I believe the recommended obstacle-free zone was recently increased from 2 to 3 km radius for our kind of small airfields.
In any negotiations, it may be worth asking the developer to mitigate impact by making the new line more conspicuous (balls on top wire) and by lowering and painting pylons, as one sees in France.
The argument that if airfield "S" can cope with a transmission line (or other obstruction) near it then it's OK for all airfields to be similarly encumbered is often used by developers, but it is specious. The A75 euro-route has a level-crossing for dairy cattle near Dumfries, but that doesn't make a good case for adding such obstacles at intervals all the way from Istanbul to Belfast...
Last edited by N-Jacko; 11th Nov 2015 at 08:45.