The project Modern Control methods has been carried out as a part of the national "Flygteknik 06-08" program (Aeronautical Research and Technology Development) with the aim of facilitating the transition in industry to nonlinear methods for flight control system (FCS) design. The main object has been to investigate methods that can reduce the design cycle time, so that a new FCS can be designed quickly in each iteration or update of the design process, and methods that can handle the hard nonlinearities (limits) of actuators. Both these aspects represent limits to the current design practice. It is shown that each of these limits can be handled separately with recently developed methods, but more research is needed to find methods that can handle both problems simultaneously.