Paired t-test analysis to measure the efficiency impact of a flying RPAS in the non-segregated airspace

In the context of the ERAINT project, a number of human-in-the-loop simulations were conducted to study the implications of integrating a remote piloted aircraft system (RPAS) into the managed airspace. For the purpose of this study, the RPAS was assumed to be involved in surveillance missions, flying a large-endurance scan pattern. The area of surveillance was selected such that it crossed an active airway for approaches. Furthermore, the simulations also included situations in which the RPAS was involved in an emergency situation such as lost links and engine failures. From previous work, the results obtained from these simulations showed that the air traffic controllers (ATCs) could successfully manage the required separations for airspace safety assurance. Nevertheless, the number of total commands issued increased, in particular the number of requirements for altitude changes, and especially those destined to commercial aircraft. Given an aircraft's flying altitude impact on performance, one question rapidly arose: Is there an increase in flight costs for airlines as a result of the increased number of ATC commands issued to provide the necessary separation with the RPAS? For this purpose two metrics relating to time and fuel are defined such that they are targeted on quantifying the economic impact for commercial air traffic resulting from the presence of a RPAS. Both metrics are computed from the ADS-B traces of all aircraft in the sector and the results of each simulation are compared with those of a baseline simulation, in which the RPAS is not present. To improve on the comparison between each simulation's results we complement this study with a statistical analysis of the available data samples using paired t-test analyses to determine if the observed differences are statistically significant or simply due to random variability.