What is Performance Based Navigation (PBN)?

Broadly, PBN encompasses a shift from current ground-based navigation aids emitting signals to aircraft receivers, to ‘in-aircraft’ systems that receive satellite signals such as from the United States’ Global Positioning System (GPS) that meet specific accuracy and integrity requirements to advise the aircraft’s position to the crew. PBN therefore:

  • reduces the need to retain and maintain ground-based routes and procedures
  • allows for more efficient use of New Zealand’s airspace, reducing fuel usage and emissions

In early 2008, the Ministry and Civil Aviation Authority (CAA) had representations from the aviation industry for a coordinated approach to assist the fuller implementation of PBN in New Zealand, including an appropriate regulatory framework to allow the use of advanced navigation technology by aircraft operators.

Accordingly, the Ministry and CAA held a joint workshop in June 2008 on the future development and introduction of PBN in the New Zealand air traffic system. Participants included airlines operating in and to/from New Zealand; the Airways Corporation of New Zealand; the Aircraft Owners and Pilots Association; the Aviation Industry Association; the Board of Airline Representatives; the New Zealand Defence Force; the New Zealand Airports Association; and the Royal New Zealand Aero Club.

In 2009, the CAA prepared a PBN Implementation Plan to conform with a 2007 resolution of the Assembly of the International Civil Aviation Organization (ICAO) that called on member States to complete an implementation plan for PBN by the end of 2009.

PBN uses Global Navigation Satellite Systems (GNSS) – satellite systems that provide navigation information to aircraft systems to allow navigation without ground based systems. For example, GPS is one, the European Union, Russia, and China also have such systems. The principal elements of PBN are:

  • Area Navigation (RNAV) – is a method of navigation that allows an aircraft to choose any course within a network of ground-based navigation beacons, or GNSS aids, or a combination, rather than navigating directly to and from the beacons.
  • Required Navigation Performance (RNP) – is a type of PBN that allows an aircraft to fly a specific path between two 3-dimensionally defined points in space. RNAV and RNP systems are fundamentally similar.

The key difference between them is that RNP requires on-board performance monitoring and alerting. For example, typical RNP approaches to an airport are accurate to 0.3 nautical miles either side of the desired track, and allow aircraft to follow precise 3-dimensional curved flight paths through congested airspace, and through difficult terrain (such as around Queenstown).

Some elements of a PBN system are already in use in New Zealand to meet industry needs, for example, the Required Navigation Performance (RNP) approaches to Queenstown and Rotorua Airports, and RNAV Global Navigation Satellite Systems (GNSS) routes and non-precision approaches to many aerodromes.

The government agreed in August 2011 to the development of a National Airspace Policy and a National Airspace and Air Navigation Plan. The Policy was issued on 24 April 2012. The CAA is leading the development of the Plan, and PBN will be an important component of this work.

For further information on PBN in New Zealand, visit the New Southern Sky website(external link).