Keywords: Oemichen2.jpg Étienne Oehmichen Helicopter No 2 1923-1924 On May 4 1924 it was the first helicopter to fly on the distance of one kilometer 0 6 mile in a closed-circuit landing at his starting point L'hélicoptère N°2 d'Étienne Œhmichen 1923-1924 Il est le premier à réaliser un vol d'1 km en circuit fermé le 24 mai 1924 1924 Public domain author PD-old Étienne Œhmichen Early aircraft Quadrotors |