Satellite-based precision approaches at Frankfurt Airport

The German air navigation service provider DFS Deutsche Flugsicherung is pushing forward the implementation of satellite-based precision landing. In May, DFS and the Frankfurt airport operator, Fraport, signed a cooperation agreement for the installation of a Ground Based Augmentation System (GBAS) for Category I operations. The GBAS station manufactured by Honeywell will be installed in 2014. Thus, Frankfurt hub will be the first major international European airport to be equipped with GBAS. Additionally, in May 2013, DFS and Indra Navia implemented a GBAS trial station at Frankfurt Airport to test the technology and to support the validation of ICAO standards up to Category III approaches as part of the SESAR project 15.3.6.

"With GBAS, DFS is advancing a future technology and is an innovation pioneer worldwide. We are making an important contribution to increasing efficiency," explained Chairman and Chief Executive Officer of DFS, Klaus-Dieter Scheurle. “Since we introduced the first CAT-I-certified GBAS station in Germany at Bremen Airport in 2012, this technology has successfully proved its practicability.”

In the future – after developments and complete validation have been made so it can be used under CAT II and III conditions – GBAS technology is intended to replace the currently used instrument landing system (ILS) in keeping with relevant provisions of the International Civil Aviation Organisation (ICAO).

The costs for the installation and operation of the ground station for CAT I operations at Frankfurt will run to about five million euro.

The new technology boasts many advantages over the approach procedures currently used at Frankfurt Airport. Satellite navigation based on the US Global Positioning System (GPS) has a range of accuracy of about plus-minus ten metres. This level of accuracy and the integrity of the signal is not exact enough for precision landings in poor visibility. However, with the aid of a GBAS ground station, the required criteria can be fulfilled. The approaching aircraft can determine its position exactly and thus conduct its final approach safely and precisely. The signals transmitted by the satellite are received by the GBAS station which compares them with its own position and transmits a corrected signal to the landing aircraft along with approach path information.

The biggest advantage of GBAS is the number of different approach procedures that can be used with just one station simultaneously. Up to 49 arrivals, destined for various runways, can be supported by just one GBAS station.

To use the full potential of the system, it will be necessary to equip airplanes as well as install facilities on the ground. Some aircraft types are already fitted with GBAS receivers as the standard or an option, such as the Boeing 747-8 and the 787, or the Airbus 380 as well as the 320 family. Air Berlin, for example, has already installed GBAS on-board receivers in its Boeing 737 next generation fleet.

The system offers further advantages compared to ILS. For example, the GBAS station does not need to be checked by flight inspection nearly as often as an ILS. Eventually, the technology promises to deliver a marked increase in cost-efficiency as compared to the current ILS.