Cirrus SR22 Pilot Operating Handbook page 271

Cirrus Design
SR22
Serials with Avionics Configuration B - 0002 through 1601, 1603
through 1643 and 1645 through 1662 without PFD:
These airplanes are equipped with an S-TEC System 55X Autopilot
with Altitude Selector/Alerter. The System 55X autopilot is a two-axis
autopilot system. The system consists of a flight guidance
programmer/computer, altitude encoder, altitude selector / alerter, turn
coordinator, and HSI. Mode selection and vertical speed selection is
made on the programmer/computer panel. A button on each control
yoke handle may be used to disengage the autopilot. The autopilot
makes roll changes through the aileron trim motor and spring cartridge
and makes pitch changes for altitude hold through the elevator trim
motor.
The SR22 installation of the S-Tec System 55X Autopilot features:
• Heading Hold and Command;
• NAV/LOC/GPS/GS tracking, high and low sensitivity, and
automatic 45° course intercept;
• GPS Steering (GPSS);
• Altitude Pre-select, Hold and Command, Altitude display, and
baro correction;
• Altitude and Decision Height (DH) alert; and
• Vertical Speed Hold and Command.
28 VDC for autopilot and altitude selector/alerter is supplied through
the 5-amp AUTOPILOT circuit breaker on the Essential Bus.
Refer to S-Tec System Fifty-Five X Autopilot Pilot's Operating
Handbook, P/N 87109 dated 8 November 2000 or later, Refer to S-Tec
Altitude Selector / Alerter Pilot's Operating Handbook (POH) P/N 8716
or P/N 87110 (no revision or later) for full operational procedures and
detailed description of operational modes of the Altitude Selector /
Alerter.
Avionics Configuration PFD - Serials 0435 and subsequent with
PFD:
These airplanes are equipped with an S-TEC System 55X or 55SR
Autopilot and are fully integrated with the Entegra PFD. Heading,
Altitude and VSI (55X only) reference bugs are provided to aid in
autopilot control and pilot situational awareness. When in an active
P/N 13772-001
Revision A10
Section 7
Airplane Description
7-97