Geometric Altitude versus Measured Sea Level
An indication of MSL-G or Geometric Altitude may appear on the left
side of the MFD indicating the height above Measured Sea Level
(MSL) calculated from the GPS.
This data serves as the reference for color-coding for the Terrain
Awareness Display Page and as an input to the TAWS Look-Ahead
algorithm. Because it is derived from GPS, Geometric Altitude may
differ from corrected barometric altitude. Therefore, Geometric Altitude
may be in error by as much as 100 ft and should not be used for
navigation. MSL-G is presented solely to provide the pilot additional
situational awareness regarding the true MSL height upon which the
TAWS Terrain Display and Alerting is based.
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Revision 1: 12-15-07