In article . net,
"Steven P. McNicoll" wrote:
"JohnH" wrote in message
...
Then why don't airports use weathervanes instead of windsocks? 
Windsocks are a bit more useful to a pilot, they provide an indication of
wind direction and speed. Weathervanes provide only an indication of wind
direction.
I used to have a weathervane in the shape of a duck with wings that spun
around. You could get a good feel for how fast the wind was blowing by how
fast the wings were spinning around.
One day, after a storm, I discovered that the spinning wings could also be
used to estimate peak gust strength by their absence the next day.