Bell YR-13 Sioux

Bell Helicopter · United States · first flew 1946 · helicopter

The Bell YR-13 was the original US Army designation for the prototype of the Bell Model 47 light helicopter, evaluated by the Army Air Forces in 1946 before entering production as the H-13 Sioux.

Recognition (WEFT)

W — Wings	High-mounted, rotary
E — Engines	1 × piston, fuselage-mounted
F — Fuselage	9.07 m fuselage
T — Tail	Conventional

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Early prototype Sioux with open lattice tail boom and two-blade rotor
Bubble-canopy two-seat cockpit, Franklin piston engine
Predecessor to the Bell H-13 military helicopter series

Open lattice tail boom, large two-blade rotor, bubble canopy, and skid undercarriage are quintessential Bell 47 identifiers; the YR-13 is indistinguishable from early H-13s in silhouette.

Specifications

The Bell YR-13 Sioux has a length of 9.07 m (30 ft).
It has a wingspan of 10.77 m (35 ft).
Its maximum speed is 169 km/h (105 mph).
Typical crew: 1 + 1.

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

Bell submitted the Model 47 to US Army evaluation in 1946, and the initial contract machines were designated YR-13 under the pre-1948 rotary-wing designation system. The design proved reliable and was type-certificated by the CAA in March 1946 as the first commercially certified helicopter in the US. It led directly to the H-13 Sioux series used widely in Korea.

Variants

The YR-13 was the evaluation prototype for the H-13A/B/C series; the broader Bell 47 family spawned dozens of civil and military variants across multiple countries.

Where you'll see it

The YR-13 designation applied only to prototype/evaluation examples; operational service began under H-13 designations with the US Army from 1947.

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