Due to the withdrawal from the nuclear energy programme and the concurrent need to reduce fossile combustibles and carbon dioxide emissions, many sources of renewable energy have to be installed. Among these are water and solar energy power plants, but to a large extend also wind turbine (WT) installations. In the end of 2016 as many as 27.270 wind turbines with a power of 45.900 MW had been installed in Germany (source: WindGuard GmbH). For efficiency reasons, WT become taller and taller and now reach that airspace, in which RADAR and terrestrial navigation systems operate. For safe operation…