Akaflieg Stuttgart fs33  The Akaflieg Stuttgart fs33 "Gavilán" (Spanish: Hawk) is a high-performance two-seater class sailplane designed and built by Akaflieg Stuttgart. Development of the fs33 began in 1990 in response to the redefinition of the FAI two-seater Competition Class in 1989. Additionally, the aircraft should be of high performance, while also possessing pleasant handling characteristics and being viable for regular usage. The design itself was to be based on experiences gained from older prototypes and production aircraft. The project was also supposed to be completed quickly. This led among other things to the use of pre-existing molds to reduce development and construction time. A further focus of the project was safety. To achieve the above mentioned goals, the fuselage molds of the Akaflieg Stuttgart fs31 were reused. Calculations were done based on the fs31's fuselage to determine the optimal geometry and mass for the vertical fin and tailplane, which led to the use of the fin of a Schempp-Hirth Nimbus 3D and tailplane of a Nimbus 4D, though slightly modified to fit the fuselage. Furthermore, most of the control rods in the cockpit, the wheel brakes, and the rear lift pin tube were taken over from the Schleicher ASH 25. To create the wings, the wing molds of the Akaflieg Stuttgart fs32 were taken and extended inwards by 2,5 meters. Unlike in the fs32, the fs33 doesn't possess slotted flaps due to their complexity, instead using regular flaperons. Due to the lower than expected wing area gain, lightweight construction became an important factor to keep the design's wing loading within acceptable levels. The fs33 is a two-seater glider with a mid-mounted triple-trapezoidal wing. It has a wingspan of 20 meters and its wings are each equipped with three flaperons along the entire span and optional winglets. Operation of the flaperons is controlled by a mixer located at the wing root and the wings' control connections with the fuselage are automatic. The aircraft is almost entirely made out of carbon fiber composites, with the cockpit region being instead made out of a carbon-kevlar hybrid. Carbon fiber rovings were used to build the wing spars, while the skin was made of carbon fiber scrims () as a weight saving measure.