## 1 Introduction
[PERSON] and [PERSON] [25] concluded that the scheduled turnaround process is invariably disrupted when an aircraft does not arrive at its assigned gate or apron position on time. They proposed integrating time buffers during the gate allocation planning phase to increase system reliability. Their findings suggested that no systematic buffer concept is currently applied, with empirical experiences driving the process. Consequently, they developed a model aimed at optimizing buffer sizes relative to expected average delays. When discussing flight predictability, it is crucial to consider a wide array of information. Much of the prevailing research focuses predominantly on the development of predictive mechanisms using data linked to flight operations towards the end of a flight's trajectory [26; 27; 28; 29]. However, the current study distinguishes itself by considering a broader spectrum of information, potentially enhancing the depth and accuracy of the predictions. This research specifically engages with data related to flight operations across the entire trajectory, from the point of origin to the destination airport. Notably, it emphasizes the importance of trajectories flown and prevailing meteorological conditions. These trajectories are presented by tactical models integrated within the Enhanced Tactical Flow Management System (ETFMS). Governed by Eurocontrol, the ETFMS is a core element of the ATFCM [30]. The system generates flight profiles, beginning with the computation of a Filed Tactical Flight Model (FTFM) [30; 31]. This model, which includes a point and airspace volume profile, is the first depiction of a flight's intended trajectory. It aids in maintaining both the safety and efficiency of flights by enabling airlines and air traffic controllers to devise and synchronize strategies ahead of time, making necessary adjustments to adhere to the flight schedule. FTFM may evolve into a Regulated Tactical Flight Model (RTFM) [30; 31], which is created when the ATFCM measures, such as flight regulations along the projected FTFM profile, are needed. The RTFM ensures that the flight operates safely and efficiently, while minimizing delays and optimizing the use of airspace and airport capacity. Both models incorporate critical flight parameters, including the planned route, altitude, and speed [30]. Once a flight is airborne, a Current Tactical Flight Model (CTFM) [30] is continuously updated throughout the flight's duration [31]. Based on the FTFM or RTFM, the CTFM incorporates real-time changes in weather, traffic, airspace restrictions, and other operational factors, providing the best-known trajectory at any given moment. This model assists flight crews in making real-time decisions regarding changes to route, altitude, and speed, among other parameters. This study examines flight behavior along the entire trajectory to assess deviations from the planned performance, with the primary objective being the identification of key parameters influencing early or late arrivals. By analyzing these factors from departure to arrival, the research aims to deepen the understanding of the dynamics governing flight predictability, particularly for long-haul traffic. Due to limited radar coverage, a large portion of the trajectory remains a gray area, a situation expected to improve with future satellite coverage. However, pre-tactical predictability will continue to rely on anticipation, and without satellite communication, two-thirds of the trajectory on some intercontinental routes will still lack real-time positional reporting. Any deviations occurring within this gray area can put airport stakeholders in a challenging position regarding resource allocation. This ultimately affects the level of service provided to airlines and passengers. Thus, this research proposes enhancing airport operational performance through a service that provides predictions on in-block and landing time deviations by analyzing the flight's behavior along its entire trajectory.