GRAHAM WARWICK / WASHINGTON DC
Avionics manufacturers expect certification of first aircraft equipped to use enhanced GPS system in September
Avionics manufacturers expect certification of the first receivers to exploit the near-precision approach capability of the US wide-area augmentation system (WAAS) in September, following commissioning of the GPS satellite-navigation enhancement on 10 July. WAAS was declared operational three years later than originally scheduled.
Commissioning of WAAS allows compatible GPS receivers to be used as the primary means of navigation, as the system improves the accuracy, availability and integrity of the service over most of the continental USA. Initially, WAAS provides lateral and vertical navigation (LNAV/VNAV) for near-precision approaches down to a 350ft (105m) decision height. The US Federal Aviation Administration has designed 500 LNAV/VNAV approaches for around 200 airports, and plans to add 300 a year.
The approaches require a certificated receiver, and UPS Aviation Technologies expects to be first to gain LNAV/VNAV approval for its general aviation GPS/WAAS navigator in September. Also in September, the FAA plans to publish the first so-called lateral precision with vertical guidance (LPV) approaches, which provide guidance down to a 250ft decision height. LPV will be the most precise approach capability offered by WAAS until GPS is upgraded early next decade with a second civil frequency. Only at that time will WAAS be able to provide the originally planned Category I precision approach capability down to 200ft.
Meanwhile, the FAA plans to improve the availability and geographic coverage of WAAS by adding ground reference stations and geostationary broadcast satellites.
UPS Aviation Technologies will provide an LNAV/VNAV-approved GPS/WAAS receiver for Chelton Flight Systems' FlightLogic electronic flight-instrumentation system, which will be installed in up to 200 general aviation aircraft under Phase 2 of the FAA's Capstone programme. The UPS receiver will replace the original Free Flight Systems' unit, says Chelton. Garmin is upgrading its popular GNS 430/530-series of general aviation GPS navigators with WAAS capability.
Source: Flight International
