In article 1,
Andrew Chaplin wrote:

Piotr Karocki wrote in news:XnsA390C0305C23pkarieeeorg@
193.110.121.168:

Joseph Testagrose wrote:
begin 644 UK2 TG283 DH DH108.jpg
end
What it has on wings?

Perhaps they are telltales for the study of airflow over the top of the
wing.

THey looklike tufts, for doing exactly that task.