To obtain a quantitative measure of predicted FTFC system performance in degraded modes, specifications need to be defined to assess proper functioning under realistic operational flight conditions. The goal of the benchmark specifications modelling, as described in this chapter, is to create a set of assessment criteria in order to evaluate the quality of the performance of fault detection and identification (FDI) and reconfigurable control algorithms. The lay-out of this chapter is as follows. First, the specifications modelling process is introduced by discussing the benchmark scenario. Subsequently, the general evaluation criteria will be considered by defining two classes of test manoeuvres. Thereafter, focus is placed on the test manoeuvres for FTFC qualification, which is the major topic of this chapter. After the discussion on how the assessment quantities of interest can be divided into two categories, four qualification test manoeuvres are discussed in depth. These include straight flight, right turn and localizer intercept, glideslope intercept and final approach with sidestep. Finally, a summary of the specified assessment quantities is given for the different FTFC qualification test manoeuvres. These criteria have also been published in Ref. [3]. © 2010 Springer-Verlag Berlin Heidelberg.