Infringements of separation

If the distance between two aircraft is shorter than prescribed, this is called an infringement of separation minima. Today the automatic short-term conflict alert (STCA) system helps controllers to identify potential conflicts. The STCA alerts the controller in advance to prevent infringements of separation or to keep a proximity that has already happened as small as possible. The technology has been continuously upgraded over the years. Now it is capable of detecting even minor infringements of separation minima. In the past, two aircraft with a prescribed separation of five nautical miles passing each other at a distance of only 4.9 nautical miles would not have attracted attention on the radar screen. Today even the smallest of separation infringement is automatically recorded – even if the controller had the aircraft under control at all times and safety was not jeopardised. The operational system management investigates every infringement of separation, regardless of whether the occurrence was caused by controllers, pilots or failure of technical systems. The separation distances are intentionally set high. Even if the distance between the aircraft is “only” 4.5 instead of 5 nautical miles, there are still eight kilometres separating them.

The DFS safety management investigates every single infringement of separation in detail. In each case caused by DFS, we apply an assessment scheme which was developed by EUROCONTROL and to which DFS decisively contributed. Investigating each infringement of separation allows safety loopholes in the overall system to be detected and closed at an early stage.