User's Manual Part 1

T
2
CAS / Part No. 9000000
SYSTEM DESCRIPTION AND INSTALLATION MANUAL
34-43-20
15 Feb 2003
Use or disclosure of information on this page is subject to the restrictions in the proprietary notice of this document.
1--75
A typical terrain background image is shown in Figure 1--27
Figure 1--27. Terrain Display Background
(b) Alert Line Display
The Terrain Hazard Display can also depict an Alert Line. The Alert Line is
drawn at the points where a CPA caution will occur if the aircraft continues along
it’s current vertical trajectory. When there are no CPA cautions or warnings
active, T
2
CAS TAWS will determine if an alert line needs to be drawn. Beginning
at the current aircraft position, T
2
CAS TAWS looks ahead of the aircraft to
determine where a CPA caution will occur. T
2
CAS TAWS will look up to 120
seconds into the future and look at all headings within 30 degrees of the current
aircraft heading. If any CPA cautions would b e triggered in this area, the alert
line will be drawn on the terrain hazard display.
Figure 1--28 illustrates the alert line. The alert line is the solid yellow line located
at about the 5 NM range ring. As the aircraft continued, this line (as well as the
background terrain) would get closer to the aircraft symbol. When the alert line
reached the aircraft symbol, a CPA caution would occur. Thus the alert line
provides the flight crew an advance indication of when CPA alerts will occur. The
alert line is not displayed when a CPA caution or warning is active.