Hughes are on to a winner with NOTAR. Instead of a noisy tail rotor, air is drawn from the modified engine and pumped down the tail boom to emerge through a slot in one side of the end. By simply flying as normal, the pilot's inputs through the rudder pedals result in more or less air coming out the vent, resulting in the boom moving to left or right.
The main advantage is in the noise reduction achieved over a conventional tail rotor, making the NOTAR very attractive for those agencies who have to fly regularly in residential areas.
As to models, I'll leave that answer to come from one of the more knowledgeable readers of these pages! Hope this info. is of value to you.