交通流の分散による航空機の近接通過頻度の軽減

Abstract

RVSM, which is the vertical separation minimum reduced from 2,000 ft to 1,000 ft at flight levels (FL) between 290 and 410 inclusive, was implemented on 30 September 2005 within the Japanese domestic airspace for efficient aircraft operation. Prior to the implementation, safety assessment for the airspace in assumed RVSM environments was carried out using the collision risk model. As a result of the assessment carried out in 2004, an estimate of collision risk averaged for whole target airspace met a maximum allowable level of collision risk, i.e. 2.5×10^<-9> [accidents / flight hour], called the technical target level of safety (TLS). However, a collision risk value for G581 route didn't meet the TLS. The G581 route system was restructured for reducing aircraft passing frequencies by traffic flow division. It's important to investigate the change in passing frequency values of the restructured airspace. Using flight progress data, the passing frequencies for the G581 route system were estimated every month. The results obtained are as follows. (1) An estimate of the collision risk after the restructuring for the G581 meets TLS. (2) The average passing frequency of post-restructuring is one twentieth of that of pre-restructuring.