EGNOS: making landing approaches more precise and efficient

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13 February 2010

EGNOS provides airports and airlines with the precision and reliability needed for guiding and landing aircraft, said speakers at a Galileo Users Forum (GUF) workshop, held on 3 December 2009 in Brussels.

Thomas Feuerle, a flight engineer and research pilot at the Institute of Flight Guidance at the Technische Universität Braunschweig in Germany, told the workshop that satellite navigation is the technology of choice for precision landing approaches.

The Institute of Flight Guidance has been testing the use of augmented global navigation satellite systems (GNSS) for landing aircraft at its aerodrome in Braunschweig. In particular, the Institute focuses on testing satellite-based augmentation systems (SBAS), such as Europe’s EGNOS, and ground-based augmentation systems (GBAS).

Localiser performance with vertical guidance (LPV) approach procedures using EGNOS bring the pilot’s decision height down to 200 feet (about 60 metres), said Feuerle. The height refers to the point during the approach at which the pilot must make a decision about whether to continue the landing or to abort it.

A lower decision height makes it more likely the pilot can see the visual references at an airport to make the landing.

GBAS, which uses local ground infrastructure to calculate and transmit to incoming aircraft correction data to the GNSS navigation information, has the potential to bring the decision height much lower.

Feuerle stresses that both SBAS and GBAS contribute to making landing approaches safer and more efficient, as indicated by tests run at the Institute.

“In our opinion EGNOS and GBAS are complementary systems for aircraft landing operations,” he said. “Many airports and aircraft can benefit.“

Developing EGNOS, launching Galileo satellites

Stefano Scarda, a policy officer with the European Commission’s Directorate-General for Energy and Transport, provided an update on the EU’s statellite navigation programmes.

EGNOS’ Open Service was launched on 1 October 2009 and is available to anyone with a GPS receiver compatible with satellite-based augmentation systems. The EGNOS Data Access System (EDAS), a commercial service, is currently undergoing beta testing by a number of companies and organisations.

The Safety-of-Life Service, intended for safety critical applications, is on course to be launched in 2010 after certification for use by the aviation sector. The process requires the certification of the designated service provider, ESSP, under ‘Single European Sky’ regulations. The application is being overseen by France’s national supervisory authority for aviation.

Hans de With, the Aviation Market Development officer with the European GNSS Supervisory Authority (GSA), said a cost-benefit study of the aviation sector has indicated that the combined economic benefits of EGNOS and Galileo will add up to €2.4 billion between 2010 and 2030.

The market benefits derive from the reductions in flight delays and diversions due to the lower decision height. Airline operational costs will also be lower.

“On top of market building effects, people will benefit from EGNOS and Galileo,” he said.

The public benefits include the creation of new jobs through the development of new applications using EGNOS and Galileo, improved safety in air transport, and the reduction in CO2 emissions due to more efficient landing procedures.

As an agency of the European Commission, the GSA is working to promote the adoption of EGNOS by the market. About €7.5m is available through the EU’s Seventh Framework Programme (FP7) to co-finance about 100 LPV procedures throughout Europe.

The aim is to create clusters of paired airports with EGNOS LPV procedures in place as a means of encouraging regional airlines to adopt the technology. About 15 LPV procedures are planned for 2010.

Flight and ground handling demonstrations for business aviation, helicopters, private planes and regional airlines have been conducted through Framework Programme financing.

Czech Republic develops EGNOS approaches

Ivan Hubert, Director of Corporate Development and International Coordination with Air Navigation Services of the Czech Republic, said the country is investigating all the possibilities of using satellite navigation for civil air traffic management.

Through the Mielec project, approach with vertical guidance (APV) procedures using EGNOS are being developed for three regional airports in the Czech Republic. APV procedures are also being developed for three former military airports.

“EGNOS provides good benefits where there is no ground infrastructure in place,” he said in reference to the disused military airports.

The Czech Republic also participates in the SESAR project, which is investigating the use of GNSS through all phases of flight.

“Satellite navigation is going to be one of the important elements in developing a new generation air traffic management system,” Hubert said. “We have concluded that the implementation of EGNOS can increase the safety of our operations, increase the flow of traffic and provide environmental benefits in terms of reduced noise, CO2 emissions and fuel.”

Upgrading to SBAS approaches

Benoit Roturier, the director of services for aerial navigation with France’s Directorate General of Civil Aviation (DGAC), said the country’s goal is to upgrade all airports with GPS non-precision approaches to SBAS approaches with vertical guidance.

He noted that the use of EGNOS and Galileo will help the country meet the request by the International Civil Aviation Organisation (ICAO) that all runways using instrument flight rules should also have approach procedures with vertical guidance by 2016 as a primary or back up means for pilots to land aircraft.

For European airports this means the use of either EGNOS to augment GNSS or a system known as barometric vertical navigation (Baro-VNAV), which is based on changes in air pressure with altitude.

“EGNOS is the forerunner for GNSS in Europe and for the European Space Policy, and is completing the aviation navigation infrastructure for approach and landing operations,” he said.

EGNOS augments the standard GPS signal by providing more precise location information. It also provides integrity data, informing users as to whether the GPS signal can be used or not at a particular time.

By itself, the US GPS is not accurate enough in the vertical plane to provide pilots with usable glide slope information for precision approaches when landing. By comparison, EGNOS’ achieves an accuracy of 95%, which translates into locating a position within 1-3 metres horizontally and within 2-4 meters vertically.

The half-day workshop Galileo Users Forum (GUF) workshop was hosted by the Czech Republic’s Ministry of Transport at Prague House in Brussels. The Galileo Users Forum was launched last year by the Czech Republic as a means of creating a network to determine how Europe’s satellite navigation system could be exploited in the EU.

The first meeting, held in September 2008, focused on the use of Galileo and EGNOS in the rail transport sector. The second, in July 2009, targeted the agricultural sector.

Updated: Mar 20, 2014