Fin extension
Movable stabilator a la Blackhawk (is this the origin of the "heavyweight tailplane")?
Nav lights therefore behind cockpit doors, rather than on tail
Lower strake
Landing/search lights in nose fairing
Pitot above cockpit door
Lack of lower transparency in nose
Lack of inspection panels on upper deck - does the front fairing slide forwards?
Extra fairing/scoop below main rotor
Rotor head / blade attachment design
Bifilar?
Non-swept rotor blade tips
No floats
Seat design
Smaller, younger test pilot.
