A previous post on this topic didn’t answer the question, so here is a new example – as clear as the sky on the day it occurred, see screenshot:
THE FACTS (see screenshot):
-> The IFR flight plan according to FlightAware (KSBA GVO MQO ROBIE AMEBY KSQL, as per table at the bottom of the screenshot) is pretty straight and has just two VOR-TACs, one reporting point and one waypoint on it.
-> The actual flight as indicated by the solid green line is pretty straight, as expected, reflecting a normal uneventful departure.
-> And yet, the dashed blue line shows this crazy zig-zag! None of the black dot “waypoints” FlightAware shows on the dashed blue line are on the flight plan, and the actual flight (green line) ignores them.
So what is this zig-zag all about – or by extension, what are the dashed blue line and the black dot “waypoints” all about?
A second example of where the blue dashed line appears meaningless (and I could show myriad more) is shown in the upper right corner of the screenshot, where someone is practicing approaches/holding patterns on KSBA runway 07. So here again, what is the meaning of the dashed blue line with the black dot “waypoints”?
P.S. Previous post that doesn’t answer the question is here: