Cirrus DESIGN SR20 Information Manual page 233

Cirrus Design
SR20
control switches on the control yoke handles. The control knob
provides mode selection, disengage, and turn command functions.
The autopilot makes roll changes through the aileron trim motor and
spring cartridge and makes pitch changes for altitude hold through the
pitch trim motor and spring cartridge. 28 VDC for autopilot operation is
supplied through the 5-amp AUTOPILOT circuit breaker located on
Main Bus 1.
The S-Tec System Thirty Autopilot features:
1. Roll Stabilization.
2. Turn Command.
3. Heading Hold interfaced with DG or HSI coupled heading bug.
4. NAV/LOC/GPS tracking, HI and LO sensitivity.
5. Altitude Hold.
S-TEC System 55 / 55X Autopilot (Optional)
The optional S-TEC System 55 or 55X is a two-axis autopilot system.
The system consists of a flight guidance programmer/computer,
altitude transducer, 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 vertical speed
and altitude hold through the pitch trim motor and spring cartridge.
The autopilot operates on 28 vdc supplied through the 5-amp
AUTOPILOT circuit breaker on the Main Bus #1.
The SR20 installation S-TEC System 55 and 55X Autopilot features:
1. Heading Hold and Command.
2. NAV/LOC/GPS/GS tracking, high and low sensitivity, and
automatic 45° course intercept.
3. Altitude Hold and Command.
4. Vertical Speed Hold and Command.
• GPS Steering (GPSS) for smoother capture and tracking of
enroute or approach course (System 55X only).
P/N 13999-002 Info Manual
September 2011
Section 7
Airplane Description
7-71