Aircraft consume over a billion liters of fuel every day. Therefore, even small increases in efficiency are of great importance in order to save costs. Niklas Wenner (18) and Florian Grunow (16) from Berlin were inspired by the early days of aviation and built a glider model that can be controlled by turning the wings. The advantage: the air gaps of conventional rudders are eliminated. Based on this concept, Wenner and Grunow calculated and designed the required wing shape. In simulations, they showed that air resistance can be reduced in this way. The heart of the wing is an aluminum spar that can be twisted by an electric motor.