KMD 550/850 TERRAIN PAGE (EGPWS) OPERA-
Note: On some terrain displays, an indication of Geometric Altitude will
appear as GSL (Geodetic Sea Level). This altitude is the reference alti-
tude for the display and the terrain awareness algorithm. This reference
altitude is based on internally calculated Geometric Altitude and NOT
corrected barometric altitude that must be used when navigating within
the National Airspace System. Geometric Altitude is the height above
Mean Sea Level (MSL) derived from the GPS receiver, filtered by the
vertical figure of merits from the same GPS and complemented by short
term variations in barometric altitude. It represents the aircraft's calcu-
lated true height above MSL and serves as the reference altitude for
color-coding of the terrain display and the altitude input to the look-ahead
algorithm. Because it is primarily comprised of GPS altitude, this refer-
ence altitude will often differ from cockpit displayed corrected barometric
altitude. The Geometric Altitude is not to be used for navigation. It is pre-
sented to provide the crew with additional situational awareness of true
height above sea level upon which terrain alerting and display is based.
GPS altitude is an altitude above Mean Sea Level and it is the geodetic
height above the WGS-84 ellipsoid corrected by the geoid height in the
Rev 3 Jun/2004
MODE - Toggles between Warnings Inhibited and
Warnings Enabled. Not available in all installations.
RNGL/RNGM - Advances the indicator to the next
range. The upper button increases range, the lower
button decreases it. The EGPWS display ranges are:
1, 2.5, 5, 10, 20, 40, 80, 160, 320 nm. The selected
range is displayed in the lower left corner of the display
with the inner (half range) range ring distance dis-
played with the ring. The default range selected upon
power-up is 10 nm.
VIEW - Toggles between 360° and 120° views.
Note: When heading and track data are both invalid to
EGPWS, the terrain is displayed in a north up view. The
aircraft symbol changes to a plus symbol and the VIEW
power key label is unlit.
OVLY - Allows selection of flight plan, lightning or traffic
data for overlay on the terrain data. The GPS flight plan
data, lightning data and traffic data can be overlaid on
the terrain map, if the desired data is available
(Lightning and traffic data can be overlaid only if
heading data is available).
Outer Rotary Knob - Allows selection of TST (self
test), NRM (normal operation) or SET (settings) opera-
tion. NRM is the default. Not available in all installa-
KMD 550/850 Terrain Addendum