ILS GLIDESLOPE FAILURE
Loss of ILS glideslope signal is indicated by the appearance of the GLIDESLOPE advisory window on all
MFDs and blanking of the glideslope needle on the ADI display and HUD. With this failure, you have the
choice of downgrading your approach to a localizer only, discontinuing the approach, or flying another
type of approach (TACAN, VOR, PAR, or ASR) depending on the situation and availability of approaches.
The GLIDESLOPE advisory legend will be removed if glideslope data becomes valid or the REJ button is
depressed on any MFD.
Figure 57 shows a glideslope failure on the ADI display and the HUD. Assuming that the glideslope data
remains invalid, the REJ button on any MFD must be pressed to remove the GLIDESLOPE advisory
window in this example. VOR/ILS receiver failuresee NATOPS, Chapter 21.
Figure 57: FAILED ILS GLIDESLOPE INDICATION