Helicopter flight trials for European EGNOS (Forwarded)

ESA News
http://www.esa.int

18 July 2007

Helicopter flight trials for EGNOS

Successful trials have recently been conducted at Lausanne, Switzerland,
using the European Geostationary Navigation Overlay Service (EGNOS) to guide
a helicopter as it approached and touched down at an emergency medical
service landing pad in the city.

The adaptable, go-anywhere characteristics of helicopters make them ideal
for emergency services, but when visibility is poor their operations are
limited by aviation regulations. The accurate position reporting and
navigation system integrity checking offered by EGNOS will be a vital
service for anywhere, anytime rescue services -- as was demonstrated during
the trials.

The Lausanne trials were performed by Eurocopter, using their EC155
experimental all-weather helicopter (Helicoptere Tous Temps - HTT). The
trial programme was coordinated by skyguide, the Swiss air navigation
service provider and consisted of a number of validating approaches
performed by the HTT to a Helicopter Emergency Medical Services (HEMS) pad
located on the roof of Lausanne University Hospital.

The test team was hosted in Lausannes La Blecherette aerodrome by the Swiss
medical air rescue agency (Schweizerische Rettungsflugwacht - Garde Aerienne
Suisse de Sauvetage - REGA) who also participated in the flight tests.

The trial approaches were designed by skyguide for 6 deg and 9 deg approach
angles. Initial feedback from the test pilots indicates that, despite of the
steepness of the approaches -- the standard approach angle is 3 deg -- they
are easy to fly thanks to the three-dimensional guidance provided by EGNOS.
Vertical guidance for the pilot is a major advantage EGNOS offers over
standard GPS.

The increased approach angles also reduce noise nuisance on the ground as
the helicopter can remain at high altitude until it is closer to its
destination before commencing its final descent. In addition, a steeper
descent angle reduces the noise generated by the rotor blades as the craft
nears the ground.

The implementation of instrument approaches for HEMS operations will allow
the emergency services to continue their operations in weather conditions
that would otherwise ground their helicopters.

The trials were performed as part of the GNSS Introduction in the AviatioN
secTor (GIANT) project. GIANT is a European Commission Sixth Framework
Programme (FP6) project with the aim of supporting the introduction of EGNOS
and Galileo services into the aviation market while demonstrating to the
responsible authorities that the required safety levels are achieved.

The helicopter trials follow on from the fixed-wing EGNOS/GIANT trials held
at Valencia, in Spain, during late 2006. Additional GIANT flight trials will
be performed in 2007, at other European airports and on an oil rig in the
North Sea.

EGNOS is a joint programme of the European Space Agency, the European
Commission and Eurocontrol. EGNOS is made up of a network of more than forty
elements all over Europe that collect, record, correct and improve data from
the US Global Positioning System (GPS). The modified signals are then
relayed via geostationary satellites to users terminals, offering a
positional accuracy of better than two metres, compared with 15 to 20 metres
for GPS alone. In addition, EGNOS gives a guarantee of quality for these
signals that GPS does not provide.

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