Data for: A twist of the tail in turning maneuvers of a bird-inspired feathered drone

All data used in the article: <b>A twist of the tail in turning maneuvers of a bird-inspired feathered drone</b><b>Abstract</b>: Banked turn is a common flight maneuver observed in birds and aircraft. To initiate the turn, whereas traditional aircraft rely on the wing ailerons, most birds use a variety of asymmetric wing morphing control techniques to roll their bodies and thus redirect the lift vector to the direction of the turn. Nevertheless, when searching for prey, soaring raptors execute steady banked turns without exhibiting observable wing movements apart from tail twisting around the body axis. Despite playing the role as a vertical stabilizer commonly found on traditional aircraft, the reasons why birds twist the tails in banked turn are still not well understood. Here, we develop and use a raptor-inspired feathered drone to find that the proximity of the tail to the wings causes asymmetric wing-induced flows over the twisted tail and thus lift asymmetry, resulting in roll and pitch moments as well as yaw moment to coordinate banked turns. Moreover, twisting the tail induces a nose-up pitch moment that increases the angle of attack of the wings, thereby generating more lift that compensates for losses caused by the banking motion. Flight experiments confirm the effectiveness of tail twist to control not only low-speed steady banked turns but also high-speed sharp turns by means of coordinated tail twist and pitch with asymmetric wing shape morphing. These findings contribute to the understanding of avian flight behaviors that are difficult to study in controlled laboratory settings, and provide effective control strategies for agile drones with morphing aerial surfaces.<br>