ForewordAs far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.Albert EinsteinSince the early days of aviation, engineers with inventive talents had to overcome tremendous challenges. From building vehicles that can fly in a controllable manner designed and flown by pioneers like Lilienthal, Wright brothers, Sperry in the beginnings, to developing todays modern comfortable and reliable vehicles for daily routine all-weather operations (Airbus, Boeing and others), there were many creative efforts to improve performance (aircraft size, endurance, speed), minimize structural weight, provide necessary thrust, and guarantee safe flight operations. Nowadays all these inventions assure the high mobility of the modern human society in a global world. The aeronautical challenges were drivers for many new technologies and methodologies that are commonly used in other industries today. In the last three decades, the requirements for the design of high-performance flight control systems that enhance automation of flight, initiated a number of ingenious technological developments. Flight control law design is one of the areas where aeronautical engineers are pioneering new technologies.During development (design and test) of flight control laws, engineers rely on mathematical models. Inevitably such models cannot mimic all aspects of a highly complex, physical plant as a modern high-performance jet airplane and its environment (atmosphere, air traffic, etc.) with absolute fidelity. The above quotation from Einstein describes the fundamental difficulty that control engineers are facing, when striving the clearance of flight control laws on basis of mathematical models.However, engineers (named after the Latin word ingenium, meaning innate quality, especially mental power, hence a clever invention) often find solutions even to the most challenging problems. To prove that an aircraft is safe to fly VI Foreword they develop aircraft dynamics models with quantified uncertainties and apply adequate mathematical theories for their analysis. Those models can be used to verify that the control laws operate as specified even when deviations from the nominal conditions occur. In addition, test engineers consider all imaginable test conditions using experience from the past including knowledge about abnormal cases, incidents and accidents. This approach extends the uncertain parameter space with many additional test cases, with special care to investigate the critical ones. The huge amount of possible parameter combinations as well as the presence of model nonlinearities result in an incredibly high number of test cases to be checked for the clearance of flight control laws. The objective of the EC-sponsored project COFCLUO aims at mastering this Herculean task, by applying efficient optimization-based search techniques to discover hidden weaknesses of flight control laws and to determine worst-case parameter combinations to aid possible control law redesigns...