## 3 Results and Discussion  
### Real-Time with Harware and Humans in the Loop Simulation Environment and Test Methodology  
The paper addresses the description of very complete and accurate real-time with hardware and humans (pilot and controller) in the loop simulations performed in a complex laboratory environment [14]. The figures reported here were generated (using MATLAB) in the post-flight data analysis by processing the real-time simulation data that were stored in the flight data recorder used in the laboratory environment. The aircraft model was a very accurate, complete 6 DoF (6 Degrees of Freedom) model. In addition, atmospheric disturbances replicating real flight, as well as traffic, were considered in the overall simulation environment, which connects the ownship 6 DoF simulator, the traffic simulator, and the outside world (atmospheric) simulator in the same framework. In addition, the ATCo instructions were provided in real-time by real air traffic controllers using their controller working positions (CWPs) connected to the real-time simulation environment. Finally, the remote pilot was a real human pilot commanding the ownship with a dedicated RPS, by means of which the pilot could guide the ownship in augmented mode or using the real autopilot panel implemented in the RPS that was installed in the real-time laboratory environment. What follows is a description of the overall environment used for the real-time simulations (RTS). The primary components of the RTS laboratory environment were:  
* The remote pilot station emulator. * The RTS simulator of the RPAS vehicle, which embedded the detect and avoid system (i.e., the ASACAS described in this paper) and the ADS-B equipment simulator. * The ATCo working positions simulator, including multiple CWPs to simulate aerodrome control, terminal control, and en-route control operations. * A scenario, environment, and traffic simulator, specifically for intruder (manned or unmanned) aircraft and commercial aircraft normally flying inside the Malta airspace that were considered for the RTS campaign. Additional components of the RTS laboratory environment were:  
* An engineering working station, for data recordings. * The secondary pilot position for safety (on-board) pilot operations such as the hand-over maneuver (the hand-over (H-O) of the RPAS control from the safety pilot to the remote pilot was carried out to simulate in real-time the handover procedure needed in the real world live flight tests for the execution of the flight: the safety pilot is the one onboard the CIRA optionally-piloted aircraft named FLARE (Flying Laboratory for Aeronautical Research) and is in charge of conducting the flight up to the assigned test airspace; once inside the assigned test airspace, the OPA FLARE is remotely controlled by the remote pilot, thus making it an RPAS. Such a transfer of control is executed in the H-O waypoint). To ensure the highest level of the meaningfulness of the results of the simulations, both pilots and controllers operated in their usual operating environments. The RPS, the RTS, and the safety pilot position emulator were located on the CIRA premises in Italy, while the simulated controller working positions were realized on the MATS (Malta Air Traffic Services) premises in Malta. The scenario simulator was shared between the CIRA and MATS premises: MATS fed the real-time simulations with commercial traffic, while CIRA simulated the intruders, both manned and unmanned, that were used for the separation assurance and collision avoidance tests. The remote pilot station was an exact reproduction of the actual remote pilot station used for the CIRA Optionally Piloted Vehicle, as shown in Figure 5[14]. The HMI of the ATCo working position emulator, as used on the MATS premises, is reported in Figure 6[14].