Probabaly just an insurance cop-out driven by the increasing litigation-happy society we live in, premium mitigation and/or liability limitation should something hit the structure.
CAA impose a min height above which OL are mandatory (lest all buildings and telephone poles and such end up with OLs) However it would make some sense to fit them to power transmission pylons, culprits for many an accident - glowing corona isn't visible enough ! But hopefully not the strobe discharge lights as seen on some TV masts !
Last edited by b377; 17th February 2009 at 12:39.