Climb, cruise, and descent speed reduction for airborne delay without extra fuel

The study extends previous research on linear holding strategies in cruise phases to absorb part of the air traffic flow management (ATFM) delays by allowing speed reduction (SR) on climb and descent phases too. Three different variants are analyzed, and the maximum airborne delay trajectories are computed by means of numerical optimization using an in-house trajectory generation tool, which relies on accurate performance models derived from manufacturer data. Results suggest that there exist differences on the tradeoff between fuel and time in various flight phases; therefore, including climb and descent into the SR strategy would enable the optimizer to use these differences to maximize the achievable time increase.