Today I had a flight programmed into KSFO using the ILS to 28R with ARCHI entry to the approach with the BDEGA3 arrival LEGGS transition. There a manual transition into the ARCHI waypoint from the arrival. I when I entered the manual transition I selected direct to ARCHI but instead the autopilot too the shortcut to DUMBA and as a result I couldn’t get low enough to catch the ILS. Can anyone explain why the autopilot didn’t go to the ARCHI waypoint and instead took a shortcut.
Hard to say without seeing a picture of your nav map and FMS legs when it happened. However if I had to guess I would say that when you inserted the direct, the angle was too sharp/distance too close to ARCHI, in which case the FMS will skip past ARCHI and make a single arc to the next waypoint, DUMBA.
I think you’re correct. If I had flown further on the manual leg I would have had a better angle turn to ARCHI. Thanks.