Cirrus Design Section 7
SR20 Airplane and Systems Description
P/N 11934-004 7-21
The HSI presents heading, turn rate, course deviation, bearing, and
navigation source information in a 360° compass-rose format. The HSI
contains a Course Deviation Indicator (CDI) with a course pointer
arrow, a To/From arrow, a sliding deviation bar, and scale. The course
pointer is a single line arrow (GPS, VOR1, and LOC1) or a double line
arrow (VOR2 and LOC2) which points in the direction of the set
course. The To/From arrow rotates with the course pointer and is
displayed when the active NAVAID is received.
The HSI heading reference bug is set using the heading selection
knob on the Flight Management System Keyboard. The selected
heading is displayed in a window above the upper LH 45° index mark
and will disappear approximately 3 seconds after the heading
selection knob stops turning.
The Course Deviation Indicator (CDI) navigation source shown on the
HSI is set using the CDI softkey to select GPS, NAV1, or NAV2 inputs.
The course pointer is set using the course selection knob on the Flight
Management System Keyboard. The selected course is displayed in a
window above the upper RH 45° index mark and will disappear
approximately 3 seconds after the heading selection knob stops
turning.
Vertical Speed Indicator
Vertical Speed data is provided by the Air Data Computer and is
shown as a vertical tape along the right side of the altimeter on the
PFD. The VSI scale is graduated with major tick marks at 1000 and
2000 fpm in each direction and minor tick marks at intervals of 500 feet
The vertical speed pointer moves up and down the fixed VSI scale and
shows the rate of climb or descent in digits inside the pointer. A
reference notch at the RH edge of the scale indicates 0 feet/min.
Vertical speed must exceed 100 feet/min before digits will appear in
the VSI pointer. If the rate of ascent/descent exceeds 2000 fpm, the
pointer appears at the corresponding edge of the tape and the rate
appears inside the pointer.
Magnetic Compass
A conventional, internally lighted, liquid filled, magnetic compass is
installed on the cabin headliner immediately above the windshield. A
compass correction card is installed with the compass.
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