Specifications

7-32 Information Manual
Section 7 Cirrus Design
Airplane Description SR20
Avionics Configuration 2.2:
The Sandel SN3308 combines the functions of an HSI, an RMI, a full
color moving map, a Stormscope display, GPS annunciator, and 3-light
marker beacon indicators. Compass information is derived from a
remote directional gyro and a flux detector. Redundant power sources
provide 28 VDC for system operation. Power is supplied through the 5-
amp HSI/PFD 1 circuit breaker on the Essential Bus and the 5-amp
HSI/PFD 2 circuit breaker on Main Bus 2. Either circuit is capable of
powering the Navigation Display.
The full-color display uses a rear-projection system driven by an active
matrix LCD display. The unit uses a halogen lamp as the singular
primary display projection light source. A separate dimming knob for
the display brightness is provided immediately below the display.
The HSI display shows heading and navigation information in a 360°
view similar to a conventional mechanical HSI, or in an EFIS 90° ARC
view. This includes compass card, heading bug, course pointer,
course deviation bar, TO/FROM indicator, glideslope indicator, and
flags. Heading bug and course pointer settings include digital readouts
that make it easy to set precise headings and courses. One button
operation allows primary navigation to be selected from up to four
different sources: two VOR/ILS receivers and two GPS receivers.
Either GPS1 or NAV1 may be selected as primary navigation sources.
Up to two bearing pointers can be displayed and switched to any NAV
receiver including GPS1, GPS2, NAV1, or NAV2. GPS2 and NAV2 can
only be displayed as bearing pointers, not as a primary navigation
source. The display is color-coded to indicate which navigation source
is selected: green for NAV1, yellow for NAV2, and red for GPS.
Auto Slew automatically turns the course pointer in response to
waypoint sequencing or Direct-To navigation from the GPS receiver
eliminating manual course changes at waypoints and reducing pilot
workload.
Heading and Course Sync allows the pilot, with one button, to
automatically set the heading bug directly to his current heading, or to
set the course pointer directly to a VOR station, simultaneously
centering course deviation. Course and heading command outputs for
autopilot operations are also provided.
March 2010