Investigation into Schempp-Hirth airbrakes of sailplanes

The present thesis is a study of airbrakes control forces and accelerations generated on the LS8-Standard Class sailplane.

A flight test program was developed and conducted to measure the forces required to operate the Schempp-Hirth airbrakes of the LS 8 sailplane at several airspeeds inside the flight envelope and at several operating speeds. The accelerations produced after this operation were also measured and recorded. Additionally, a computer simulation for the longitudinal motion of the LS 8 was developed and presented.

The flight test program was conducted successfully and representative values for control forces and accelerations generated were recorded. The results from the flight experiments were compared with the current regulations for sailplanes (JAR 22) and, for the case of the accelerations, with the simulation results. For the operating forces, results are available only from the flight experiments. It was found that, in general, the flight test results compared favorably with the flight test data.

Practical procedures are recommended throughout the study.