First flight of the NHI H-3 Kolibri
Saturday, December 31, 1955
The helicopter was an all Dutch venture building on the patents held by Jan M. Drees.
Note: The exact day in December is unknown at present.
Source: "Helicopters & Autogiros of the World", Paul Lambermount with Anthony Pirie, Cassell &Company Ltd., 1958, Page 182