Garmin Cirrus Perspective SR20 Pilot's Manual page 482

AUTOMATIC FLIGHT CONTROL SYSTEM
DESCENT
While flying the arrival procedure, the aircraft is cleared for descent in preparation for the approach to KCOS.
Three methods are presented for descent:
• Indicated Airspeed descent – Indicated Airspeed Mode can be used to descend to the Selected Altitude at a
constant airspeed. This descent method does not account for flight plan waypoint altitude constraints.
• Vertical Path Tracking descent – Vertical Path Tracking Mode is used to follow the vertical descent path
defined in the GPS flight plan. Altitude constraints correspond to waypoints in the flight plan. Before VNV
flight control can provide vertical profile guidance, a VNV flight plan must be entered and enabled.
• Non-path descent in a VNV scenario – A VNV flight plan is entered and enabled, however Pitch Hold, Vertical
Speed, or Indicated Airspeed Mode can be used to descend to the VNV Target Altitude prior to reaching the
planned TOD. Indicated Airspeed Mode is used in the example.
Indicated Airspeed descent:
1) Select Indicated Airspeed Mode:
a) Using the ALT SEL Knob, set the Selected Altitude to 10,000 feet.
b) Press the IAS Key to activate Indicated Airspeed Mode. The annunciation 'IAS' appears next to the Airspeed
Reference, which defaults to the current aircraft airspeed. Selected Altitude Capture Mode is armed
automatically.
2) Use the NOSE UP/DN Wheel to adjust the commanded airspeed while maintaining the same power, or reduce
power to allow descent in Indicated Airspeed Mode while the autopilot maintains the current airspeed.
3) As the aircraft nears the Selected Altitude, the flight director transitions to Selected Altitude Capture Mode,
indicated by the green 'ALTS' annunciation flashing for up to 10 seconds.
The green 'ALT' annunciation flashes for up to 10 seconds upon reaching 50 feet from the Selected Altitude; the
autopilot transitions to Altitude Hold Mode and levels the aircraft.
1
ALT Mode
Cirrus Perspective
468
Cruise Altitude of 12,000 MSL
2
Selected Altitude of 10,000 MSL
Figure 7-37 IAS Descent
by Garmin – Pilot's Guide for the SR20/SR22/SR22T
™
3
ALT Mode
190-00820-08 Rev. A