User:Colin Douglas Howell/Large piston helicopters
Single-engined large piston helicopters
[edit]Large helicopters powered by a single piston engine. These were usually transports, seating around 12 to 20 passengers (plus a crew of two or three), with a maximum takeoff weight in the range of 13,000 to 17,000 pounds and with engine power of 1,400 to 1,700 horsepower. The engine was always a large air-cooled radial. Helicopters of this sort were also used for other tasks, such as search and rescue, anti-submarine warfare, and ground attack. The most common helicopters in this class were the Mil Mi-4 and the Sikorsky H-34.
(The unusually heavy and powerful tandem-rotor Bell HSL, with a maximum takeoff weight of 26,500 pounds and an engine of 2,100 horsepower, yet dedicated to anti-submarine warfare rather than transport, was rather an outlier in this category and had a very short career.)
These large helicopters first appeared in the early 1950s. Although large helicopters began to use turboshafts rather than piston engines in the later 1950s, the piston-engined Sikorsky H-34 remained in production through the 1960s, and its Soviet counterpart, the Mil Mi-4, through the 1970s.
American 15-to-20-passenger tandem-rotor transport helicopter, used by the U.S. Air Force and Army, among other military and civil operators. Sometimes nicknamed "Flying Banana", a nickname it borrowed from its predecessor, the Piasecki HRP.
- Produced: 1952–1959
- Number built: over 700
- Capacity: 20 passengers (plus 3 crew)
- Gross weight: 15,200 lb (6,895 kg)
- Engine: Wright R-1820-103 Cyclone 9 9-cylinder radial, 1,425 hp (1,063 kW)
- Maximum speed: 127 mph (204 km/h, 110 kn)
- Range: 265 mi (426 km, 230 nmi)
- Service ceiling: 9,450 ft (2,880 m)
Soviet 16-passenger transport helicopter, used by Soviet and affiliated military and civil operators. Also built in China by Harbin Aircraft Manufacturing as the Z-5. Clearly inspired by the Sikorsky H-19 Chickasaw, but much bigger and more powerful, with a couple of special features of its own: rear clamshell doors with a vehicle loading ramp, and (in military versions) a gondola beneath the nose for a machine gunner.
- Produced: 1953–1979
- Number built: over 4,000 (over 3,400 by Mil, 558 Harbin Z-5)
- Capacity: 16 passengers (plus 2 crew)
- Maximum takeoff weight: 16,645 lb (7,550 kg)
- Engine: Shvetsov ASh-82V 14-cylinder radial, 1,680 hp (1,250 kW)
- Maximum speed: 115 mph (185 km/h, 100 kn)
- Range: 310 mi (500 km, 270 nmi)
- Service ceiling: 18,000 ft (5,500 m)
American 12-to-18-passenger transport, utility, and anti-submarine warfare helicopter, used by the U.S. military and other militaries as well as civil operators. Built under license in France by Sud-Aviation; also built under license in turboshaft form in Britain as the Westland Wessex.
- Produced: 1954-1970
- Number built: 2,108
- Capacity: 18 passengers (plus 2 crew)
- Maximum takeoff weight: 13,300 lb (6,033 kg)
- Engine: Wright R-1820-84 Cyclone 9 9-cylinder radial, 1,525 hp (1,137 kW)
- Maximum speed: 122 mph (196 km/h, 106 kn)
- Range: 190 mi (310 km, 170 nmi)
- Service ceiling: 12,000 ft (3,700 m)
American four-seat tandem-rotor anti-submarine warfare helicopter, equipped with sonar and armed with two Mk 43 lightweight anti-submarine torpedoes. Tested in small numbers by the U.S. Navy before being prematurely retired in 1960; most of the examples produced were never used. Heaviest, most powerful helicopter ever to use a single piston engine, and the only tandem-rotor helicopter ever built by Bell.
- Introduced: 1957
- Number built: 53
- Capacity: 4
- Maximum takeoff weight: 26,500 lb (12,020 kg)
- Engine: Pratt & Whitney R-2800-50 Double Wasp 18-cylinder radial, 2,100 hp (1,600 kW)
- Maximum speed: 124 mph (200 km/h, 108 kn)
- Range: 350 mi (560 km, 300 nmi)
- Service ceiling: 14,400 ft (4,400 m)
Twin-engined large piston helicopters
[edit]Very large helicopters powered by twin piston engines. Few such helicopters were ever built in quantity; most either never got past the prototype stage or were converted to turboshaft power before reaching production. The only exceptions were the Yakovlev Yak-24 and the Sikorsky H-37 Mojave. These had maximum takeoff weights of around 30,000 to 35,000 pounds, were powered by twin air-cooled radial engines of around 1,500 to 2,000 horsepower, and could seat 26 to 40 passengers or carry several tons of cargo, either internally or externally.
Such extreme piston-engined helicopters were short-lived; by the time they reached service in the middle 1950s, turboshafts were already replacing large piston engines, so these craft were rendered obsolete almost as soon as they were born.
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Soviet 40-passenger twin-engine tandem-rotor transport and heavy-lift helicopter, used by the Soviet Air Force and possibly Aeroflot. The largest ever piston-engined production helicopter. The rear end had a ramp-type door for loading.
- Introduced: 1955
- Number built: 40-100 (sources differ)
- Capacity: 40 passengers (plus 4 crew)
- Maximum takeoff weight: 34,900 lb (15,830 kg)
- Engines: two Shvetsov ASh-82V 14-cylinder radials, 1,700 hp (1,300 kW) each
- Maximum speed: 109 mph (175 km/h, 94 kn)
- Range: 165 mi (265 km, 143 nmi)
- Service ceiling: 8,900 ft (2,700 m)
American 26-passenger twin-engine transport and heavy-lift helicopter, used by the U.S. Army and Marines. The largest production helicopter in the West at the time, and the most powerful ever piston-engined production helicopter. The nose had clamshell doors with a ramp for loading. The engines were mounted in external nacelles to free up interior space, and the main landing gear retracted into these nacelles.
- Produced: 1956-1960
- Number built: 154
- Capacity: 26 passengers (plus 3 crew)
- Maximum takeoff weight: 31,000 lb (14,061 kg)
- Engines: two Pratt & Whitney R-2800-54 Double Wasp 18-cylinder radials, 2,100 hp (1,600 kW) each
- Maximum speed: 130 mph (209 km/h, 113 kn)
- Range: 145 mi (233 km, 126 nmi) with maximum payload
- Service ceiling: 8,700 ft (2,650 m)