The High Lift devices development for small aircrafts has started in a first Clean Sky 2 research phase by selecting several innovative high-lift devices for two different types of SAT aircraft architectures. At the end of the optimization of the aerodynamic and integration design, the different high-lift devices will be classified based upon the benefits of the high lift architectures, and the most suitable design will be selected. From this input, the current proposal will perform Wind Tunnel validation testing of a selected SAT Aircraft High Lift devices System. This validation objective includes the construction of an instrumented model with a segment of wing box including the leading/trailing edge high lift devices, and their aerodynamic characterization by performing tests in a large wind tunnel. An experimental assessment will provide a comparison of the performance and recommendations on the tested High Lift solutions. The research will implement a specific wind tunnel model, designed and manufactured to provide variable positions of flap with respect to the main wing body. Different angles of attack will be tested. Manufactured with the required aerodynamic quality, the model will be installed in the large VKI subsonic wind tunnel and tested at the required Reynolds number. A concept of flap separation control jet blowing system installed at the main wing box trailing edge will also be tested. The tests will be performed with the support specifically designed and manufactured high lift devices models positioning brackets, existing turn table and load balance equipment, and specific interface plates and side walls. Wind tunnel measurements (pressure, force) will be implemented and these measurements will be complemented with PIV measurements for flow field visualization and detailed flow characterization (mean and unsteady behavior). Finally, the performance of the leading & trailing edge high lift solution will be analyzed.