Evergreen prepares for GPS augmentation trials

Evergreen Airlines has confirmed that it is to begin equipping the first of six Boeing 747 freighters with a Universal Avionics flight management system to boost GPS accuracy using a variety of global satellite-based augmentation systems (SBAS).
Flightglobal´s John Croft reports how, under the US Federal Aviation Administration (FAA) programme, Evergreen will fly the avionics on its global routes for up to two years, taking data on how well the aircraft maintains desired courses or approaches using four different augmentation systems.
Evergreen is taking data on the same routes now with existing, non-SBAS FMS units as a baseline.
In the US, the wide-area augmentation system (WAAS) generates accuracy boosting correction signals that when combined with basic GPS signals in on board receivers increases position accuracy from 10m to less than 1m using a constellation of three geostationary satellites and a network of ground stations.
Evergreen plans to retrofit the existing Universal UNS-1F FMS units in the 747Fs with UNS-1Fw (WAAS-equipped) units through 2012, with the first aircraft completed by the end of January, said Scott Campbell (pictured), director of airline and military marketing for Universal. Additional 747Fs will be retrofitted every one to two months thereafter through 2012, says Campbell.