Long post ahead, please bear with me. 🙏
I was just flying the A320 into KSAN, LOC runway 27, and noticed a strange bug. When I was about 20 miles out from KSAN, I opened the map to plug the LOC frequency into the autopilot’s NAV1 slot. However, when I tapped KSAN on the map and selected Runways, I noticed that the frequency shown on the map for KSAN LOC runway 9 was formatted differently from all the other approach frequencies I’ve seen in IF.
I didn’t think much of it at the time, so I just pressed “Set Nav 1”, returned to the virtual cockpit view, and switched the autopilot Nav Source from GPS to Nav1. At this point I expected the PFD to start displaying the localizer frequency and identifier in the lower-left corner, and for the LOC lateral guidance dots to appear below the artificial horizon, but they did not.
I knew I was lined up with KSAN runway 27, I had selected the frequency properly for the desired runway, and that I had switched to Nav1, so for grins and giggles I pressed the autopilot Approach button. Despite the localizer identifier and frequency not appearing on the PFD, the autopilot started lining me up with the extended centerline. I carefully monitored my approach all the way down and the autopilot kept me on course all the way to the threshold.
My first thought was that the IF navigation database entry for the KSAN runway 27 LOC frequency must be wrong, but if that were the case I assume that my autopilot wouldn’t have captured the localizer and kept me on course all the way to the threshold. I just don’t know enough about how the IF nav database, map airport info display, A320 virtual cockpit PFD, and autopilot do/don’t work together on the back end to properly diagnose this issue, but I know something is funky here.
P.S. Wasn’t sure where to post this, so hopefully I’m not screwing up anyone’s groove…