# ATC Human Factors Involved in RPAS Contingency Management in Non-Segregated Airspace
## 5 Discussion  
This paper intended to complement the existing research on the human factors associated with the air traffic controller's performance when managing the insertion of RPAS in a non-segregated airspace. The research specifically addressed the definition of operational concepts and flight-intent technology to support RPAS suffering the most relevant flight contingencies, which are the failure of its engine and the loss of the command-and-control link with its remote pilot.  
We have analysed how the ATC workload is affected by introducing an RPAS operating within airspace sectors where traditional manned traffic is also flying. The ATC is responsible for allowing the RPAS operation and managing its potential contingencies while keeping the surrounding traffic safe.  
Besides using tools such as the NASA Task Load Index, Instantaneous Self-Assessment, and some aviation performance measurement tools, we have developed questionnaires to subjectively measure the ATC perception of the operational performance and workload variations when the RPAS is being managed.  
The results of our extensive real-time simulation campaigns allowed us to determine that: (1) the controller's workload is not significantly affected by the introduction of the RPAS within its airspace sector; (2) unexpected RPAS contingencies induce reasonable increases in the ATC workload values with respect to the baseline scenarios (no RPAS flying in the ATC sector/RPAS flying in nominal conditions); (3) ATC perceived the increase in workload as manageable, not endangering and only introducing limited efficiency penalties on the surrounding traffic; and (4) ATC perceives the use of the flight-intent technology as an important support tool to improve the safety and efficiency of operations. Furthermore,required improvements in the flight intent were identified, as well that, as in any new tool, it induces some additional workload until users become fully trained in its operation.  
Further research is needed to determine the RPAS characteristics that have more impact on the ATC workload and if appropriate human-machine interfaces can help to maintain workload levels into a low-medium threshold. More studies need to be conducted to know if the increasing RPAS vehicles or the increasing number of contingencies could negatively affect the workload and stress of the ATC and other involved humans such as the pilot-in-command.  
Conceptualization, A.R.-M., E.P. and C.B.; methodology, A.R.-M., C.B. and E.P.; software, P.R.; formal analysis, A.R.-M.; investigation, P.R.; resources, P.R.; data curation, C.B. and E.P.; writing--original draft preparation, A.R.-M.; writing--review and editing, E.P. and C.B.; visualization, C.B.; supervision, E.P.; project administration, E.P. and C.B.; funding acquisition, E.P. and C.B. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Ministry of Science and Innovation of Spain under Grant Number PID2020-116377 RB-C21 and by Eurocontrol under Grant Number EU-08-120916-C.  
Not applicable.  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
The datasets generated during the current study are available from authors on reasonable request.  
The authors declare no conflict of interest.