DFS rejects accusations by wind energy industry

28.08.2019.- Project developers and operators of wind turbines in the region of Hannover, Peine and Hildesheim have published an open letter requesting an end to the ban on wind energy to contribute to climate protection. DFS Deutsche Flugsicherung has rejected the accusations made in this letter. The criticism refers to omnidirectional radio beacons, which are crucially important navigation aids. Therefore, they are no obstacles but vital to ensure air safety.

“We do not block the switch to sustainable energy. On the contrary, we support the expansion of wind energy wherever possible. We never generally refuse permission to build a wind turbine within the protected area around a navigation aid,” said Klaus-Dieter Scheurle, Chairman and Chief Executive Officer of DFS Deutsche Flugsicherung, when commenting the allegations made by the wind energy industry. “In the course of the permission procedure, our specialists assess each request within these areas individually to determine whether the construction measure would impair air safety and might therefore not be permissible.” The decisive factor is the impact of the wind turbine on the reliability of the signal transmitted by the navigation aid. If the wind turbine deflects and distorts the signals beyond a permitted measure, they become inaccurate and can no longer be used.

The criticism of the wind energy sector that rejection practice at DFS generally prevents any wind energy projects within a 15-km radius around omnidirectional radio beacons is unfounded. It is true that with the expansion of wind energy to almost 30,000 turbines in Germany, the number of these facilities within the protected areas around radar and navigation aids is steadily increasing. Currently, there are approximately 2,100 wind turbines within the protected areas of omnidirectional radio beacons of DFS, i.e. within the 15-km radius. At some locations within the Hannover region, the number of wind turbines has reached the permitted limits. In the protected area of the omnidirectional radio beacon Leine/Sarstedt, which is used for arrivals to and departures from Hannover Airport, there are almost 115 wind turbines. By comparison, there are only around 40 wind turbines in the entire territory of Switzerland. One of the reasons why DFS has to reject additional wind turbines within protected areas is this density of turbines which puts the prescribed accuracy of air navigation facilities at stake.

The other accusation of the wind energy sector that the ground navigation systems of DFS are outdated technology is not true either. Although many aircraft already use satellite navigation, the ground-based navigation aids continue to be required. Many aircraft still navigate by means of terrestrial navigation facilities and an obligation to use satellite navigation does not yet exist. In addition, DFS has to provide ground-based navigation aids for an indefinite period of time as a fall-back system in case the satellite system (GPS) fails. The aircraft operating manuals explicitly list omnidirectional radio beacons as part of the navigation infrastructure. The manuals state that these beacons are important to contribute towards accuracy, integrity, availability and continuity of the aircraft’s position.

With regard to the size of the protected areas, DFS follows the recommendations of the International Civil Aviation Organisation (ICAO). According to these recommendations, the size of the protected area can be adapted to the existing interference, e.g. by existing wind turbines. As a result, DFS has defined a radius of 15 km as the protected area around the majority of its omnidirectional radio beacons. When assessing the effects of a wind turbine, DFS uses a mathematical method. Its validity was confirmed by the Federal Administrative Court in Leipzig in 2016 in the last instance.

The required signal accuracy of radar and navigation aids is also determined in the standards and recommended practices published by ICAO. This accuracy is becoming increasingly important because the airspace above Germany is busier than ever. This year, a new record high of approximately 3.5 million flights is expected.

“Any concessions to the wind energy sector which compromise safety are out of the question. We have the statutory obligation to guide air traffic safely through German airspace. We must ensure that air traffic controllers have access to reliable radar information, and that pilots can adhere to the prescribed routes when navigating,” that’s how DFS CEO Klaus-Dieter Scheurle summarises the situation.

DFS Deutsche Flugsicherung GmbH, the German air navigation service provider, is a State-owned company under private law with 5,400 employees as at 31 December 2018. 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, more than 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 control towers at the 16 designated international airports in Germany. The subsidiary DFS Aviation Services GmbH markets and sells products and services related to air navigation services, and provides air traffic control at nine regional airports in Germany and at London Gatwick Airport and Edinburgh Airport in the UK. www.dfs.de