04/30/2009. Remarks by Ray Watkins
"The HC-3 is a 4/5 seat general purpose helicopter, developed from the earlier two-seat HC-2 by Jaroslav Šlechta, which
had its first flight in May 1960. Five prototypes were built for testing and demonstration but no production was undertaken.
The pictured second prototype has also been registered as OK-VZA and OK-4, and is presently preserved in Slovakia."