"Jeffrey Voight" wrote in message
...

I'm curious about something I frequently see. When I look up and see
contrails from airplanes, I often see more than one headed in the same
direction, but separated by some distance. I figure this is a result of
the trailing aircraft not wanting to fly along in the contrail left by
the lead aircraft and/or the wind pushing the contrail to the side prior
to the trailing aircraft. What I don't get is why I see them bend at or
about the same location. Is this the result of the wind changing
direction at this location? Perhaps the pilots are flying VOR to VOR
and that bend is where the local VOR is?


That is most likely.



I would have thought that most
flights at altitudes that produce contrails would be on GPS plans, so
I've discounted this theory a bit.


In heavy traffic areas aircraft are still tied to preferential routes along
airways regardless how they're equipped.