Aircraft operating anywhere in Europe now have access to satellite-guided precision approaches with the formal launch of the EGNOS safety-of-life service.
EGNOS is the European counterpart to the wide area augmentation system (WAAS) already available in the USA.
While signals from the GPS navigation satellite constellation, or Europe's similar Galileo constellation, whose first satellites will be launched this year, give position data accurate to at least 10m (33ft), EGNOS takes that accuracy of vertical and horizontal position down to less than 1m.
Fixed- or rotary-wing aircraft equipped with a suitable receiver and cockpit display thus can dramatically improve the safety of their landing approaches.
European Commission vice-president for industry and entrepreneurship Antonio Tajani stresses that the free-to-use signals are a public service, and private companies are encouraged to develop receivers capable of exploiting them.
While not a substitute for traditional, ground-based air traffic control and guidance systems, EGNOS or WAAS are particularly valuable in poor weather at airfields too small to invest in expensive, ground-based instrument landing systems.
Improving positional accuracy will also allow for decreased separation between aircraft in poor weather, more direct routeing and the start of descent closer to the runway, possibly reducing delays, CO2 emissions and noise near airports.
EGNOS works through a network of 40 ground stations that gather position data from the GPS satellite constellation and, soon, Galileo, and beam that up to transponders aboard three satellites in geostationary orbits over Europe. The amalgamation of data from many stations and navigation satellites results in a more precise positional signal that is beamed back down to receivers aboard aircraft or other vehicles.
The key development that pushed EGNOS from its trial to operational phases was the certification of safety-of-life service operator ESSP, in Toulouse.
Source: Flight International
