Each time the ping occurred it defined a possible arc (i.e. the aircraft is somewhere on that arc? Right we've all got that?
The next ping will give us another arc, the difference between arcs reflects the distance traveled. The aircraft has a minimum and maximum speed that allows the plane to move to the next arc. However the overall distance traveled to the last ping tells us the average speed, and I think we all agree it's unlikely to have done much other than cruise at this average speed...
So, collectively each arc and the next give us a track, right? If the arc doesn't change from one ping to the next the aircraft was either traveling along that arc or intersected it again, or was stationary. The over distance traveled/time will reveal whether the idea the aircraft was stationary at any time seems plausible - personally I doubt it.
Can anyone tell what is wrong with the above?