82046-PG-B1
ST3400H PILOT’S GUIDE
Page 6-4
An AMBER CAUTION annunciation and requires
immediate
pilot
attention
.
A RED WARNING annunciation and requires
immediate
aggressive pilot action
.
Pilot reactions to alerts and warnings differ according to weather
conditions, visibility, type of warnings, phase of flight, and aircraft
performance considerations. Pilots should be thoroughly familiar with
FAA, company, or other approved operational procedures as required by
their aircraft and type of operation.
Pilots should train to react properly to all alerts, cautions and warnings, just
as one would train to react to any other emergency situation.
6.5
Alert Circle
6.5.1 Terrain
The Alert Area Indicator Circle shows the general location of the current
alert for FLTA alerts. Do not assume the terrain or obstacle threat is in
the exact center of the circle. Also, remember the circle only represents
the closest threat. Other threats may exist farther away, or to the side,
but will not be circled. Since the exact location of the terrain is subject
to uncertainties and tolerances, the terrain or obstacle threat may be
anywhere inside the circle.
6.5.2 Obstacles
For obstacle alerts, the size of the Alert Circle displayed on the
ST3400H depends on the ‘horizontal extent’ of the obstacle. This
includes both the radius of the obstacle and the survey uncertainty of the
obstacle as listed in the database. Tall obstacles are assumed to have
guy wires and will have a radius equal to their height. This means the
horizontal extent can be quite large for tall obstacles – for instance, more
than half a mile in diameter for a 2000’ tower..
An alert is generated to the obstacle horizontal extent, which may be
larger than the obstacle icon on the screen. If you see a tall tower
symbol the circle is a minimum of 1000’ in diameter.
When an alert is generated, the alert caution/warning circle will be
the
full diameter of the horizontal extent.
Stay completely out of the circle
as you will likely not be able to see guy wires if they are present.
It is possible that a tall obstacle, while not precisely in the aircraft’s
flight path, will generate an alert with an alert circle that
will then be in
the aircraft’s flight path
unless corrective action is taken. See
