Bell H-13 Sioux
Technical Information

Background
Built by Bell. On December 8, 1945 the Bell 47 prototype made a first flight. In 1947, the United States Army Air Forces (later the United States Air Force) ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. In 1948, the United States Army first ordered Bell 47s designated H-13 Sioux. Manufactured by Westland Aircraft under license for the British and Commonwealth as Sioux AH.1 and HT.2.

Korean War
During the Korean War, the H-13 was one of the principal helicopters used by the U.S. Army. Used in a wide variety of roles including observation, reconnaissance, and medivac.

Vietnam War
Used as an observation helicopter early in the Vietnam War, before being replaced in 1966 by the Hughes OH-6 Cayuse.

Production
A total of roughly 2,407 were built.

Technical Details
Crew  1-3 (pilot, passengers)
Engines  1 × Lycoming TVO-435-A1A six-cylinder, horizontally opposed piston, 260 hp (190 kW)
Length  31' 7" (9.63m)
Height  9' 8" (2.95 m)
Maximum Speed  105 mph (169 km/h, 91 kn)
Range  273 mi (439 km, 237 nmi)
Armament  None, twin .30 cal machine guns
Capacity  Two strechers mounted externally