T-45C TS & ADV BIFP-09
Loss of a valid ILS glideslope is signaled by appearance of the GLIDESLOPE advisory
box, and the glideslope needle on the ADI and HUD will become blanked. In that
circumstance, the pilot may elect to continue flying an ILS, but to a localizer-only; totally
discontinue the ILS approach; or transition to another type approach (VOR, TACAN,
PAR, ASR, VFR) depending upon the situation, availability, and location. If you change
to another type IFR approach, the approach minimums will probably change.
ILS LOCALIZER FAILURE 126.96.36.199.10.2
The FWD/AFT selection made on the HSI MFD determines which NAV control head is
active. The frequency entered by the pilot automatically determines whether the HSI
MFD displays an ILS or VOR legend.
Like VOR, ILS is only available and can only be selected in the HSI CDI mode. Once
ILS steering has been selected in the CDI mode, changing to HSI PLAN mode will
cause removal of the ILS course line and ILS CDI bar, but ILS steering needles will
continue to be displayed on both the HUD and ADI.
Loss of a valid ILS localizer is signaled by appearance of the LOCALIZER advisory box
and disappearance of the glideslope and localizer needles on the ADI and HUD. In that
circumstance, the pilot must abort the ILS and transition to another type approach
(VOR, TACAN, PAR, ASR, VFR). If the type IFR approach changes, the IFR approach
minimums will probably change.
ILS MARKER BEACON FAILURE 188.8.131.52.11.2
If an outer marker is incorporated in an approach, which is not always the case, the ILS
final approach fix (FAF) will be coincidental with that OM. If you lose the OM, you may
still be able to complete an ILS approach. It is allowable if the ILS approach plate also
gives TACAN/DME, radar, or TACAN crossing radials for determining the FAF from
which descent to MDA and missed approach timing are commenced, or missed
approached is also denoted with a DME.
According to the FAA, middle marker (MM) beacons are no longer required for ILS or
localizer-only approaches. Nonetheless, many MM beacons are still indicated on ILS
plates. The FAA says that they should be considered information-only assets. The MM
mayor may notbe positioned coincidentally with the published missed approach
point: ILS or localizer-only.