During the development of an aerodynamic analysis tool to predict non-linear lift and drag coefficients, research was performed on arbitrary wing configurations focusing on airborne wind energy (AWE) applications. The purpose of this research is to develop and examine the accuracy of computationally fast aerodynamic methods. The non-linear part and maximum value of the lift curve, with the corresponding drag, are of great interest for AWE applied wings, since these y at high angles of attack. By means of a trail and error procedure, a most promising method is found. This research was performed via ASSET at the faculty of Aerospace Engineering and Ampyx Power, following the MSc Sustainable Energy Technology at the faculty of Applied Sciences at the Delft University of Technology. Kite technology has been discovered some 3,000 years ago. Since then, kites have been used to for example send messages, pull carts and perform weather measurements. Nowadays, the most advanced kites are used for sports such as kite surfing. Although higher altitudes can be reached with kites and (AWE) have been developed to extract energy from the wind, the wind energy market is dominated by wind turbines. The efficiency of these turbines is reaching the Betz limit, leaving one option to increase power output, which is increasing the operating altitude. However, structural issues will then appear for a wind turbine tower, where a tethered kite can easily y up to several kilometers altitude. The opportunities of kite power systems have been discovered by scientists, which has resulted in a number of 40 active AWE companies around the world. Ampyx Power is one of these companies, where a tethered rigid sailplane, called the PowerPlane, is used to extract energy from the wind…