FAA Approved Airplane Flight Manual Supplement

190-00716-03 Rev. 4 Hawker Beechcraft King Air 300/300LW
Page 147 of 167
TAWS AND GPWS
Refer to the GARMIN Pilot’s Guide and Cockpit Reference Guide, P/N 190-01343-01 and 190-01344-01
Rev. A or later FAA accepted revision for complete detailed descriptions of the GARMIN G1000 TAWS
and GPWS system functions and operating instructions.
Most of the G1000 Class A TAWS and GPWS functions depend upon either GPS or radar (radio) altitude
to function properly. The Altitude Voice Callout (VCO) GPWS function is one of the few that may use
both altitudes for normal operation. Because of the unique functional nature of the VCO function, its
description is contained in this section.
VCO Description
The advisory aural Voice Callouts (VCO) are part of the TAWS GPWS functionality. In Class A TAWS
configurations, aural altitude callouts “Five Hundred,” “Four Hundred,” “Three Hundred,” “Two Hundred,”
and “One Hundred” are generated based on inputs from the radar altimeter and GPS altitude. When the
aircraft is more than 5 NM from an airport, the VCO messages are triggered solely on radar altitude and
will not function if radar altitude is unavailable.
Inside of 5 NM to an airport, the callouts are based on the airplane’s GPS altitude above the runway
threshold as obtained from the G1000 aviation database. Loss of GPS may cause VCO messages not
be issued. If a flight plan was loaded in the G1000 at the time of GPS signal loss, VCO messages will
not be issued. Conversely, if no flight plan was loaded at the time of GPS signal loss, VCO messages
will be provided.
In Class B TAWS configurations, VCO issues the “Five Hundred” aural message only . The messages
are based only on GPS altitude, even if the aircraft has an operable radar altimeter. VCO messages are
not
available when the system status annunciations shown below are posted.
System Status
Type
Visual
Annunciation
Aural
Annunciation
TAWS System Test in Progress
None
TAWS System Failure
“TAWS System Failure”
TAWS Not Available
“TAWS Not Available”
VCO callouts are inactive at the initialization of the TAWS-A or TAWS-B system. When the aircraft’s
height above terrain exceeds 675 feet, the function becomes enabled and is provided during all flight
phases. Alerts are issued, one time only, when the height above terrain becomes less than 500 feet
down to 100 feet (TAWS-A), at which time the VCO is disabled until the aircraft climbs at least 175 above
the altitude associated with the last VCO callout that was issued. VCO alerts cannot be inhibited in any
TAWS configuration.