In this article a final descent approach procedure is evaluated that performs near-idle descents of tightly sequenced arrivals over a curved approach path towards a single heavy loaded runway. An operational concept is applicable in which a Final Approach Spacing Tool (FAST) assists the Controller with advisories to maintain stability of the arrival flow. Calculated small subliminal control instructions are processed automatically, whilst other more significant required instructions are assumed to be given by the Controller. This process is modelled in MATLAB / Simulink, using an aircraft performance model with realistic modelled flight dynamics, including randomised uncertainties. Simulation results demonstrate significant stability differences for including or excluding assistance by subliminal control instructions. Also, the model gives indications for the maximum achievable runway throughput of an arrival runway in segregated mode fed by a dedicated flow of near-idle CDA operations. The achievable reactivity of the control loop is decisive to improve control on arrival sequence stability, whilst pro-active measures will help to increase the stability.