Helicopter Emergency Services deal with emergency
evacuations and inter-hospital transport across Europe.
Improved navigation information from EGNOS could mean
fewer cancelled flights due to adverse weather.

Although most modern helicopters have Instrumental Flight
Rules (IFR) capability this is not used because IFR are
not adapted to helicopter flight characteristics. As a
result almost all medical operations are still performed
under Visual Flight Rules (VFR). When visibility is
reduced, as in bad weather, the use of VFR creates a
risk factor in helicopter medical operations.

Any helicopter landing system must support steep glide
slopes and multiple legs but needs little or no ground
infrastructure. This rules out the conventional
Instrument Landing system meaning that systems relying
on the Global Navigation Satellite System (GNSS) are
required instead.

There are currently three options: GPS, EGNOS and
ground-based augmentation systems (GBAS). Of these,
EGNOS is the most appropriate for Europe because it
delivers a high level of performance and needs no
local ground installation.

EGNOS (the European Geostationary Navigation and Overlay
Service) is a joint project of the European Space Agency
(ESA), the European Commission (EC) and Eurocontrol, the
European Organisation for the Safety of Air Navigation.
It is designed to augment the two military satellite
navigation systems now operating (US GPS and Russian
GLONASS) and is paving the way for Galileo. The system,
now in its testbed phase and operational in 2004,
already improves the accuracy of GPS positions from
about 20m to 2m.

A very successful demonstration was organised by
Eurocopter last month as part of a programme to improve
the ability of helicopters to fly in adverse weather.
These trials validated the use of EGNOS on HEMS
helicopters.

Eurocopter fitted an EGNOS Test Bed User Equipment
(TBUE) receiver onto an EC 155-HTT helicopter. This
was coupled with the flight management system (FMS) so
that EGNOS-guided helicopter approaches could be shown.

These trials demonstrated the good quality of the
EGNOS signal despite the adverse electromagnetic
environment that is typical to helicopters because of
the rotating blades and other masking effects. The
TBUE receiver successfully enabled precise guidance,
both in manual and automatic piloting mode. The flight
path simulated a medical mission, including approaches
and transition to hover before final landing.

EGNOS can deliver real benefits to the Helicopter
Emergency Services (HEMS) helicopters by bringing
helicopter IFR approaches to reality. There will be
less noise at ground level, and it should be safer
to fly in adverse weather conditions. Crucially, a
more reliable service with fewer cancelled flights
means more lives saved.

Related news

* Sweden takes part in global navigation
http://www.esa.int/export/esaSA/SEM2O99YFDD_navigation_0.html
* A step closer to safer aviation in Africa
http://www.esa.int/export/esaCP/SEMYVC2A6BD_index_0.html
* Toulouse bus test-drives European satellite navigation
http://www.esa.int/export/esaSA/SEM4HZ1A6BD_navigation_0.html
* Space technology to help the blind
http://www.esa.int/export/esaCP/ESAKN58708D_index_0.html
* Safer harbour operations with EGNOS
http://www.esa.int/export/esaCP/ESA8KS7708D_Improving_0.html
* ESA is helping to make road transport more effective
http://www.esa.int/export/esaCP/ESACQ9THN6D_index_0.html

Related links

* ESA’s Navigation homepage
http://www.esa.int/export/esaSA/navigation.html
* EGNOS System Test Bed (ESTB) website
http://www.esa.int/export/esaEG/estb.html
* Galileo website (European Commission)
http://europa.eu.int/comm/dgs/energy_transport/galileo/
* Eurocopter
http://www.eurocopter.com/

More information

* What is EGNOS?
http://www.esa.int/export/esaSA/GGG63950NDC_navigation_0.html
* How does EGNOS work?
http://www.esa.int/export/esaSA/GGGQI950NDC_navigation_0.html
* Who’s involved in EGNOS
http://www.esa.int/export/esaSA/GGGYIA50NDC_navigation_0.html
* Who benefits from EGNOS
http://www.esa.int/export/esaSA/ESAG130VMOC_navigation_0.html
* Interoperability
http://www.esa.int/export/esaSA/ESAF530VMOC_navigation_0.html
* Satellite navigation today
http://www.esa.int/export/esaSA/ESA9IYZK0TC_navigation_0.html
* What is Galileo?
http://www.esa.int/export/esaSA/GGGMX650NDC_navigation_0.html

IMAGE CAPTIONS:

[Image 1:
http://www.esa.int/export/esaCP/SEMFR15V9ED_index_1.html]
Helicopter Emergency Services (HEMS) deal with emergency
evacuations and inter-hospital transport across Europe.
Improved navigation information from EGNOS could mean
fewer cancelled flights due to adverse weather
conditions. Credits: Europcopter

[Image 2:
http://www.esa.int/export/esaCP/SEMFR15V9ED_index_1.html#subhead1]
A successful demonstration was organised at Eurocopter
premises on 12 March 2003 in Marignane, France.
Attendance included representatives from the EGNOS
tripartite group, civil aviation authorities, and
helicopter operators. Credits: ESA

[Image 3:
http://www.esa.int/export/esaCP/SEMFR15V9ED_index_1.html#subhead2]
The experimental Eurocopter helicopter (EC 155-HTT)
was equipped with the Test Bed User Equipment (TBUE)
which was coupled with the Flight Management System
(FMS) to test manual and automatic approaches of 6-
and 12-degree slopes using EGNOS. Credits: Eurocopter