This thesis studies possible solutions regarding the increase of stall, cruise and critical landing and takeoff operation performance of a STOL light aircraft thanks to passive high lift or flow control devices. Firstly, the problem that creates the need for this thesis is discussed as to organise the goals and aim of it. Then, the state of the art is studied, and possible solutions are considered as candidates which are analysed furthermore and compared. A simulation phase ensues after a learning process of the simulation tools that should be used. The best solution candidates are then compared, and an implementation study follows with the purpose of analysing whether they will be feasible or not. This project is part of a joint effort comprising many other projects from the e-project initiative to design a fully electric STOL airplane for air urban mobility operations. Consequently, constant information sharing was performed, and meetings held with those involved with it.