Bell H-13 Sioux

The H-13 Sioux was a two-bladed, single engine, light helicopter built by Bell Helicopter . Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT.2.

Development

In 1947, the United States Army Air Forces (later United States Air Force ) ordered the improved Bell Model 47A . Most were designated ''YR-13'' and three winterized versions were designated ''YR-13A''. The United States Army first ordered Bell 47s in 1948 under the designation ''H-13''. These would later receive the name "Sioux".

Initially, the United States Navy procured several Bell 47s, designated ''HTL-1'', between 1947 and 1958. The United States Coast Guard evaluated this model, and procured two HTL-1s for multi-mission support in the New York Harbor. The most common US Navy version of the 47 was designated the ''HTL-4'', and dispenses with the fabric covering on the tail boom. The US Coast Guard procured three ''HTL-5''s in 1952 (similar to the HTL-4 but powered by a Franklin O-335-5 engine) and used these until 1960. The Coast Guard procured two of Bell's Model 47G and designated them ''HUL-1G'' in 1959.

The H-13 was used as observation helicopter early in the Vietnam War , before being replaced by the OH-6 Cayuse .

The Bell 47 was ordered by the British Army as the Sioux to meet specification H.240, with license production by Westland Helicopters . In order to comply with the terms of its licence agreement with Sikorsky Aircraft , which prevented it building a US competitors aircraft, Westland licenced the Model 47 from Agusta , who had purchased a license from Bell. the first contract was for 200 helicopters. The first 50 helicopters of the contract were built by Agusta at Gallerate in Italy followed by 150 built by Westland at Yeovil. The first Westland Sioux made its maiden flight on 9 March 1965.

Design

The Sioux is a three seat observation and basic training helicopter . The Bell 47G design was introduced in 1953. This design can be recognized by the full bubble canopy , exposed welded-tube tail boom, saddle fuel tank s, and skid landing gear.

The H-13 and its military variants were often equipped with medical evacuation panniers, one to each skid, with an acrylic glass shield to protect the patient from wind.

A single 260 hp Lycoming VO-435 piston engine was fitted to the 47G variant. The fuel were fed from two high level mounted external tanks. A two bladed single rotor with short inertial stabilising minor blades was used on the Sioux.

Variants

Military

YR-13

/HTL-1: 28 Bell 47A helicopters procured by the United States Army Air Forces for evaluation. The YR-13 was powered by a 175 hp (130 kW) Franklin O-335-1 piston engine. 10 of the aircraft were evaluated by the U.S. Navy as trainers.

YR-13A

3 YR-13 aircraft winterized for cold-weather testing in Alaska. Redesignated YH-13A in 1948.

HTL-2

US Navy equivalent of the commercial Model 47D. 12 built.

HTL-3

US Navy equivalent of the commercial Model 47E, powered by a 200 hp (149 kW ) Franklin 6V4-200-C32 engine. Nine built.

H-13B

65 aircraft ordered in 1948 by the U.S. Army. All Army versions were later named Sioux.

YH-13C

One H-13B used as engineering testbed. Fitted with skid undercarriage and open, uncovered tailboom.

H-13C

16 H-13B aircraft converted to carry external stretchers in 1952, with skid landing gear and open tail boom of YH-13C.

H-13D

Army two-seat version based on commercial model 47D-1, with skid landing gear, stretcher carriers, and Franklin O-335-5 engine. 87 built.

OH-13E

H-13D configuration with three-seat aircraft with dual controls. 490 built.

XH-13F

/Bell 201 : Modified Bell 47G powered by a Continental XT51-T-3 (Turbomeca Artouste ) turboshaft. The first Bell helicopter powered by a turbine engine.

OH-13G

Three-seater based on commercial model 47-G. Introduced a small elevator on the tailboom. 265 delivered to US Army.

OH-13H

/UH-13H: Based on 47G-2. Equipped with a 250 hp (186 kW) Lycoming VO-435 engine. At least 453 acquired by US Army. UH-13Hs were used by the U.S. Air Force.

UH-13J

Two Bell 47J-1 Rangers acquired by the U.S. Air Force for VIP transport of the U.S. President. Originally designated as H-13J.

OH-13K

Two converted H-13Hs with a larger diameter rotor and a 225 hp (168 kW) Franklin 6VS-335 engine for test evaluation.

TH-13L

Originally designated as the Navy ''HTL-4''.

HTL-5

Utilized a Lycoming O-335-5 engine.

TH-13M

Incorporated a small movable elevator. Originally designated as the Navy ''HTL-6''.

HH-13Q

Originally the ''HUL-1G'', it was used by the U.S. Coast Guard for search and rescue.

UH-13R

Powered by an Allison YT63-A-3 turbposhaft engine. Original US Navy designation ''HUL-1M''.

OH-13S

Three-seat observation helicopter based on 47G-3B to replace the OH-13H. 265 received by US Army.

TH-13T

Two-seat instrument trainer for the U.S. Army based on the 47G-3B-1, powered by 270 hp (201 kW) Lycoming TVO-435-D1B. 411 purchased.

Sioux AH

.1General purpose helicopter for the British Army, 50 built by Agusta (Agusta-Bell 47G-3B1) and 250 built by Westland (Westland-Augusta-Bell 47G-3B1).

Sioux HT

.2Training helicopter for the Royal Air Force , 15 built by Westland.

Operators

* Argentine Navy - Argentine Naval Aviation

* Argentine Naval Prefecture

65 Bell 47 Sioux helicopters were in service with both the Australian Army and RAAF from 1960 to 1977.

* Australian Army - Australian Army Aviation

** No. 16 Army Light Aircraft Squadron

** No. 183 Squadron

** No. 162 Flight

** No. 171 Flight

** No. 182 Flight

* Royal Australian Air Force

** No. 16 Air Observation Post Flight RAAF

* Austrian Air Force

* Brazilian Air Force

* Royal Canadian Navy

* Royal Danish Air Force

** (722th squadron ) in cooperation with Geus

* German Army

* Luftwaffe

* Icelandic Coast Guard

* Israeli Air Force

* Jamaica Defence Force

* Royal New Zealand Air Force

** No. 3 Squadron RNZAF

* Pakistan Air Force

* Peruvian Air Force

* Peruvian Naval Aviation

* Peruvian Army Aviation

* Philippine Air Force

* Vietnam Air Force

SWE

THA

TUR

UK

* British Army Army Air Corps

* Royal Air Force

** Central Flying School

* Royal Marines

** 3 Commando Brigade

USA

* United States Army

* United States Air Force

* United States Navy

* United States Marine Corps

* United States Coast Guard

URU

VEN

YUG

ZAI

ZAM

Survivors

* The Pueblo Weisbrod Aircraft Museum , Pueblo, Colorado has a restored H-13G with a "M*A*S*H" look.

* The Museum of Modern Art (MoMA) in New York City has a [http://www.moma.org/collection/browse_results.php?object_id=2234 Bell 47D1] on permanent display.

* Castle Air Museum in Atwater, CA has a Bell H-13 with the M*A*S*H paint scheme in their "Hidden aircraft collection".

* Adventure Aviation in Tauranga, New Zealand uses a Bell 47G in a "M*A*S*H" paint scheme for tourist scenic flights.

* Bell 47G-2 AS7201 of the Armed Forces of Malta was formally retired on May 30, 2008 and donated to the [http://www.maltaaviationmuseum.com/ Malta Aviation Museum] at Ta'Qali .

* The United States Army Medical Museum located on base at Fort Sam Houston, in San Antonio Texas, has a Bell 47 on display with other helicopters.

* Wings of Freedom Aviation Museum located in Horsham, PA has an H-13 on display.

*H-13 on display at the War Memorial of Korea , Seoul , Republic of Korea

Specifications (Sioux AH.1)

Popular culture

The Bell 47 appeared, and played key roles, in film and television productions. It has been associated with both the ''M*A*S*H '' film, and the ''M*A*S*H '' television series, and the ''Whirlybirds '' TV series (1957–1959).