Flight loads assessment of failure cases with pilot models

摘要

Flight control failure cases require careful consideration and analysis from a control law perspective as well as an airframe loads viewpoint and moreover, possible pilot control actions also need to be considered. Here, a simulation framework and its development methodology are presented that allows manual control action to be included within the flight loads process to study failure scenarios. This enables the analysis of interactions between manual control action and flight control schemes (that include loads control) in the early design stages. The algorithmic modified optimal control pilot model has been implemented for assessing a soft oscillatory aileron failure on a conventional large transport aircraft. The pilot model was parameterised using a series of simulation trials before being integrated within the aeroservoelastic simulation framework used to obtain quantities such as bending moment and torsion for the wing and tailplane. Pilot-model-in-the-loop simulations of the worst case aileron failure frequency show that manual pitch compensation leads to tailplane loads that significantly exceed the calculated envelope loads. Such an outcome in effect demonstrates the utility of applying pilot models within flight loads processes.