An adaptive wing tip concept was developed to enable controlled wash-in and wash-out throughout the entire flight envelope. The concept is based upon adaptive stiffness structures enables control of the aeroelastic deflections, and also facilitates gust load alleviation. Furthermore, a mathematically based design tool was developed making use of Reduced Order Models (ROMs) of the wing structure and aerodynamics such that an inverse approach can be employed to determine the required sizing of the internal aircraft structure, and also the position and sizing of any adaptive structural components and actuators. The adaptive structural concept and the inverse ROM approach was demonstrated and evaluated on two real-size aircraft test cases.