Helicopters Deploy GNSS in Europe (HEDGE) is a project to develop and demonstrate new helicopter approach procedures as well as other EGNOS applications for general aviation. EGNOS (the European Geostationary Navigation Overlay Service) augments GPS to make it more accurate and increase its integrity and availability for aviation applications.

The project builds on the experience and knowledge gained through the GIANT (GNSS adoption in the aviation sector, FP6) project. HEDGE is sponsored under the EU’s Seventh Framework Programme (FP7).


The objectives of HEDGE are:
  • To develop the helicopter SBAS Offshore Approach Procedure (SOAP) procedure, including necessary avionics, and to successfully demonstrate it to the user community.
  • To develop helicopter Point In Space (PINS) procedures for mountain rescue and Helicopter Emergency Medical Services (HEMS), and to successfully demonstrate them to the user community.
  • To demonstrate fixed wing EGNOS based Approaches with Vertical Guidance (known as APV SBAS) in Poland.
  • To demonstrate an integrated navigation/surveillance concept in Switzerland.

Expected benefits from HEDGE

This project will significantly help the aviation industry by:
  • Progressing new EGNOS enabled helicopter applications that will enhance safety and increase the commercial viability of helicopter operations. It will undertake technical and standards work to mature these new operations, and it will demonstrate them to the relevant user communities.
  • Demonstrating APV SBAS approaches for small aircraft and General Aviation. The demonstrations will aim to bring in new users in Poland that have not yet been involved in EGNOS.
  • Demonstrating a “total system concept” using EGNOS for navigation and surface/airborne surveillance. EGNOS has the future potential to support multiple aviation applications, by providing both navigation and surveillance data.

HEDGE demonstrations and flight trials

Mountain rescue approach

Air rescue helicopter operators are only able to fly during the day and in good visibility, unless they land at a heliport offering instrument landings. The new EGNOS GPS Augmentation Systems will allow them to fly under a greater range of daylight conditions and visibilities. It is for this reason that Mountain Rescue operators are very interested in this new system, expecting more operational flexibility and an increase in safety. Within HEDGE, the partners will certify the Eurocopter 135 helicopter from TAF Helicopters for EGNOS and conduct demonstrations of some LPV approaches to the Viella heliport with the certified equipment.

Oil rig SOAP approach

The SOAP procedure is a new procedure based on EGNOS navigation that is designed for use in offshore operations. It will be demonstrated at a North Sea Oil Rig. Overall, this task aims to provide evidence to the oil industry of the benefits of the new SOAP procedure for offshore helidecks. The demonstrations will also show the benefits of using EGNOS for flight guidance and what this means for these operations.

Helicopter Emergency Services (HEMS) approach

On HEMS missions, helicopters sometimes have to fly under poor meteorological conditions and at any time of the day. Air rescue operators are very interested in using new aiding systems, such as EGNOS, to provide instrument guidanc eduring these operations and make them safer. The use of EGNOS will expand the range of meteorological conditions that the helicopters can fly in and should incrase safety. The HEDGE team aims to certify the Agusta 109 helicopter from Rega (a Swiss helicopter operator) and perform LPV approaches with the certified equipment. The helicopter already contains a certified EGNOS receiver, so no avionics updates is necessary.

General aviation APV

Mielec Airport (Poland) has only a NDB aid installed and the access to the airport is limited by this unique navaid. The use of EGNOS in this airport will make LPV instrument approaches here. These are expected to be safer than NDB NPA and with lower minima. Flight trials are planned to be performed with a Piper PA-34 Seneca II.

Navigation/Surveillance concept demonstration

This demonstration will show the use of EGNOS within an ADS-B system in which an equipped helicopter interacts with an existing ground station. REGA will provide an Augusta Westland AW109SP. The desmonstration will make use of a specially developed platform that integrates a Garmin GNS480 together with a CDI/VDI.

Avionics data gathering

EGNOS reception on helicopters will be monitored using several helicopters carrying GNSS receivers and dataloggers. Data will be recorded and analysed to determine if there are any issues with EGNOS performance for helicopter operations.