RNAV (GNSS) non-precision approach - flight trials analysis report

The Global Positioning System (GPS) is currently being used for en-route and oceanic phases of flight as a primary means navigation system and as a supplemental navigation aid for more demanding procedures.

The development of GPS has allowed the creation of Area Navigation (RNAV) Global Navigation Satellite System (GNSS) approaches, a type of non-precision approach (NPA) procedure.

The arrival of this new technology, currently realised by GPS, brings with it the need for new techniques, both for the pilot and the air traffic controller.Pilots must make a safe transition from the techniques employed with traditional navigation aids to those required for the new techniques.

This period of transition presents a significant risk in terms of human error and misunderstanding.

The aims of this project were to gain an understanding of pilot experience and interpretation of RNAV (GNSS) procedures within the UK through flight trials at six aerodromes. As well as the objective to understand the complexity of receiver programming and the spatial perception of pilots, other factors such as the interface with air traffic control (ATC), phraseology, traffic, pilot training and issues regarding missed approaches were also considered.