Note:  Corresponding author: Thomas Günther, PhD, Chair of Air Transport Technology and Logistics, Technische Universität Dresden, 01069 Dresden, Germany. E-mails: firstname.lastname@example.org (T. Günther), email@example.com (M. Hildebrandt), firstname.lastname@example.org (H. Fricke), email@example.com (M. Strasser).
Abstract: The current paper stresses the high priority of accurate taxi time calculation and suitable pre-departure management strategies in the context of Airport Collaborative Decision Making (Airport CDM) and contributes to an improved overall understanding of the associated requirements. Based on data analysis performed at Frankfurt Airport this paper compares results of static and advanced taxi time calculation. Contrarily to static calculations, where look-up tables for stand-runway-relations are used, advanced taxi time calculation takes into account the current traffic situation and calculates taxi times dynamically. The paper shows that the taxi time uncertainties when using static data lead to only 42% of flights within the accuracy of ± 2 minutes according to the requirements of the Airport CDM Implementation Manual for short term predictions (maximum 30 minutes before off-block). The application of advanced taxi time calculation leads to significant improvements with 66% of flights within the accuracy of ± 2 minutes at the moment when the aircraft leaves the stand. Hence, app. 50% more predictions are compliant with the Airport CDM requirements compared to static data. Based on these results, the paper assesses the effects of improved taxi time predictability onto airport operation efficiency with particular focus set to taxi time reductions due to minimized queuing at the departure runway. It is shown that advanced taxi time calculation contributes to a reduction of delays, fuel burn, CO2 emissions and costs for airspace users compared to the use of static look-up tables. However, it is also emphasized that the shifting of delays from the runway holding positions to the stand does not necessarily contribute to efficiency improvements. It is recommended that the pre-departure sequencing strategy must be chosen cautiously in dependence on the fuel and time costs for airlines as well the amount of departure delay that has to be absorbed.