A design specially built for the testing of several components, like wings and propellers. The machine was loaded with all sorts of measurement instruments. As this was far before the time of automatic registration, these instruments were photographed in flight. At that time glass plate negatives were used for photographing. Interpretation was made on the ground.

 

The machine dates from 1910 (although first described in L'Aérophile 1912) and was continuously modified if needed for the tests. Dorand was an old hand in aeronautics as he was already assigned commander of the Établissement Aérostatique at Chalais-Meudon in 1894.