RPAS Procedures and Phraseology for Data Link Loss at Airports

The non-segregated integration of remotely piloted aircraft systems (RPAS) into the existing air traffic management structures, particularly at and around airports, is still an open task. The INVIRCAT project aims at developing a concept of operations for RPAS in the airport vicinity under instrument flight rules. Furthermore, the project assesses this concept through real-time simulations. One part of the simulation activities focused on the arrival of instrument flights at Düsseldorf international airport (EDDL). The simulation assessed the impact of the integration of RPAS on air traffic control, and the adequacy of procedures and phraseology for data link loss introduced by the developed concept. For this purpose, external air traffic controllers have been trained at the controller working positions and then been confronted with arriving RPAS. In case of data link loss, the RPAS were programmed to enter certain new determined contingency loiter areas separated from the regular arrival streams. After regaining the data link, the RPAS remained in the contingency loiter area until instructed by air traffic control otherwise. Voice communication between remote pilot and air traffic controller remained available through all simulation runs. Both remote pilot and air traffic controller were provided with suggested phraseology for the case of data link loss. During the simulation runs, the controllers were asked to indicate their perceived workload. After each simulation run, participants have been provided with a questionnaire, asking for their feedback on the applied and available procedures as well as the adequacy of the used phraseology. The workload was shown to be not affected negatively by the integration of RPAS. The event of a data link loss only temporarily and slightly increased the workload and quickly returned to lower values afterwards. Both the introduced procedures and the introduced phraseology were welcomed and rated to be adequate and useful for the purpose of safe integration of RPAS into terminal manoeuvring areas and airports under instrument flight rules.