Responsibility

Air traffic controllers are responsible for ensuring that separation minima are maintained. A loss of separation (LOS) event requires an adequate action to be taken by the controller to resume the required separation and to prevent an accident. When separation has already been, or is in the process of being, lost and the controller perceives a collision risk, there is no longer an issue of providing standard separation; the essential task is preventing a collision.

Scenarios

There are many hazards associated with incorrect or inadequate traffic avoidance instructions. In the case of loss of separation and Short Term Conflict Alert (STCA) alert, controller actions, delay or lack of action may lead to certain operational hazards such as: