# ATC Human Factors Involved in RPAS Contingency Management in Non-Segregated Airspace
## 1 Introduction  
Remotely Piloted Aerial Systems (RPASs) refer to aircraft systems that operate without a human pilot on board. The whole RPAS includes not only the aircraft but also the supporting ground control station and the communication infrastructure. The introduction of RPASs as a new element in the current air traffic control environment requires exploring novel ways to improve the RPAS pilot situational awareness, sensory awareness, and simplicity of operation through the intelligent use of automation and advanced human-machine interfaces (HMI). In addition to the RPAS pilot, human factors associated with air traffic controllers managing the airspace are also affected by a potential increase in the workload and the need to adapt to the new type of interaction. RPAS pilot-in-command (PiC) and Air Traffic Controller (ATCO) performance have been studied at various psychological, behavioural, and physical levels [1, 2]. Additionally, some researchers have evaluated human factor system interfaces from RPASs and comparedthem with approaches traditionally used to evaluate manned air vehicles, such as [3,4], where the authors identify differences between manned aircrafts and RPASs focusing on the fact that the pilot in command is physically remote from the aircraft. Furthermore, ongoing research investigates whether a simulated, unexpected, and manned flight event can be startling and explores differences in human responses between expected and unexpected manned flight events [5]. In [6], the authors evaluate the differences in separation management in airspaces classes from D to G and the role of Air Traffic Control (ATC) in maintaining safety, while in [7] a similar study was conducted for RPAS flying in TMA. Both used human-in-the-loop simulations and assessed the human performance of ATCO. However, there is still a lack of research on human factor approaches to integrate unmanned and manned flights in non-segregated controlled airspace safely. This study hypothesises that allowing an RPAS to operate into non-segregated airspace does not excessively increase the ATCO workload in surveillance-oriented operations, particularly in the case of unexpected RPAS contingencies. It is also assumed that at the initial phase of the RPAS introduction, the number of simultaneous RPAS in an airspace sector would be limited to a single vehicle (defined as the maximum RPAS capacity of a sector). It is therefore argued that if the workload increase remains within the capacity of the ATCO, a single RPAS insertion would be safe and the ATCO should be capable of managing the nominal RPAS mission operation but also a potential contingency. Thereafter, the rest of the manned traffic operating in the same sector must remain safe. It is well understood that managing any aircraft contingency using an ATCO would imply an increased workload. Moreover, depending on the complexity of the contingency, it may even occur that such an ATCO could be relieved from the duty of controlling other aircrafts to focus on the contingency aircraft entirely. Other ATCOs managing adjacent sectors or just some support ATCOs may assume that role for the contingency duration. This analysis is expected to prove that the ATCO workload increase would remain reasonable; therefore, RPAS contingencies can be safely managed. To validate our hypothesis, a set of complex operational scenarios has been created and evaluated in an extensive collection of real-time exercises. Active duty ATCOs have been tasked with managing realistic sets of manned traffic intermixed with a mission-oriented RPAS that may eventually suffer a contingency. Additional technology may improve the sharing of information between the RPAS and ATCO, thus increasing the overall situational awareness of both the ATCO and the RPAS pilot. Automatic Dependent Surveillance (ADS) technologies are surveillance technologies for tracking aircrafts and improving situational awareness. They are automatic because aircraft-related surveillance data are sent to the ATC controller without any action by the pilot.