## 1 Introduction  
Haptic aids in controlling unmanned aerial vehicles (UAVS) and remotely operated vehicles are gaining interest. The provision of artificial stimulants in the control of UAV flight, remotely as well as in simulation environments, is vital for an increased sense of immersion. Such sensory stimulation is introduced artificially inside the flight simulator/ground control station (GCS) to make the operator experience more natural and realistic than with a visual display alone, due to its limited field of view being insufficient and often unsafe for achieving the flight objectives in flight simulation/teleoperation [1, 2]. In order to incorporate these sensory stimulations, different systems are installed at the GCS, varying in the cost, fidelity requirement, manufacturer capability, and scope of research and development. One of the most important stimulants that should be provided to a UAV operator at the GCS are the forces that are analogous to those acting on the control stick in a manned aircraft flight. Others sensory modalities include visual, vestibular, and auditory stimulations. In this research, the effect of haptic feedback on the operator and his/her behavior in controlling the UAV is explicitly investigated. Aerodynamic loads on control surfaces of the UAV are used to obtain the forces acting on the control stick. These forces are calculated and rendered to help the operator perceive the haptic load that is on the control stick, due to the aircraft's flight state [3]. For example, if an operator performsa turn during a flight, the loads experienced on the control surfaces are transmitted to the control stick inside the cockpit, thereby delivering information about the status of the flight conditions to the operator through the sense of touch. The steady/unsteady loads experienced on the control stick stimulate the haptic sensors of the operator. The hardware for the haptic system consists of an artificial force-loading mechanical device attached to the control stick. This mechanical device controls the magnitude and rate of the force feedback to be transmitted to the control device. It is anticipated in this research that the effect of artificial haptic feedback on the control stick will generate a more immersive experience for the operator and improve his/her situational awareness. More specifically, the goal of this research is to investigate the use of accurate force feedback on the basis of aerodynamic models in improving handling qualities of fixed wing UAVs during flying. Haptic feedback has been used to enhance the information provided by the visual display in various applications. It has been shown that the use of haptic aiding systems improves the handling qualities of UAVs or other remotely operated vehicles [4; 5; 6; 7]. Haptic feedback was provided in the form of attractive and repulsive magnetic forces by defining an artificial force field in obstacle avoidance tasks and exploratory missions. It was demonstrated that the number of collisions and time of mission completion were reduced, due to such haptic cues [8; 9]. Control barrier functions (CBF) have been used to generate force feedback for a quadcopter UAV to aid a safe operation and were evaluated against two conditions, that is, no haptic aids and artificial force fields [10]. Generic haptic aids have been used to investigate the change in pilots' visual and neuromuscular response in target tracking tasks [11]. The utility of haptic feedback as a support system during pilot training was evaluated and shorter training times were observed [12]. Another direction of research is to generate haptic feedback on the basis of pilot intent estimation [13]. Emerging technologies such as robot-assisted surgeries and self-driving vehicles are becoming more effective and risk free by introducing haptic feedback technologies [14; 15].