The insect flight motor serves as a useful model for understanding complex biomechanical systems. The insect body contains numerous evolutionary adaptations that provide them with incredible aerial manoeuvrability and precision. However, we still have a limited understanding of how the muscles, thorax and sensory structures operate together to provide power and fine control during flight. This is perhaps unsurprising as the insect flight motor forms ones of the most intricate mechanical designs found in nature. Small, essentially linear, strains produced by the indirect power muscles are amplified and transformed into the large, nonlinear flapping motion of the wings through subtle deformations of the insect thorax and wing hinge. Our lack of knowledge stems at least in part from the extraordinary difficulty in measuring, or even visualizing, micron-scale muscle movements in vivo at frequencies in excess of 100 Hz. Matters are made more problematic as the many flight muscles are hidden from view behind the thick thoracic shell, which itself forms an integral part of the flight motor. High-speed, time-resolved microtomography provides a method for visualising and measuring the internal and external movements of otherwise inaccessible structures in small organisms1,2. Here I will present the latest research using this technique to investigate multiple aspects of the dipteran flight motor1. Diptera (true flies) form a useful model order as they are united in having a single pair of wings, making many measurements and modelling work simpler, and yet it includes some of the most agile fliers and economically important insect species. This work is providing unprecedented insights into the structure and function of the myriad components that form the insect flight motor, which can then be modelled to answer fundamental questions in biomechanics related muscle function, sensory control and mechanical design. The outcomes from this research will be important for understanding how natural selection has shaped the insect flight motor, while also providing inspiration for engineers interest in building bio-inspired, micro-actuators and air vehicles. Furthermore, high-speed, time-resolved microtomography is a powerful method that can be used to investigate other small-scale, complex biomechanical systems, which undergo repetitive or controllable motions.