Investigation of Conflict Characteristics at Airway Intersections

Congestion of aircraft traffic along airways and in the terminal areas of large airports has significantly increased in recent years. To handle the new levels of congestion in the skies a better understanding of air conflicts is necessary. This paper presents a stochastic model that evaluates the number of conflicts for a spatial geometry of two intersecting airways. The stochastic nature of any desired parameter that defines aircraft location or performance characteristics is accounted for by the simulation process. The structure of the model ensures its efficiency in terms of computer resources as well as its accuracy. The effect of shape of the arrival distribution functions on the shape of the conflict distribution function and its variance was investigated. The variance of the number of conflicts is dependent on the aircraft-arrival distribution. This association is not a simple one, since an airplane on one path can conflict with more than one airplane on the other path. Thus the covariances in the variance term are dependent on the interarrival time described by the distribution. In a similar way the shape of the distribution function of conflicts was found to be dependent on the aircraft-arrival rate distributions.