Garmin GFC 600 Pilot's Manual page 33

The pilot must add power to increase airspeed. If the aircraft was in GA mode prior
to entering Underspeed Protection and full power has already been applied, the pilot
can move the NOSE UP/DN wheel in the DN direction to reduce the pitch attitude
reference. Moving the wheel will cause the vertical mode to revert to PIT mode after
exiting Underspeed Protection.
When airspeed increases to 5 KIAS above the minimum speed, the AIRSPEED aural
and MINSPEED message will be turned off, and the armed vertical and lateral Flight
Director modes will change back to active. The autopilot will resume tracking the
previously selected vertical and lateral references.
NON-ALTITUDE CRITICAL MODES (VS, LVL, PIT, IAS, ALTS,
VNAV)
If the aircraft decelerates to an IAS below the minimum commandable autopilot
airspeed, the vertical Flight Director mode will change from active to armed and IAS
will become the active vertical mode and flash for five seconds. MINSPEED will be
displayed on the GMC 605. The autopilot will cause the aircraft to pitch down.
190-01488-00 Rev. B
GMC 605 Underspeed Indication
(Altitude Critical Mode)
GI 285 Underspeed Indication
(Altitude Critical Mode)
Garmin GFC 600 Pilot's Guide
AFCS
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