Continuous vertical guidance is one of the most important tools available to a pilot during the final stages of flight. It ensures the crew can maintain a safe height above terrain and obstacles when approaching a runway. In adverse weather, such as low cloud, they can also descend to a lower altitude before needing to make visual contact with the airport. This continuous vertical guidance decreases the chances of a pilot undertaking a go-around or having to divert, saving both fuel and time.

In Australia, vertical guidance has historically been provided by technology like the ILS and in more recent times, accurate Baro-VNAV, RNP AR and GBAS. However, these recent technologies are usually only found in large aircraft, mostly Boeing and Airbus. A Satellite Based Augmentation System (SBAS) allows regional carriers who fly turboprop and smaller aircraft to reap the same benefits as larger aircraft without the need to install ILS infrastructure.