Pilot's Guide

Garmin G1000 Pilot’s Guide for the Hawker Beechcraft C90A/GT/GTi
190-00663-02 Rev. B
404
AUTOMATIC FLIGHT CONTROL SYSTEM
UNDERSPEED PROTECTION
Underspeed Protectionis available when the optional ElectronicStabilityand Protection (ESP) system is
installedandtheautopilotison.Itisdesignedtodiscourageaircraftoperationbelowminimumestablished
airspeeds.
Whenaircraftairspeedreaches100knotsIAS,ayellowMINSPDannunciation(Figure7-7)willappearabove
theairspeedindicator.Whentheairspeedtrendvector(specictoeachapsetting)reachesapredetermined
airspeed,asingleaural“AIRSPEED”willsound,alertingthepilottotheimpendingunderspeedcondition.
Airspeed
Indicator
Figure 7-7 MINSPD Annunciation
Iftheaircraftcontinuestodecelerate,UnderspeedProtectionfunctionalitydependsonwhichverticalight
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, FLC)
Iftheaircraftdecleratestostallwarning,thelateralandverticalightdirectormodeswill changefrom
activetoarmed(Figure7-8),andtheautopilotwillprovideinputcausingtheaircrafttopitchdownandthe
wings to level.
Lateral and
Vertical FD
Modes Armed
Figure 7-8 Lateral and Vertical Flight Director Modes Armed
Anaural“AIRSPEED”alertwillsoundeveryvesecondsandared“UNDERSPEEDPROTECTACTIVE”
annunciation (Figure 7-9) will appear to the right of the vertical speed indicator. The pitch down force will
continueuntiltheaircraftreachesapitchattitudeatwhichIASequalstheIASatwhichstallwarningturns
off, plus two knots.