The design, implementation and validation of avionics and aeronautical systems have become extremely complex tasks due to the increase of functionalities that are deployed in current avionics systems and the need to be able certify them before putting them into production. This book proposes a methodology to enable the rapid prototyping of such a system by considering from the start the certification aspects of the solution produced. This method takes advantage of the model-based design approaches as well as the use of formal methods for the validation of these systems. Furthermore, the use of automatic software code generation tools using models makes it possible to reduce the development phase as well as the final solution testing. This book presents, firstly, an overview of the model-based design approaches such as those used in the field of aeronautical software engineering. Secondly, an original methodology that is perfectly adapted to the field of aeronautical embedded systems is introduced. Finally, the authors illustrate the use of this method using a case study for the design, implementation and testing of a new generation aeronautical router.