The arrival is called an RNAV arrival. We have to use RNAV to follow it. RNAV is a combination of GPS and INS, so they can check on each other. The path accuracy of the RNAV system and the autopilot is about .05 (!) nautical miles. Yes, it is that good. Most pilots are not going to be hand flying on the arrival, so the path accuracy is basically dead on. However, once cleared for a visual, then maybe hand flying, maybe landing gear down to come down faster, turn away before turning back toward ONT as in Mark’s picture. I think you can assume no one is going to be turning toward ONT off the STAR because it is hard to come down fast enough if you shorten the path.
ATC can turn us east at any time for spacing.
The most objective question I think from Gary above is where do they clear us for a visual? Any time after the dogleg at hitop I think is realistic answer. Since the weather is good most days, it never rains in southern Ca…., most approaches are visuals, that is why the airplanes are below the altitudes and MEAs specified on the STAR.
I think David’s path is right on. since I was sitting on the left, and I could look down and see launch, that means the airplane was in between BB and CL.