The HO5S-1 served as the Marine Corps’ primary medical evacuation helicopter in the final year of the Korean War. Able to carry wounded on internally-mounted litters with an attendant, it was an improvement over other light utility helicopters that required the wounded to ride outside of the fuselage while exposed to harsh conditions. The HO5S-1 featured an opening front bubble for easy access, a rear-mounted (and severely underpowered) engine configured to maximize internal carrying capacity and offset rotor blade flapping hinges to improve control and stability, which made it ideal for night flying.
In July 1952, this HO5S-1, one of only a handful of surviving Korean War helicopters, was one of the first examples delivered to Observation Squadron VMO-6, which performed the majority of helicopter-borne medical evacuations for wounded Marines in Korea, evacuating over 5,000 seriously wounded personnel. Postwar, it served with Orlando Helicopter Airways as an air taxi and crop sprayer, as well as a platform to test an all-electric drive system.
Rotor diameter:10.1 m (33 ft)
Length:9.1 m (29 ft 9 in)
Height:2.6 m (8 ft 7 in)
Weight, empty:802 kg (1,768 lb)
Weight, gross:1,225 kg (2,700 lb)
Top speed:185 km/h (115 mph)
Engine:Aircooled Motors, O-425-1, 245 hp
Manufacturer:Sikorsky Aircraft Div., United Aircraft Corp., Bridgeport, Conn., 1952