Radio Altimeter (RA)/Radio AGL (RAGL)
The GHA only provides a radio AGL from 0 to 500 feet.
Radio altimeter functionality is optional. A radio altimeter must be installed and configured for this section to apply.
When the RA/RAGL height (aircraft altitude above ground level detected by the RA/RAGL) is between zero and 2500 feet, the current AGL value is displayed below the altimeter. Display of RA/RAGL height becomes more sensitive as the height above ground decreases.
|
Radio Height Range |
Shown to Nearest |
|---|---|
|
0 to 50 feet |
1 foot |
|
50 to 200 feet |
5 feet |
|
200 to 1500 feet |
10 feet |
|
1500 to 2500 feet |
50 feet |
When the RA/RAGL is selected as the altitude source for the minimum altitude alerting function, the color scheme of the minimums window is the same as the other barometric minimum alerts.
A ground line with diagonal stripes below it appears on the Altimeter to show the aircraft's height above the ground. If the RA/RAGL data becomes invalid, the message 'RA FAIL' is displayed in amber in place of the current AGL height. If a GHA is installed and data becomes invalid, the message 'RAGL FAIL' is displayed in amber in place of the current RAGL height.
