Thanks for the reply. Another thing I am finding strange is that they form criss cross patterns, which never used to be the case. Is there any way I can check what flights are overhead. I have checked on
Plane Finder ? Live Flight Status Tracker but they are not shown, so, can I rule out passenger flights?
Any advice on where I can get more information?
They do not seem the trails I am used to seeing elsewher as they tend to have a whispy spread.