GNSS landing in Australia
Sydney Airport has become the first in the southern hemisphere to commission a GBAS landing system.
Sydney Airport’s Ground Based Augmentation System (GBAS) was commissioned into service on 2 July at a VIP ceremony led by the Deputy Prime Minister. The installation had received Australian Civil Aviation Safety Authority (CASA) certification at the end of May.
The Honeywell SLS-4000 ‘SmartPath’ GBAS installation comprises 4 GNSS monitoring antennas with a central computing facility that broadcasts integrity and differential corrections via a VHF data-link to suitably-equipped aircraft's flight management systems (FMS).
GBAS can provide up to 26 simultaneous precision approaches - curved if necessary - within a 42 km (~23 NM) radius from the airport (even for other airports within range) and should reduce maintenance when compared with a traditional instrument landing systems (ILS), which can furnish just one straight approach to one runway.
As Honeywell explains, GBAS approaches can be designed 'to avoid terrain, shorten track miles and reduce noise and emissions while improving traffic throughput'.
Qantas and Airservices had been testing the GBAS since December 2012 - more than 750 approaches have been flown by 737-800s and A380s. That followed on from an earlier prototype which was on trial over 2006-10.
Currently, GBAS has demonstrated accuracy of better than one metre in both horizontal and vertical axes, and is certified to CAT I minima levels (usually requiring to see the runway at a minimum height of 200 ft). But it is planned to improve this to CAT III, with no cloud-base height stipulated.
The SmartPath system is also operational at Newark, Houston, Charleston and Moses Lake in the US and Bremen, Germany.
Details from Australian Aviation below . .