A twin-engine prototype variant of the HH-43B developed in 1962, with a cabin capacity of 8-14 passengers. Several sources list the equipped powerplants of a later version being replaced by PT6 engines.
VTOL type: Helicopter
Lift configuration: Synchropter (x2)
Crew required: 2
Crew seating: Side-by-side
Landing gear: Other
Max Gross Weight (ground): 4763 kg (10501 lb)
Max Range: 628 km (339 nm)