Ergonomical considerations
Enigma contains a very advanced LCD display that is able to perform well in direct sunlight
conditions. In order to achieve this and further ensure low power consumption, the display
contains a “light director”. This focuses the major part of available light towards the viewer,
creating a brighter image but also reducing the effect of ambient light falling at an angle
onto the display surface.
In order to take optimum advantage of this, the panel should be installed such that the
pilots eye will look onto the panel in a vertical -30 to +20 degree angle maximum. The
negative angle would be applicable for a steeply sloped panel where you would be looking
onto the panel from below.
This can be achieved in two ways: Mount the instrument as high as possible onto the
panel. This also aids the pilot as the image is closer to the windscreen avoiding eye fatigue
while constantly changing view from the panel to outside the aircraft.
If this is not possible or can only be done in a limited way, consider tilting the instrument up
slightly in order to aim the picture towards the pilot.
Idealized view of a sloped panel to optimize viewing quality. This image overdoes this
somewhat, in practice the panel does not have to be angled this much and if it is possible
to install the instrument relatively high on the panel, it is not normally required to mount the
instrument angled.
Preferred horizontal viewing angles are within left 50 degrees to right 50 degrees. If a
single instrument is to be shared between two pilots seated side by side, consider
installation of the instrument towards the center of the panel or alternatively angle it
towards the disadvantaged side somewhat. The panel can be read as angles greater than
+/-50 degrees but with reduced brightness.
