82002-PG-F
ST3400 TAWS/RMI PILOT’S GUIDE
PAGE 14
Virtual Approach Path
¥
and Safe Operating Area
¥
The ST3400 uses a VAP (Virtual Approach Path) to produce, internally, a
SOA (Safe Operating Area) within which the aircraft will normally fly on
approach to the runway. In this way the ST3400 can be actively scanning
terrain outside the normal approach path while minimizing false alerts
inside the approach path.
82002-PG-F
ST3400 TAWS/RMI PILOT’S GUIDE
PAGE 15
Predictive Altitude
¥
Display
The ST3400 implements a new display mode called PRED (Predictive
Altitude). It is especially useful in climbs where you want to know what
terrain you are actually out-climbing in the current aircraft configuration –
and what terrain you are not out-climbing. PRED displays the terrain
clearances in relation to the angle of the flight path of the aircraft. In
effect, you see what your terrain clearance will be
in the future
instead of
the present. This feature can be extremely beneficial in emergency climbs
in the vicinity of terrain.
During descents, the predictive altitude display has the benefit of showing,
well ahead of time, what terrain you are descending into. This may be
valuable when descending into a terminal area prior to landing or at any
time during a descent.
Topographic Display
The ST3400 also supports a TOPO (Topographic) view of terrain, in
sectional-chart colors. This display is useful to show the terrain situation
when at enroute altitudes when the other displays show no information. It
can also be a useful clue to turbulence encounters at altitude if the pilot is
aware of the wind direction.
Flight Plans
The ST3400 overlays the GPS/FMS flight plan over any terrain view, if a
flight plan has previously been entered into the GPS/FMS. The flight plan
overlay is for position awareness only and the information in the flight plan
is not used in the logic to control alerts or other functions. Because this
information is not used for this purpose, the ST3400 logic works equally
well during on-flight plan or off-flight plan operations without pilot
intervention. The flight plan is not shown when displaying the RMI or the
TFC screens.
In installations where the #1 GPS/FMS does not supply flight plan data to
the display, the flight plan from the #2 GPS/FMS will automatically be
displayed. Please refer to the AFMS for details on the specific installation
in your aircraft.
Airports and Runways
The ST3400 shows airports with runways greater than 2500 feet within
20nm of the aircraft position. In lower zoom ranges, the airport runways
