The Bell 47, a single-rotor single-engine light helicopter, was manufactured by Bell Helicopter.
It originated from the third Bell 30 prototype, which was the company’s first helicopter designed by Arthur M. Young.
Over 5,600 Bell 47s were produced, including those under license by Agusta in Italy, Kawasaki Heavy Industries in Japan, and Westland Aircraft in the United Kingdom.
The Bell 47J Ranger is a modified version featuring a fully enclosed cabin and tail boom.
Early versions displayed a range of looks, featuring either open cockpits or sheet metal cabins, fabric-covered or open structures, and some equipped with four-wheel landing gear.
However, later models like the D and Korean War H-13D and E types adopted a more practical design.
The 47G, which became the most prevalent model after its introduction in 1953, is easily identifiable by its distinctive “soap bubble” canopy, exposed welded-tube tail boom, saddle fuel tanks, and skid landing gear.
The Bell H-13 Sioux is the military version of the Bell 47 these were manufactured by Westland Aircraft
under license for the British military as the Sioux AH.1 and HT.2.
Variants
YR-13/HTL-1
The United States Army Air Forces procured 28 Bell 47A helicopters for evaluation.
The YR-13 model was equipped with a 175 hp (130 kW) Franklin O-335-1 piston engine.
The U.S. Navy evaluated 10 of these aircraft as trainers.
YR-13A
Three YR-13 aircraft were winterized for cold-weather testing in Alaska and were redesignated as YH-13A in 1948.
HTL-2
The US Navy’s counterpart to the commercial Model 47D is the HTL-2, with a total of 12 units constructed.
HTL-3
The HTL-3 is the US Navy’s equivalent of the commercial Model 47E, equipped with a 200 hp (149 kW) Franklin 6V4-200-C32 engine.
A total of nine were constructed.
H-13B
In 1948, the U.S. Army placed an order for 65 aircraft.
All versions delivered to the Army were subsequently designated as Sioux.
YH-13C
An H-13B was utilized as an engineering test bed, equipped with a skid undercarriage and an open, uncovered tail boom.
H-13C
In 1952, sixteen H-13B aircraft were modified to transport external stretchers, equipped with skid landing
gear and the open tail boom characteristic of the YH-13C.
H-13D
The Army’s two-seat variant, modelled after the commercial 47D-1, featured skid landing gear, stretcher
carriers, and was powered by a Franklin O-335-5 engine.
A total of 87 units were constructed.
OH-13E
The H-13D is a configuration featuring a three-seat aircraft with dual controls, with a total of 490 units
constructed.
XH-13F/Bell 201
The modified Bell 47G, equipped with a Continental XT51-T-3 (Turbomeca Artouste) turboshaft, was the
first Bell helicopter to be powered by a turbine engine.
OH-13G
The three-seater, derived from the commercial Model 47-G, featured a small elevator on the tail boom.
A total of 265 units were delivered to the US Army.
OH-13H/UH-13H
The model is based on the 47G-2, equipped with a 250 hp (186 kW) Lycoming VO-435 engine.
The US Army acquired at least 453 units.
Additionally, the UH-13Hs were utilized by the U.S. Air Force.
UH-13J
The U.S. Air Force acquired two Bell 47J-1 Rangers for the VIP transport of the U.S. President, originally
designated as H-13J.
OH-13K
Two H-13H helicopters were modified with a larger diameter rotor and equipped with a 225 hp (168 kW)
Franklin 6VS-335 engine for testing and evaluation purposes.
TH-13L
Initially designated as the Navy HTL-4.
HTL-5
The Lycoming O-335-5 engine was employed.
TH-13M
Integrated a compact, mobile elevator.
Initially known as the Navy HTL-6.
HH-13Q
Initially designated as the HUL-1G, this model was employed by the U.S. Coast Guard primarily for search
and rescue operations.
UH-13R
Equipped with an Allison YT63-A-3 turboshaft engine and originally designated as HUL-1M by the US
Navy.
OH-13S
The OH-13S, a three-seat observation helicopter derived from the 47G-3B, was acquired to succeed the OH-13H.
The US Army received a total of 265 units.
TH-13T
The U.S. Army acquired a two-seat instrument trainer based on the 47G-3B-1, equipped with a 270 hp
(201 kW) Lycoming TVO-435-D1B engine.
A total of 411 units were purchased.
Sioux AH.1
The British Army utilized the general-purpose helicopter, with 50 units constructed by Agusta (Agusta
Bell 47G-3B1) and 250 by Westland (Westland-Agusta-Bell 47G-3B1).
Additionally, a limited quantity was employed by the 3 Commando Brigade Air Squadron of the Royal Marines.
Sioux HT.2
The Royal Air Force utilized a training helicopter, with 15 units constructed by Westland.
Specifications
Crew
1 or 2
Capacity
3 passengers
(1,057 lb (479 kg) payload)
Length
31 ft 7 in (9.63 m)
Height
9 ft 3 in (2.82 m)
Empty weight
1,893 lb (859 kg)
Max take-off weight
2,950 lb (1,338 kg)
Powerplant
1 × Lycoming TVO-435-F1A, a six-cylinder, vertically mounted, horizontally opposed, air-cooled piston engine with 280 hp (210 kW).
Main rotor diameter
37 ft 2 in (11.33 m)
Main rotor area
1,085 sq ft (100.8 m2)
Performance
Maximum speed
91 kn (105 mph, 169 km/h)
Cruise speed
73 kn (84 mph, 135 km/h)
Range
214 nmi (246 mi, 396 km)
Rate of climb
860 ft/min (4.4 m/s).
Sources
bellflight.com
Airmobile: The Helicopter War in Vietnam-J Mesko.
Vietnam: The War in the Air-J Francillon.
H-13 Sioux, Mini in Action No.6-Squadron Signal Publications.
