Note that given a number n of aircraft, all waiting to land on a runway, the problem of determining the sequence of landings, such that the time when the last aircraft lands is minimized, is a Hamiltonian path problem with n points. However, this is only a static version of a problem which in truth is a dynamic one: Over time the pool of aircraft available to land changes, as some aircraft reach the runway while new aircraft join the arrivals queue. Moreover, minimizing the “latest landing time” (or maximizing “throughput”) should not necessarily be the objective of optimal sequencing. Many alternative objective functions, such as minimizing the average waiting time per passenger, are just as reasonable. A further complication is that the very idea of “sequencing” runs counter to the traditional adherence of ATM systems to a first-come, first-served (FCFS) discipline. Deviations from FCFS raise concerns among some airside users about the