are most useful for
helicopters which do a
lot of low-level flying in
cluttered environments, such
as air ambulances
EVS use an infrared camera, sometimes with a
visible light camera, to improve situational awareness.
For fixed-wing aircraft the infrared sensors are often
cryogenically cooled, which helps to exaggerate the
difference between the thermal return of the cameras
and enables the pilot to see with increased clarity.
Meanwhile SVS uses databases run by the FAA and
other aviation agencies to provide visual maps of
obstacles in the environment.
In its current iteration in fixed-wing aircraft EFVS is
typically presented to the pilot in the form of a heads-up
display (HUD) that appears in the pilot’s viewpoint.
However, a HUD is unlikely to function well in the
confined space of a helicopter cockpit, says Johnson.
“With helicopters you don’t have room for a HUD and
you might not have the room for cryogenically-cooled
sensors. So we’re investigating if we can use a more
compact sensor and use a head-worn display that moves
with your head.”
The reduced cockpit size is not the only the difference
between helicopters and fixed-wing aircraft that Johnson
and his team are having to deal with. Another major
difference is in how they takeoff and land.
“The EFVS rules that exist today apply to using the
technology on an instrument approach to a runway,” says
Johnson. “The rules help you use the vision systems to
acquire the visual references that you need to land –
runway lights and markings, the runway environment
and the wind sock.
“Landing of helicopters is a different problem and it’s
harder. With fixed-wing you land and stop, whereas
with helicopters you almost have to stop and then land.”
1 // Astronics’ Max-Viz 2300
Enhanced Vision System
(inset) was certified for the
Sikorsky S-76D helicopter in
72 JUNE \\ AEROSPACETESTINGINTERNATIONAL.COM