Risk Analysis of Positioning by Navigational Aids

The estimation of air traffic safety is based on determining the probabilities of negative events that may occur over a specified period of time. The concept of flight safety is based on the estimation of the risks of adverse events that may occur during a flight, compared with a certain level of acceptable risk. A significant component of the risk of aircraft deviation from the planned trajectory and the risk of aircraft collisions is risk of the positioning system lock. In the article under the risk of the positioning system lock, we consider the probability of the system's inability to determine the coordinates of its location within the limits of required performance under area navigation working at the point of aircraft location. The risk assessment model is based on estimated Total System Error (TSE) values for standby navigation systems by pairs of navigational aids: DME/DME, VOR/DME, and VOR/VOR. Performance estimation of probability indicator allows moving from the metric value of TSE to the percentage level of navigation lock risk, which allows to get more adequate reflection of navigation characteristics in assessing the safety of aviation in a particular airspace volume. The risk of navigation lock by navigational aids has been analysis for Ukrainian airspace as an example.