User's Manual Part 1

CAS / Part No. 9000000

SYSTEM DESCRIPTION AND INSTALLATION MANUAL

34-43-20

15 Feb 2003

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• Terrain Alert areas corresponding to the terrain that is causing a CPA caution or

warning.

Each of these features is explained in the following sub--sections.

(a) Terrain Display Background

The purpose of the Terrain Display Background is to provide overall situational

awareness to the crew about the relative height of the terrain near the aircraft.

The terrain is divided into ”slices” based on the elevation of the terrain with

respect to an aircraft reference altitude. Slices above or very near the reference

altitude are typically shown as varying shades of yellow. Slices safely below the

reference altitude are typically shown as varying shades of green or even black.

The reference altitude is a surface starting at the aircraft and propagating

forward along the aircraft flight path angle for 30 seconds. The reference altitude

surface then extends horizontally at the altitude the aircraft is expected to have

at that time (i.e., 30 seconds in the future).

The specific colors and textures used for the various slices, as well as the

threshold altitudes for the slices, are contained in the Aircraft Specific Database

(ASDB) and thus can be tailored for specific installations. Figure 1--26 shows a

typical color scheme and altitude definitions. (Note: The figure is drawn in color.

If this document is printed in b lack and white, the different yellow and green

textures representing different terrain elevations will appear as different shades

of gray.)

Figure 1--26. Terrain Slices