Flight simulators have in some form been used in over a century. Already in the first decade after the Wright brothers did their first flight there was a great need of pilot training which led to the building of the first simulators. Over the years as technology developed, the simulators evolved from simple mechanical rigs to electro-mechanical full system simulators. Today there is a wide range of flight training devices, from relatively simple part task trainers and cockpit procedures trainers to full flight simulators that are capable of moving in all six degrees of freedom (6-DoF).
With the introduction of computers aircraft designers got the possibility to perform more advanced calculations, and to simulate the aircraft response. The introduction of digital flight control systems further increased the need for simulations and a model based working approach. The most important reasons are to increase the quality and safety of the aircraft while decreasing cost and time of development.
The possible combinations of aircraft configurations, flight states and manoeuvres are infinite and to validate the function sufficiently by flight tests would be too time-consuming. Doing that there would still be tests left that are too dangerous to perform either because of a difficult flight state or manoeuvre, too hard environmental condition like wind, or the testing of a faulty aircraft.
Reusability is a key feature
A model-based design approach helps in the design of the control laws, the verification of the function and the validation of the usability. By developing the models with reusability in mind they can be used in different types of simulators.
Finding problems early
Model based design facilitates shorter design loops with a lot of testing in the early phases of the control system design. It minimizes expensive testing in H/W-rigs and aircrafts and flight tests is mainly used for model feedback and validation. Most of the requirements can also be closed in simulators leaving only a few for flight test where pilot-in-the-loop and physical awareness is needed.
Model based design have proved to deliver a better and safer product. The customer can be included in the early phases of the design and costly design mistakes can be eliminated. The models that are developed during the design phase of the aircraft can be used in other applications and products like pilot and mission training.