I have reproduced your flight.
The problem is Flight simulator’s flight plan management being unable to compute a route unless BOTH Departure and Destination are actual airports.
In your case you can set anything as the departure airfield, but the simplest is to just reuse the same airport as your destination : KSAN / KSAN
Once you have specified these airfields, you can choose your approach and it looks like this :
Flight simulator is trying to be smart by crating manoeuvres to properly join that route… it is failing miserably.
You do not want to go to that imaginary unnamed waypoint (because you are not actually coming from the airport), and you certainly do not want to fly that ARC (because this isn’t the IFR way to join a waypoint even if you did come from the airport).
Let’s take control over the navigation :
Click on the waypoint reprensenting the end of the segment you want to join and “Activate Leg to Waypoint”.
In the following picture : I want to join the Intermediate segment : SARGS to GATTO. So I click on GATTO and Activate the leg.
If you wish to join directly the final approach segment, select the waypoint representing the runway threshold. (Remember the logic : you want to join the final : the Runway is at the end of the segment you want to join, therefore, click on the runway)
Your HSI should update and the segment should change color. (BUG in FS : the segment being colored on the map is not always the actual segment used in the navigation : the actual segment used is the one with a magenta arrow in the flight plan).
Sometimes there is a bug in the game : the HSI will not update with the right course. Then select and activate an other segment to unlock it and try angain.
Now if you actually want to join the waypoint at the beginning of the segment, there’s a hint:
Don’t use the Direct To function : (it’s broken in the sim !)
But you can click on the waypoint and see the heading to that beacon, which you can plug in the autopilot’s heading selector.
Hint 2 : Don’t close that window with the “CANCEL D” button, that will break your route ! Use the Cancel menu button at the top right.
In the video you mention : don’t modify your nave on Autopilot.
Of course not : the whole point of the Autopilot is that you can let the autopilot fly the plane while you are busy punching keys.
Instead recommend this :
When modifying your navigation, ALWAYS switch your autopilot to HEADING mode, so that you can VERIFY that the new navigation is correct before allowing the plane to turn on it’s own.
In the real world : there’s this convenience feature in autopilots where they show you a preview of the new route on the map before you click on the Activate button. Unfortunately, Flight Simulator does not do it.
Hint : The Sync-Heading function is your friend
