Given the question: Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Adaridi AD 3 - Adaridi AD 3 was a wooden aircraft designed by the Russian engineer Boris Adaridin who lived in Finland. It was a high wing aircraft with a low-powered engine. In 1923 the Finnish Air Force ordered one Adaridi aircraft. The aircraft was not given any official designation code. The maiden flight was on April 17 1924. The German ace Leutnant Emil Thuy (32 victories in World War I) described the aircraft as having mediocre flying qualities and that the 12 hp engine was inadequate.
The answer is:
Mean Of Transportation