Localizer Approach Mode can be utilized to fly a LOC Approach (i.e., without a glideslope) or an ILS Approach (i.e., with a glideslope). When LOC Approach Mode is armed, Glideslope Mode will also annunciate as armed, regardless of whether or not a glideslope is available.
289: LOC Approach Mode Armed (Glideslope Mode Arms Automatically)
Once LOC becomes the active navigation source the localizer can be captured, provided the following conditions are met:
Aircraft heading is within 105° of the localizer course.
The aircraft is within 15 NM of the Final Approach Fix (FAF) but not past it, and tracking inbound.
The active waypoint is the FAF.
Localizer deviation is valid.
For LOC-only approaches (i.e., no glideslope provided/available), another vertical mode may be selected (e.g., VS or ALTV) for the autopilot to fly a stabilized approach. For ILS Approaches, if the pilot wants to fly the non-precision LOC Approach without capturing the glideslope, pressing the
NAV Key instead of the
APR Key will prevent glideslope capture. Again, another vertical mode may be selected to fly a stabilized approach.
