Avidyne IFD440 - Precision Approaches

IFD400 Series Pilot Guide
5-24 Navigation
With the proper inbound course set, including on localizer or ILS
approaches where the course pointer is just for reference, the
course and glide slope deviation data will be transmitted as
appropriate from the IFD for display on compatible cockpit third-
party devices such as CDIs, HSIs, EFISs, etc. In the
ILS/Localizer case, the CDI deflection will be driven by the
localizer signal itself, regardless of the course setting.
PRECISION APPROACHES
VHF Based Precision Approaches †
On ILS/LOC approaches (Vectors-to-Final transition or the full
published procedure), the IFD will automatically toggle the nav
mode to VLOC when all of the following conditions have been
met for 5 consecutive seconds:
 The next leg or the active leg terminates at the FAF
 The aircraft is on the front side of the approach
 The aircraft course is within 15 degrees of the final
approach course
 Cross track deviation is less than half a dot
 The correct station is tuned and identified
Lateral and vertical deviation data will be transmitted by the IFD
for use by any integrated autopilot and external indicators.
Conversely, the IFD will toggle the nav source from VLOC back to
GPS when executing the missed approach at the Missed
Approach Point.
GPS Based Precision Approaches
Lateral and vertical deviation data will be transmitted by the IFD
for use by any integrated autopilot and external indicators. For all
models except IFD410, precision SBAS approaches are flown
with the nav source knob set to GPS (which will automatically
change to the GPS approach type). For IFD410, precision SBAS
approaches are flown when OBS has not been selected using the
nav source button.