Cirrus SR22 Pilot Operating Handbook page 359

Cirrus Design
SR22
Glideslope Intercept and Tracking
1. Begin with a reliable ILS signal selected on the NAV receiver.
2. Select autopilot NAV and APR. Airplane must be within 50%
needle deviation of localizer centerline.
3. Select ALT mode. Airplane must be 60% or more below the
glideslope centerline during the approach to the intercept point. If
the above conditions have existed for 10 seconds, GS mode will
arm, the GS annunciator will come on and the ALT annunciator will
remain illuminated. When glideslope intercept occurs, the ALT
annunciator will go out and the system will track the glideslope.
If approach vectoring locates the airplane too near the
glideslope at the intercept point (usually the outer marker), the
GS mode can be manually armed by pressing the ALT button
once. Once capture is achieved, GS annunciator will come on
and ALT annunciator will go out.
Section 5 - Performance
There is no change to the airplane performance when the S-Tec
System 55X autopilot is installed.
Section 6 - Weight & Balance
There is no change to the airplane weight & balance when the S-Tec
System 55X autopilot is installed.
Section 7 - Systems Description
Autopilot
The airplane is equipped with an S-Tec System 55X two-axis
Automatic Flight
programmer/computer is installed in the center console radio stack.
The autopilot roll axis uses an inclined gyro in the turn coordinator
case as the primary turn and roll rate sensor. In addition to the turn
coordinator instrument, the roll axis computer receives signals from
the HSI and the #1 NAV/GPS radio. The roll computer computes roll
steering commands for turns, radio intercepts, and tracking. Roll axis
P/N 13772-108
Revision 06: 05-09-11
• Note •
Control System (Autopilot). The
Section 9
Supplements
autopilot
17 of 24