RADAR ALTIMETER FAILURE
With a failed radar altimeter, you lose your height above ground reference (Figure 53). If you are aware of
your location and the local terrain, this danger is minimized. If you have any doubt about your position or
the topography of the surrounding area, you should notify the controlling agency and immediately climb to
a safe altitude. Once you are sure of the local surface elevation and have confirmed that the standby
altimeter has the correct setting, you should be able to use it for all altitude references.
However, recall that where the radar altimeter supplies height above terrain, the barometric altimeter gives
height above sea level.
The radar altitude numbers are blanked if the radar altimeter fails and the aircraft attitude is not greater
than +/- 40 degrees in pitch or roll, or aircraft is higher than 5,000 ft AGL. The R is blanked if the radar
altimeter is turned OFF.
The procedure for dealing with a radar altimeter failure is:
1. Use the barometric altitude.
2. Confirm the correct altimeter setting.
3. Ensure that radar altimeter is not turned off by referencing the BIT page (Figure 54).
Figure 53: FAILED RADAR ALTIMETER
Figure 54: BIT PAGE