The CH-34 Choctaw cargo and light tactical transport helicopter (Sikorsky Model S-58) was a lengthened and more powerful version of the H-19 Chickasaw cargo helicopter. The CH-34 could carry up to 16 troops or eight litters and a medic in the MedEvac role. The CH-34 entered service with the U.S. Army in April 1955 and rapidly became the principal Army transport helicopter, with 437 CH-34A/B/C models in inventory by 1970. ARVN acquired the CH-34 but it was not used by the U.S. Army in Vietnam. The Marine Corps version (UH-34D Seahorse or HUS-1) was the primary Marine utility/assault helicopter used in Vietnam and by the CIA Air America in Laos.
The U.S. Navy procured the Sikorsky Model S-58 as the anti-submarine HSS-1 Seabat. It was also licensed and manufactured in Great Britain (with a turbine engine) where it was named the Wessex.
The CH-34 Choctaw had a single four-bladed main rotor and a four-bladed metal tail rotor. Although it was very robust and generally liked and respected by its crews, there were design flaws exposed by combat experience in Vietnam. The high cockpit made it an obvious target. The drive shaft created a partition that made it difficult for crew chiefs to come to the aid of injured cockpit crew. The H-34's magnesium skin resulted in very intense fires, and contributed to significant corrosion problems. The airframe was also too weak to support most of the weapons that allowed the UH-1 Huey to become an effective ad-hoc gunship.
Sikorsky CH-34 Choctaw Specifications and Performance
46 ft. 9 in.
15 ft. 11 in.
1425 hp Curtis-Wright R-1820-84C (radial pistons)
Sikorsky CH-34 Choctaw helicopter.
CH-34 Choctaw helicopter, Fitzsimons Army Hospital, Aurora, CO, 13 September 1956.
Technicians work on a Marine HUS-1 / CH-34 Seahorse helicopter on the beach at Cua Viet, Vietnam, 1 October 1966.
Marine HUS-1 / CH-34 Seahorse helicopter on the runway at Dong Ha, Vietnam, 1 July 1967.
An air-to-air left front view of a Marine HUS-1 / CH-34 Seahorse helicopter over Cua Viet, Vietnam, 1967.