Dynon Avionics EFIS-D10A Pilots Users Guide - Manual (Page 54)

HSI Operation
Navigation Radio Overlay
The figure at right shows an HSI page with information sourced from a
navigation radio. This data could be a VOR or a localizer. The various
elements are described below.
1. Text displays. The text displays (located along the left side of the HSI
Page) provide a variety of information. Displayed here is the
course/OBS setting, the active frequency that the SL-30 is tuned to,
the identifier for the tuned frequency, and the bearing to the active
and secondary frequencies. When the data is not available or is not
valid, the various data fields in this area are replaced by dashes.
2. Course indicator. The green course indicator (shown pointing to 104º
at right) has an arrow at its end which points to the currently selected course (OBS) on your NAV radio. This
setting is also shown in the text area as "OBS." When tuned to a VOR, this is the radial that you wish to fly.
When tuned to an ILS, this is set to the runway heading. In a situation with no winds, keeping the course
indicator pointed straight up and in line with the heading pointer keeps the aircraft on course. This indicator is
fixed to the rotation of the DG, so it is easy to see which way you must turn to get on course. The course
indicator is only present when you are tuned to a VOR or a localizer. If the NAV radio indicates that you are not
currently tuned to an active frequency, this indicator is not displayed. The direction of this course is set
externally using the knob that is on the SL-30 when in VOR mode. When in ILS mode, the SL-30 disables the
OBS knob, and thus you must use the soft keys below the HSI in order to set the course.
When using the HS34 you can set the OBS using the COURSE knob. When properly configured, the HS34
sends course information to the NAV radio, just like a mechanical HSI or CDI does. When using an SL-30, the
EFIS-D10A Pilot’s User Guide 6-5