The Helicopter Engineering Research Corporation (HERC) of Pennsylvania was formed by former Piasecki engineers Drago Jovanovich and Frank Kozloski to build the JOV-3 two-seater. It was the predecessor of the McCulloch MC-4, later turned into the Jovair 4. Early helicopter advertising photographs are fascinating stuff. This one is rather odd, as it looks like the pilot is being flagged down to be breathalyzed! Photo from: Vertical Flight Society