Faculty of Engineering and Physical Sciences Aeronautical and Astronautical Engineering Doctor of PhilosophyHigh-lift actuation weight estimation using low-cost methods by Benjamin Moss Civil passenger aircraft use high-power actuation systems to deploy high-lift surfaces on the leading and trailing edges of their wings. The mass and size of these systems scales with the expected load the high-lift surfaces are deploy. The problem is that estimated maximum panel loads are not known to a high degree of confidence in the conceptual and preliminary phases of design. The concequence of this in the early phases of the design cycle is that actuation system mass cannot be incorporated to any optimisation loop and traded off against design variables as part of an aerostructural optimisation. This increases uncertainty in the wing weight and the corresponding structural design margins. Ultimately, this uncertainty degrades performance and provides pessimistic estimates of dynamic aeroelastic response.This thesis presents a solution in three parts. First it presents a method for estimating the high-lift actuation system using the aircraft's high-lift geometry. Second, it introduces a novel approach to estimating high-lift panel loads using low cost computational methods suitable for conceptual and preliminary aircraft design. Third, it quantifies the impact of the high-lift actuation system on the dynamic aeroelastic response. vii