Modeling of urgent ATCO-Pilot communications in en-route airspace

The Air Traffic Management (ATM) system is currently undergoing modernization. Within the SESAR framework, new concepts are being proposed, researched and developed in Europe. Before implementing a new concept, it is crucial to validate it. In the validation process the performance of a safety study is paramount. The goal of this is to verify that the implementation of the new concept does not result in a degradation of safety levels within the ATM system. A key element of the ATM system is the human factor. The primary role of the air traffic control officer (ATCO) is managing the separation between aircraft, achieved through effective ATCO-Pilot communications. Currently, most communications are conducted through voice, especially in emergency situations. In many safety studies, the communication variable is crucial and must be accurately considered. No recent studies have used a statistical model to analyze ATCO-Pilot communications. Therefore, this study aims to model ATCO-Pilot voice communications in an en-route airspace, covering both standard and emergency situations, using actual communication recordings. The results indicate that ATCO communications under standard circumstances can be approximated by a lognormal distribution (Ln) with mean and standard deviation parameters (expressed in seconds) of Ln(3.94; 1.20), whereas the Pilot communications in these scenarios follow a lognormal distribution with parameters Ln(2.78; 0.95). Conversely, in emergency situations, these communications can be modeled with a normal distribution N(3.05; 0.68) for the ATCO and a lognormal distribution with parameters Ln(2.46; 0.69) for the pilot. These results will benefit future research where the communication factor is a key element and accurate modeling is essential.