The contest was open on July 18, 1930, at Berlin-Staaken airfield. It consisted of two parts: a circuit over Europe and technical trials. Since one of the aims of the Challenge was to generate a progress in aircraft designing, it was not only pilots' competition, but technical trials also included a construction evaluation, to build more advanced and reliable touring planes. All planes flew with two-men crews, pilot and passenger or mechanic (apart from the Swiss Charles Kolp, who took two passengers, including one woman, into his Klemm VL.25).