced navigation signals), self-contained systems like inertial navigation, and satellite navigation (like GPS).

In the United States, RNAV was developed in the 1960s, and the first such routes were published in the 1970s. In January 1983, the Federal Aviation Administration revoked all RNAV routes in the contiguous United States due to findings that aircraft were using inertial navigation systems rather than the ground-based beacons, and so cost–benefit analysis was not in favour of maintaining the RNAV routes system. RNAV was reintroduced after the large-scale introduction of satellite navigation.