Dynon Avionics EFIS-D10A Pilots Users Guide - Manual (Page 58)

HSI Operation
flying directly on course, your BTW and course lines overlap one another. The text area of the page contains a
numerical display of this bearing and a diamond icon to signify its symbol on the display.
The HS34 adds the possibility of having many more bearing sources in the system, so the behavior of the BRG
SRC button is dependent on how many devices you have connected. When you press this button, if you have
only one possible bearing source, the bearing source toggles on and off. If you have two or more bearing
sources, pressing the BRG SRC button highlights the first bearing source. Turning the VALUE knob allows you
to choose your bearing source from all options. Pressing the bearing source again chooses the second bearing
source. If you wait more than 5 seconds without adjusting anything or pressing any buttons, the selection self-
clears.
7. Scale indicator. This shows you what scale the CDI is using. Since
serial GPS streams do not indicate the correct scaling mode, this must
be configured manually with the "scale" button under the HSI menu.
The three options are "E" for enroute (5 n.m. full scale), "T" for terminal (1 n.m. full scale), and "A" for
approach (0.3 n.m. full scale). The current scale name and full scale range is indicated on the screen.
When the HS34 is hooked to a GPS unit via ARINC-429, the system can read the scaling from the ARINC-429
connection. When connected this way, the scaling auto-updates and follows the GPS. The indication on the
screen for mode and range should match the mode and range of the GPS at all times. When in this mode, the
range is not limited to just 5/1/0.3nm, as the GPS may slide between scales, so it would not be unexpected to
see a number such as 0.8 on the screen. Because of this behavior, on the final phases of an approach, a GPS
hooked to the HS34 via ARINC-429 acts much like a VOR receiver would with the CDI acting as angular
deflection, not linear distance. There are still only three master modes of Enroute, Terminal, and Approach,
which are annunciated on the screen.
8. Track indicator. This indicates your direction over the ground as reported by the GPS. This is
different than your magnetic heading when there are crosswinds present. Since this is your actual
EFIS-D10A Pilot’s User Guide 6-9