An Approach to the Problem of Estimating Safe Separation Standards for Air Traffic

When studying the influence of navigational accuracy on collision risk, operating economy, or traffic organization it is necessary to distinguish between monitored and unmonitored traffic. With the monitored traffic the relative separation between aircraft is detected by the monitor and can be controlled by it. This is a closed-loop concept. With unmonitored traffic the separation is provided by procedural clearance of the flight plan. This is an open-loop concept.