The project to install and test an XT53 turbine engine in this HOK-1 started in February 1956. The first hovering test was on 27 September. Here we get a good view of Kaman's typical inclined twin rotor shafts. Kaman photo. Photo from: Nederlands Instituut voor Militaire Historie
This photo was added on 31 August 2022, and has since been viewed 279 times.