Step

Action

1

Tune the ILS on the NAV RAD page of the FMS. Enter the frequency of the ILS as shown the following screenshot:

Hint: If you don’t know the ILS frequency from memory, you can browse through the navigation database using the FIX page on the FMS.

2

After the ILS frequency has been tuned, the Navigation Display mode changes to APP display mode, which has the following elements:

❶    In this example, this runway is going to be approached. It has a course of 142°. The extended runway center line is reached after flying course 225° for a while.

❷    The runway course pointer shows the direction of the runway.

❸    The deviation indicator is a bar, that shows by deflection in both directions how far the aircraft currently is from the extended runway center line. In this example, as the aircraft would approach the extended runway center line on course 225°, this bar would slowly creep to the center and the moment, when the aircraft reaches the extended center line, the deviation bar and the runway course pointer would fall in one line.

Alternatively, the APP display mode can also be activated manually at any time using the APP Selector (not to be mistaken from the APP button on the autopilot Mode Control Panel!):

Other display modes are MAP (to show the planned flight route) or VOR (similar like APP but to follow VOR radials without controlling the vertical channel).

Step

Action

1

Use the autopilot and its BASIC modes (SPD, TRK, ALT, VS, FPA or FLCH) to fly the first part of the landing pattern.

This means, that you first fly the downwind (❶), at the end of the downwind turn into base (❷) in order to fly a course, that intersects the extended runway center line.

3

Reduce SPD a bit coming from cruise. The SPD mode remains active until the Ardupilot LAND mode gets automatically activated.

4

While approaching the extended runway center line, arm the Approach-mode on the Mode Control Panel using the APP button (❸):

Once the APP mode is armed, both the glideslope and the localizer will be captured and followed automatically whenever either of them is intersected.

So, pressing the APP button, while the aircraft is on a suitable course to capture the ILS (and also has a suitable altitude), is the last manual action done by the pilot. From that point on the flight will continue fully automated and end with a full stop landing.

5

The autopilot is capable to capture the ILS localizer (❹) coming from any inbound course (even if e.g. a 170° turn is required). Regardless of the intersecting course, the moment, when the turn to the runway needs to begin, is exactly calculated to end up on the runway center line once the turn is completed.

Nevertheless, in order to fly a realistic and smooth ILS approach, aim to intersect the runway center line with an angle between 30° to 90° (in manned aviation 30° is common).

6

Ideally (and realistically) the aircraft is still flying level after the localizer has been captured and the glideslope is approached from below. As the APP mode is active, the aircraft will automatically capture the glideslope and begin the final descend as soon as the glideslope is intersected (❺).