Cirrus DESIGN SR22T Pilot Operating Handbook page 466

Section 9 Cirrus Design
Supplements SR22 / SR22T
Programmer / Computer
The Programmer / Computer, located in the upper section of the
center console, provides primary control of autopilot modes.
28 VDC for Programmer / Computer operation is supplied through the
5-amp KEYPADS / AP CTRL circuit breaker on MAIN BUS 1.
All Autopilot mode selection is performed by using the mode select
buttons and VS modifier knob. Available functions are as follows:
RDY - Ready Mode
Illuminates when autopilot is ready for engagement. When the
airplane's Battery Master switch is turned on and the rate gyro RPM is
correct, the RDY annunciation will come on indicating the autopilot is
ready for the functional check and operation. The autopilot cannot be
engaged unless the RDY light is illuminated.
HDG - Heading Button
When pressed, will engage the Heading mode, which commands the
airplane to turn to and maintain the heading selected by the heading
bug on the HSI. A new heading may be selected at any time and will
result in the airplane turning to the new heading.
NAV - Navigation Button
When NAV is selected, the autopilot will provide intercept and tracking
of GPS, VOR, and Localizer courses. For course intercept with full-
scale deflection, the autopilot automatically sets up a 45° intercept
angle at maximum gain and sensitivity. The point at which the turn to
capture the course begins is dependent upon closure rate and
airplane position. When the course is intercepted and the HSI course
deviation needle centered, the autopilot automatically initiates a
tracking gain program to reduce turn rate to 45% standard rate, and
then 15% standard rate.
GPSS - GPS Steering Mode
Pressing NAV twice will cause the autopilot to go to GPSS for
smoother tracking and transitions. When GPSS is selected, the
autopilot can be switched between heading and GPSS modes of
operation. In the heading mode, the converter receives a heading error
signal from the heading bug on the Horizontal Situation Indicator.
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Revision 01: 01-06-10