Wind turbine study evaluated

DFS calculation method confirmed

05.08.2014.- At present, DFS Deutsche Flugsicherung will not change its calculation method for evaluating the potential disturbance of radio navigation aids caused by wind turbines. Recent studies, which had assumed a much lower level of disturbance, were carried out for the DVOR Michaelsdorf and raised some issues about the calculation method DFS uses. Therefore, DFS commissioned two prestigious international institutes to evaluate these studies. Both organisations came to the same conclusion. The measurements carried out at the DVOR Michaelsdorf were not sufficient to be taken as a basis for revising the existing calculation method employed by DFS.

Experts from Ohio University in the USA and the French Ecole Nationale de l’Aviation Civile (ENAC) did confirm the validity of the measurements themselves but questioned the conclusions drawn from the results. In particular, the studies' results cannot be generalised to apply to navigation aids other than the DVOR Michaelsdorf. The expert who conducted the study on the DVOR Michaelsdorf agrees with this as well. Both institutes agree that it cannot be concluded that wind turbines erected outside a three-kilometre radius around the DVOR Michaelsdorf would cause no appreciable disturbance of navigation signals.

Summaries of the expert opinions can be found here:

Ohio University Technical Memorandum (PDF)
DFS supports the ongoing dialogue on this topic between experts from around the world and is open to discussing new scientific findings. Until new conclusive findings are available or the International Civil Aviation Organisation ICAO changes its provisions, DFS will comply with the prescribed international standards to ensure the safety of air traffic.

DFS Deutsche Flugsicherung GmbH, the German air navigation service provider, is a State-owned company under private law with 6,049 employees as at 31 December 2013. DFS ensures the safe and punctual flow of air traffic over Germany. Around 2,000 air traffic controllers guide up to 10,000 flights in German airspace every day, and about three million movements every year. This makes Germany the country with the highest traffic volume in Europe. The company operates control centres in Langen, Bremen, Karlsruhe and Munich as well as 16 control towers at international airports in Germany. In addition, DFS is represented at the EUROCONTROL Control Centre in Maastricht, the Netherlands. Additional areas of activity include consulting, provided by the Aeronautical Solutions Division, and aeronautical data, grouped in the Aeronautical Information Management Division.