My dad said that when he landed at P-Y-DO International airport in Korea they used a logging chain as a wind sock.
From what I remember from his stories is it was above the 38th parallel on a little island. He said if the logging chain was blowing sideways more than 45 degrees in the wind, they would advice no take off or landing, if it was just blowing a little it was OK.
It is hard to find anything about P-Y-DO on the internet. It was a secret radar and listing station.