RNAV平行経路の最小経路間隔の一推定方法

Abstract

An area navigation (RNAV) road map was prepared by the Japan Civil Aviation Bureau for effective aircraft operation and effective utilization of air space. Following the road map, RNAV routes have been implemented in Japan. RNAV is a method of navigation which permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self-contained aids, or a combination of these. This paper describes a methodology for estimating safe minimum route spacing for RNAV-approved aircraft. Radar track data of aircraft which flew on a Kagoshima RNAV standard terminal arrival route (STAR) were collected for six months for the purpose of analyzing the cross-track deviations for RNAV-approved aircraft. The distribution of cross-track deviations was estimated using this data set. A probability distribution model of it was then found. The lateral overlap probability was estimated using the empirical distribution and its deformation. Collision risk was estimated using the estimate of lateral overlap probability together with other given parameters. Comparing the estimated collision risk with the target level of safety (TLS) for the lateral dimension separation minimum, safe minimum route spacing was obtained. As a result, in the case that the population of aircraft with poor navigation performance, i.e., barely meeting the 95% containment requirement for RNAV approved aircraft, is assumed to be 10 percent, estimates of safe minimum route spacing are 8 nautical miles (NM) for RNAV1-approved aircraft and 32NM for RNAV5-approved aircraft, respectively. Additionally, safe minimum route spacing which takes into account of the fluctuation of data is estimated using the Bootstrap method. The result shows that the estimated ranges of minimum route spacing are 7NM-9NM for RNAV1-approved aircraft and 29NM-38NM for RNAV5-approved aircraft, respectively.