User:Colin Douglas Howell/Light piston helicopters, 2-3 seats

Two-seat and three-seat light utility helicopters powered by a single piston engine. The very first mass-produced helicopter, the Sikorsky R-4, was of this type, as are such notably common helicopters as the Bell 47, Hiller UH-12, Hughes/Schweizer 269/300, and Robinson R22. Helicopters like this are often seen in police patrol or traffic-reporting duties, as well as being used for training new helicopter pilots. In military service, they have been used for observation, liaison, medevac, search and rescue, and training work.

These helicopters usually have an engine of a "flat" (horizontally-opposed) type, a flat-six in earlier models and a flat-four in later ones, but the British-made Saunders-Roe Skeeter used an inverted straight-four, and both the Sikorsky R-4 of the 1940s and the Soviet-built Kamov Ka-15 used radial engines. The engine is almost always air-cooled; the Ukrainian-made Aerokopter AK1-3 Sanka is an unusual exception in having a Subaru liquid-cooled automotive engine.

Over time there has been a gradual trend for these helicopters to become lighter, with smaller engines, most markedly with the transition from six-cylinder to four-cylinder engines starting in the later 1950s.

Sikorsky R-4 / HNS-1 / Hoverfly edit

Sikorsky R-4B at the National Museum of the United States Air Force

American two-seat light utility helicopter. The first mass-produced helicopter and the first to be used by the U.S. military, including the U.S. Army Air Forces, U.S. Navy, and U.S. Coast Guard, as well as the Royal Air Force and Royal Navy.

Produced: 1942–1944
Number built: 131
Capacity: 2
Gross weight: 2,540 lb (1,152 kg)
Engine: Warner R-550-3 Super Scarab 7-cylinder radial, 200 hp (150 kW)
Maximum speed: 75 mph (121 km/h, 65 kn)
Range: 130 mi (210 km, 110 nmi)
Service ceiling: 8,000 ft (2,400 m)

Sikorsky R-6 / HOS-1 / Hoverfly II / S-49 edit

Sikorsky R-6A at the National Museum of the United States Air Force

American two-seat light utility helicopter. Used by the U.S. Army Air Forces, U.S. Navy, U.S. Coast Guard, Royal Air Force, and Royal Navy.

Introduced: 1945
Number built: 225
Capacity: 2
Gross weight: 2,600 lb (1,179 kg)
Engine: Franklin O-405-9 (6ACV-403) flat-6, 240 hp (180 kW)
Maximum speed: 100 mph (160 km/h, 87 kn)
Service ceiling: 10,000 ft (3,000 m)

Bell 47 / H-13 Sioux edit

Danish civil Bell 47G-5

American two or three-seat light utility helicopter. Used by many civil and military operators, including the U.S. military. One of the most-produced helicopters in history. Possibly most famous for its prominent role in the U.S. television series M*A*S*H, set during the Korean War.

Produced: 1946–1974
Number built: 5,600
Capacity: 3
Max takeoff weight: 2,950 lb (1,338 kg)
Engine: Lycoming TVO-435-F1A flat-6, 280 hp (210 kW)
Maximum speed: 105 mph (169 km/h, 91 kn)
Range: 246 mi (396 km, 214 nmi)
Service ceiling: 16,100 ft (4,900 m)

Hiller OH-23 Raven / UH-12 edit

Hiller OH-23G Raven of the U.S. Army

American two or three-seat light utility and observation helicopter. Used by civil and military operators such as the U.S. Army.

Introduced: 1948
Number built: 1,836+
Capacity: 3
Max takeoff weight: 2,700 lb (1,225 kg)
Engine: Lycoming VO-435-23B flat-6, 250 hp (190 kW)
Maximum speed: 95 mph (153 km/h, 83 kn)
Range: 197 mi (317 km, 171 nmi)
Service ceiling: 13,200 ft (4,000 m)

Saunders-Roe Skeeter edit

Saunders-Roe Skeeter AOP.12 of the RAF Central Flying School in 1962

British two-seat light utility helicopter, used by the British and West German militaries.

Introduced: 1956
Number built: ~80
Capacity: 2
Max takeoff weight: 2,300 lb (1,043 kg)
Engine: de Havilland Gipsy Major 215 inverted straight-4, 215 hp (160 kW)
Maximum speed: 109 mph (175 km/h, 95 kn)
Range: 260 mi (420 km, 230 nmi) at 86 mph (138 km/h, 75 kn)
Service ceiling: 12,800 ft (3,900 m)

Kamov Ka-15 "Hen" edit

Kamov Ka-15 in Aeroflot markings, with rotors stripped, at the Russian Air Force Museum

Soviet two-seat light utility helicopter used by the Soviet navy and Aeroflot. Has the typical Kamov layout of twin coaxial counter-rotating main rotors, with twin tail fins and rudders instead of a tail rotor.

Introduced: 1955
Number built: 375
Capacity: 2
Max takeoff weight: 3,109 lb (1,410 kg)
Engine: Ivchenko AI-14V 9-cylinder radial, 250 hp (190 kW)
Maximum speed: 93 mph (150 km/h, 81 kn)
Range: 240 mi (390 km, 210 nmi)
Service ceiling: 9,800 ft (3,000 m)

Brantly B-2 edit

British civil Brantly B-2B

American two-seat light utility helicopter used by civil operators.

Introduced: 1958
Number built: 334 (as of 2011)
Capacity: 2
Max takeoff weight: 1,670 lb (757 kg)
Engine: Lycoming IVO-360-A1A flat-4, 180 hp (130 kW)
Maximum speed: 100 mph (160 km/h, 87 kn) at sea level
Range: 250 mi (400 km, 220 nmi)
Service ceiling: 10,800 ft (3,300 m)

Hughes TH-55 Osage / 269 / 300 / Schweizer 300 edit

Dutch civil Schweizer 300C

American two to three-seat light utility helicopter. Used by civil and military operators such as the U.S. Army. Produced since 1983 by Schweizer (under Sikorsky for a limited period).

Introduced: 1961
Number built: 2,800+
Capacity: 2-3
Max takeoff weight: 2,050 lb (930 kg)
Engine: Textron Lycoming HIO-360-D1A flat-4, 190 hp (140 kW)
Maximum speed: 109 mph (176 km/h, 95 kn)
Range: 224 mi (361 km, 195 nmi)