Encounter Rate Estimation of Continuous Descent Arrival Procedures in Terminal Area

Continuous Descent Arrival (CDA) provides economical and environmental benefits by eliminating a low altitude leveling off, which produces large noise impact and fuel consumption due to the high thrust compared to the idle descent. However, in the operational point of view, due to the difficulty of prediction, the separation management of the CDA operations is more difficult than that of conventional approaches with low altitude leveling off. Hence, besides its proven benefits, the risk assessment of the CDA procedures in the terminal area is necessary. An encounter rate has been used as a measure to assess a risk of the airspace. This paper describes a new trajectory-based methodology to estimate an encounter rate of the CDA procedure in the terminal area. The proposed methodology uses only system level information such as fleet mix distribution, traffic volume. It can also take into account any general speed profile and approach speed dependency on the landing weight. The proposed method was validated by comparing to the Monte-Carlo simulation result.