Performance Based Navigation (PBN)

Traffic plots made at Chicago Rockford International without and with a PBN design. Source: Miller, S. 2009. Contribution of Flight Systems to Performance-Based Navigation. Aero Magazine. 2:21-28


The FAA defines Performance Based Design (PBN) as "a framework for defining navigation performance requirements that can be applied to an air traffic route, instrument procedure, or defined airspace". The goal of PBN is to consolidate the different types of RNAV and RNP in such a way as to design and implement more accurate and efficient automated flight paths. PBN is the next step forward in the evolution of aeronautical navigation.

Conventional navigation relied on radio beacons, such as VOR, DME and NDB. After RNAV was introduced, airplanes would fly to waypoints that weren't tied to ground-based navaids. RNP, which is based on RNAV, optimized the airspace even further by replacing strict point-to-point routes with more gradual turns.

According to Boeing, which has included RNP capability in every airplane, PBN will result in a significant reduction in track miles through reduced vectoring, saving time, fuel, and emissions. With PBN, the airplane’s own capability determines whether it can safely achieve the specified performance and qualify for the operation. One example of this is the SAAAR approach (i.e., Special Aircraft and Aircrew Authorization Required). CAT II/III approaches are essentially SAAAR, but they assume you're already lined up on final. An example of a PBN-type SAAAR approach is the Palm Springs RNAV RNP Z Rwy 13R apporach (below), which has a finely tuned narrow obstacle clearance path, optimized turn radii, a seamless vertical path.