The story
The company was founded in 1955 as a commercial successor of the Stichting voor de Ontwikkeling en Bouw van een Experimenteel Hefschroefvliegtuig (SOBEH - the Foundation for Development and Manufacturing of an Experimental Helicopter). From 1951 on, SOBEH developed and built two helicopters, the H-1 (1954) and H-2 (1955). After having met its goal of developing a helicopter, SOBEH ceased activities. Further development and serial production were granted to the newly formed NHI. This was a joint venture between aircraft manufacturer Aviolanda and truck company Kromhout. NHI quickly came forward with an improved design, called the H-3 Kolibrie (Hummingbird). This helicopter was powered by ramjets at the ends of the blades and made its first flight in May 1956. The Certificate of Airworthiness, based on U.S. requirements for rotorcraft, was issued in March 1958.
From Wikipedia’s article on Nederlandse Helikopter Industrie, shared under CC BY-SA 4.0.3
