Comparison of Generated Flight Delays in Continuous Descent and Step-down Approaches

It has been proven that using continuous descent approach (CDA) instead of step-down approach has advantages such as less fuel consumption, less noise pollution and also less flight time per flight. However, applying either CDA or Step-down approach to group of aircraft approaching an airport requires de-conflicting flights and maintaining safety. Implementing such tasks result in inevitable delay times which can reduce airport capacity and eventually yield in airport saturation. In this paper, a comparison is done between the total generated delay of the same group of aircraft approaching an airport in separate cases of step-down approach and CDA. To do so, a novel iterative method is used to carry out the necessary sequencing and scheduling of the conflicting aircraft with the aim of de-conflicting flights, maintaining safety and minimizing total delay. Results show that in most cases; CDA leads to more overall system delay than step-down approach. This important outcome is a disadvantage of CDA and must be considered alongside its environmental and economic advantages.