Garmin G2000 Pilots Guide - Page 498

SYSTEM OVERVIEW FLIGHT INSTRUMENTS Automatic Flight Control System If the aircraft continues to decelerate, Underspeed Protection functionality depends on which vertical flight director mode is selected. For the purpose of this discussion, the vertical flight director modes can be divided into two categories: Those in which it is important to maintain altitude for as long as possible (altitude-critical modes), and those in which maintaining altitude is less crucial (non-altitude critical modes). Altitude-Critical Modes (ALT, GS, GP, TO, GA) If the aircraft decelerates to stall warning, the lateral and vertical flight director modes will change from active to armed. The autopilot will provide input causing the aircraft to pitch down to maintain an airspeed no less than stall warning activation speed plus two knots, and the wings to level. An aural "AIRSPEED" alert will sound every five seconds and a red "UNDERSPEED PROTECT ACTIVE" annunciation (Figure 7-43) will appear to the right of the vertical speed indicator. EIS & CNS AUDIO PANEL AVOIDANCE MANAGEMENT FLIGHT HAZARD AFCS ADDITIONAL FEATURES Figure 7-43 Underspeed Protect Active Annunciation When airspeed increases (as a result of adding power/thrust) to above the IAS at which stall warning turns off, plus two knots, the autopilot will cause the aircraft to pitch up until recapturing the vertical reference. The vertical and lateral flight director modes will change from armed to active. Non-Altitude Critical Modes (VS, VNAV) If the aircraft decelerates to an IAS below the minimum commandable autopilot airspeed, a red "UNDERSPEED PROTECT ACTIVE" annunciation (Figure 7-43) will appear to the right of the vertical speed indicator. The vertical flight director mode will change from active to armed, and the autopilot will cause the aircraft to pitch down until reaching a pitch attitude at which IAS equals the minimum commandable autopilot airspeed. When sufficient power/thrust is available, the autopilot will recapture the previously selected vertical reference and the flight director mode will change from armed to active. Note: When the autopilot is outside normal operating limits, it uses more aggressive commands to return to normal limits. 484 Garmin G2000 Pilot's Guide for the Cessna T240 190-01263-01 Rev. A APPENDICES INDEX