Steve,
I am late to this thread, sorry.
I know that the FAA does officially pass judgement on what you ask, for every type. As a certification rule, the FAA requires that any aircraft above 12,500 pounds must have a specific endorsement for you to be PIC. For aircraft below that weight, a board meets as part of the official type certificate process. This board is made up of FAA operational check pilots who judge the flight skill needed to decide if a specific type checkout should be required.
The FAA does not require specific signoffs for each type helicopter, unless that pilot and helo are used in Part 135 operations.