Abstract This paper analyzes the optimal level of operations on a single runway used only for arrivals. Two risks associated with landing procedures are the risk of a wake vortex encounter and the risk of simultaneous runway occupancy. We develop optimization models to maximize successful landing operations while mitigating these risk factors. The risks are mitigated by enforcing go-around procedures when separation distances are too small. In our capacity optimization, we assume that the goaround procedures are strictly enforced (making the operations risk-free) and their execution is absolutely safe. We develop two models as decision support tools which mimic the system dynamics and provide new insights into the landing process. One model maximizes the risk-free throughput (number of successful landings per unit of time) with and without wake-vortex effects. The second model accounts for dollar benefits and go-around costs in optimizing the system operations' level. This model maximizes expected net economic outcome (total dollar benefits minus total go-around costs) by adjusting the rate of landing attempts. Through these models, we calculate the maximum (risk-free) achievable throughput in the system. This provides a new definition of the landing capacity of the runway taking into account the probabilistic behavior of operations. Several numerical examples are given