German World War 2 Helicopter
The FL 282 Kolibri also know as Hummingbird was a single seat helicopter designed by german engineer Anton Flettner. The helicopter was equipped with intermeshing rotors, which are slightly angled rotors next to each other rotating in opposite directions. Kolibri had its first flight in 1941 and following year put in to service, used mainly for reconnaissance. Only 24 helicopter were made, although more were in production the manufacturing factory was destroyed and all the remaining helicopter were destroyed in combat at the end of the war.