Reportage of the flight demonstrations Rozenoord airfield near Amsterdam During ‘flight week’, from April 29 to May 8, 1911, flight demonstrations of low-wing and biplanes were held at the Rozenoord airfield near Amsterdam. Airmen and aircraft designers Frits Koolhoven, George Legagneux, and Marcel Hanriot demonstrated their skills on various types of aeroplanes (the Hanriot, the Blériot, and Koolhoven’s ‘Heidevogel’). After landing, they were congratulated by the audience.