A lot of this chat here is from US guys. Please help the rest of us here. I fly B737NG's. This was a night incident, which I expect therefore to be dark. Some have said it was a -300 or -700. Both have MAPs and IRS, VNAV & LNAV. Thus, how can the magenta line take you to the wrong place? I assume the destination was programmed correctly before departure. If this was a visual diversion from the STAR I assume the Clark airport had its RW lights on, otherwise how could there be a visual manoeuvre. But the MAP & PROG 1 and the NAV aid for approach into Branson would all have been screaming to 2 pilots that all was not as it seemed. What nav aids does Branson have, and what does Clark have?
If the VNAV had been set up for arrival at Branson then it would have showed >2000' error on the path. I don't know the relative positions of these airfields, but in one case there might have been a dive for the path, and in the other a reduction in ROC and an increase in power.
Please can some SWA locals explain to us how an LNAV/VNAV a/c can end up so far from the target.