DeX Operations Manual V. 2.1
Page 39
to overlap. By the time the aircraft is 10,000 feet AGL, there is extensive cone-of-safety
overlap in most areas.
In order for the cones of safety to work properly, the aircraft profile must have the glide
range and glide distance parameters filled out. The glide range should be set to a
distance in nautical miles, and the Glide Altitude should be set to an altitude in feet.
Most Pilot Operating Handbooks have a simple chart in them, which show aircraft glide
performance, with the altitude and glide range given in these units.
If you know that your aircraft will glide 9 nautical miles when it is 6000 feet (that’s one
nautical mile) high, enter 9 and 6000 respectively in these boxes. This is typical of most
single engine aircraft. Also in order to see the cones display, cones must be enabled in
the view settings, airport tab, and the DEX must think it is at a particular altitude. To
preview the Cones of Safety display, you can put the DEX in Sim Mode at a particular
altitude.
View Settings And System Performance
The rate at which the DEX refreshes the screen and responds to user input depends to a
large degree on the display complexity. Ideally the DEX updates the screen once per
second, however this rate is dependant on the local airspace complexity, the zoom
range, and the number and type of features that are enabled for the current view. Some
map features are slower to draw than others. If the map seems to be drawing slowly,
consider turning off some of the following features (if they are on) or consider zooming
in to a smaller range.
Winds aloft vectors, State Lines, Highways, Lakes, urban area outlines, SFR’s, and
Class B airspace boundaries can be very busy in some circumstances, and are the main
causes of slow map performance. When customizing views, keep in mind that the more
of these features that are enabled, the slower the map update rate will become
particularly at long range zoom settings.
