The development of new technologies – such as rapid prototyping – and the use of materials with improved properties – such as highly resistant extruded polystyrene foam which can be easily and precisely shaped, while conserving its mechanical properties – allow researchers to improve design concepts. This article details the development of a new set of morphing wings for a 15-kg maximum take-off weight Unmanned Aerial Vehicle (UAV) from concept design, to flight tests, including modelling, design optimisation, construction and wind-tunnel tests. A set of comparator-equivalent conventional wings have been used throughout in order to be able to judge any benefits stemming from the adoption of morphing technology. This article shows that the morphing wings provide a controllable aircraft while reducing drag by a factor of 40% compared to the comparator wings with conventional ailerons in a deflected position.