We seen plenty of these in the air in Vietnam.  Was always glad they were there.  In the area I live,  there seem to be choppers in the air all the time,  with several air ambulances,  traffic copters,  and Military Reserve and National Guard units flying in this area regularly.  I don't think I have ever looked up at a helicopter without thinking about the gunships and dustoff  birds of Vietnam.
(Courtesy: Mike Null)