Ian Sheppard/LONDON
Complex precision approaches to some of the world's most inaccessible airfields could soon be possible after the Norwegian Civil Aviation Administration (NCAA) successfully completed evaluation trials of a new satellite navigation landing system.
The trials were conducted at the northern Norwegian airport of Bod¿, where Raytheon has installed a ground reference station to supply differential global positioning system (GPS) signal errors to aircraft. Bod¿ already has an instrument landing system which allows the satellite approach to be overlaid for comparison, although the new system's main benefit is an economic one, with the cost per airfield around one-tenth that of ILS, which was previously planned for installation at many of Norway's smaller strips.
The airborne equipment consists of a Universal Avionics UNS-1B flight management system (FMS), navigation computer, GPS sensor and datalink receiver installed on the NCAA's Bombardier de Havilland Dash-8 test aircraft. Universal's aim is to integrate these systems into a single unit, the GLS-1250, which is being developed concurrently with the Norwegian test programme.
Norwegian airline Wideröe, which has a route network covering many of the fjords of northern Norway, has upgraded its Dash 8 fleet with the same Universal Avionics equipment as the NCAA aircraft and is playing an active part in the programme.
Raytheon's ground reference station is being brought into line with the RTCA DO-217 standard, which specifies minimum standards for DGPS instrument approach systems under so-called special category 1 (SCAT-1).
The primary aims of the programme's second phase will be to specify Norway's certification needs, identify weaknesses in DO-217 and to increase navigation accuracy by an order of magnitude over SCAT-1, using the so-called "truth reference system".
SCAT-1 is also the benchmark for the newly certificated Honeywell/Pelorus SLS-2000 system which is being used to develop procedures for helicopters with Universal's UNS-1 FMS (Flight Inter- national, 25 February-3 March).
The latest version of Universal Avionics' FMS software, SCN 603, has received US Federal Aviation Administration approval. SCN 603 allows Universal's UNS-1 range to support sole means satellite navigation and approach guidance using the US global positioning system and its Russian equivalent GLONASS.
Source: Flight International
