Tail Rotor
D/L
I think that you will find that is part of the instrumentation package for the tail rotor. The hub and blades are stuffed with strain guages. I also believe that the floor size of Wildcat is the same area, the difference in overall capacity being a more cluttered cabin due to the crashworthy seats, the increase in actual soldier size (based on demographics the standard is still 1970s) and far more kit being carried.
regards
retard