The EU-funded Accepta project is helping airports, airlines and operators to develop and publish EGNOS-based airport approach procedures, and to equip aircraft to fly those procedures. At their first User Forum in Palma de Majorca, Accepta partners called for new participants to join the push for EGNOS in European aviation.
The EGNOS Safety-of-Life service (SoL) is now available, establishing EGNOS as the European satellite-based augmentation system (SBAS) for aviation, equivalent to the highly successful WAAS augmentation system in the United States.
However, airports still need EGNOS-specific landing procedures for their runways and aircraft need to be equipped with EGNOS-enabled receivers before they can use it.
"We need more EGNOS landing procedures to get more EGNOS users," said Accepta coordinator Luis Chocano of INECO, "but we need more EGNOS users to get more EGNOS landing procedures. The Accepta project wants to solve this chicken-and-egg problem."
One key element, he suggested, is to make sure airports, flight operators, and especially Air Navigation Service Providers (ANSPs) are better informed about the real benefits of EGNOS, including enhanced vertical precision and integrity, safer approaches and easier access to small or remote airstrips, and under difficult weather conditions.
The bottom line
The business case for EGNOS is an important part of the education process. Nick McFarlane of Helios Technology discussed an in-depth cost-benefit analysis carried out by his group. "The critical factor is what we call 'disruptions', meaning flight delays, diversions and cancellations, all of which are costly," he explained.
EGNOS can help reduce air transport disruptions. With its improved vertical guidance, EGNOS reduces approach 'minima', allowing pilots to get closer to the ground before having to decide whether or not to abort a landing. The end result is safer approaches and more on-time and on-target flights.
What it means: 'Minima'
'Minimum Descent Altitude' (MDA)
In non-precision approaches, this value is used to denote the altitude below which an aircraft must not descend unless the pilot can see the ground.
'Decision Height 'or 'Decision Altitude' (DH or DA)
DH/DA is very similar to MDA, except that it is used in precision approaches (Instrument Landing System – 'ILS'-based), while MDA is used in non-precision approaches.
Generally speaking, the greater the vertical precision of a particular navigation system or method, the lower the minimum decision or descent value, which means the closer a pilot can get to the ground before having to decide whether visibility is sufficient to complete the landing.
Looking at one particular case – Air Nostrum's fleet of CRJ900 aircraft – McFarlane said the initial investment needed to refit planes and make them EGNOS-capable would be fully compensated by the resulting reduced disruptions in less than three years.
The European GNSS Agency (GSA), which is supporting Accepta, is very serious about getting more EGNOS landing procedures published at quickly as possible, says GSA Aviation Market Development officer Hans de With.
"We want to encourage more and more users to adopt EGNOS. This will benefit them, as the business case we've discussed shows. But it will also benefit the public, making the air transport system more efficient. And this is why we are so pleased to see the Accepta project now moving into a new phase and calling for more participants," said de With.
New call for participants
A key moment for the User Forum came when Chocano announced the opening of the latest competitive call for new Accepta partners.
"We have €1.5 million in funding available for airlines, and aircraft and rotorcraft operators that are willing to equip their fleets with SBAS-capable avionics, and for air navigation service providers and airports willing to publish LPV procedures," he said.
Applicants must submit their proposals by the end of September 2011. Evaluations will proceed quickly, with work expected to begin before the end of 2011. For complete information on all aspects of the new call, 'EGNOS LPV implementation in Europe', applicants are invited to see the Accepta website (http://accepta.ineco.es).
Rick Farnworth of EUROCONTROL, a key promoter of EGNOS working closely with Europe's ANSPs, encouraged all relevant parties to join the project. "This is an important phase now for EGNOS. The system is here, it is working and we can actually do something with it."