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|First flight||3 July 1952|
|Primary users||Soviet Air Force
Design and development
In late summer 1952, the Soviet Union issued two design specifications for helicopters, with the intent of catching up to the United States in post-World War II helicopter development. The design for the a medium size helicopter which could transport 12 people was issued to the Mil Design Bureau, whereas the design for a larger version capable transporting 24 people was given to the Yakovlev Design Bureau, which had not had any previous design experience with helicopters prior to this project.
Yakovlev made two prototypes for flight testing, and two more for static and dynamic ground tests. The first prototype was flown on 3 July 1952. It was powered with two 1,268 kW (1,700 hp) Shvetsov ASh-82V radial engines and was built in a tandem rotor layout, which was not typical for Soviet helicopters, which soon brought it the nickname Letayushchiy Vagon (Летающий вагон) – 'the Flying Railroad Car'. The engines and transmission system were identical to the already-proven single-engine Mil Mi-4, but the Yak-24 proved to be less successful. Its engines were linked together so each could drive one or both rotors, but such an arrangement caused strong vibrations in the airframe. After the problems were partially solved, the new helicopter was ordered for production, which began in 1955.
In July 1955, the Yak-24 was first presented to the public, and on 17 December 1955 it set two new world payload records, lifting a 2,000 kg (4,409 lb) load to 5,082 m (16,673 ft) and 4,000 kg (8,818 lb) to 2,902 m (9,521 ft).
The initial variant was the Yak-24 – Army transport helicopter, that could carry up to 30 airborne troops, 18 stretchers or 3,000 kg (6,614 lb) of cargo. From 1958, the improved model Yak-24U was produced, with all-metal rotors of larger diameter (21 m/69 ft) and an all-metal fuselage. It could carry 40 soldiers or 3,500 kg (7,716 lb) of cargo, including two GAZ-69 jeeps or anti-tank guns. A civilian variant for 30 passengers was the Yak-24A, produced from 1960 in small numbers. It was also used as a flying crane, lifting an external load of 5,000 kg (11,023 lb). There were two proposed models: the Yak-24K nine-seat VIP salon with a shorter fuselage and the civilian Yak-24P for 39 passengers with stronger 2,013 kW (2,700 hp) turboshaft engines, but neither reached production.
The exact number of Yak-24 helicopters produced is unknown with estimates ranging from 40 to 100 units, depending on the source of the data. All sources agree that production was curtailed due to technical problems, and the need for a heavy transport helicopter was fulfilled by the successful Mil Mi-6. According to some sources, the passenger Yak-24A was not actually produced.
Data from Soviet Transport Aircraft since 1945
- Crew: four (two pilots, flight engineer and radio operator)
- Capacity: 40 soldiers, 18 stretchers, or 3,500 kg (7,716 lb) of cargo
- Length: 21.34 m (70 ft 0 in)
- Rotor diameter: 21.0 m (68 ft 3 in)
- Height: 6.50 m (24 ft 4 in)
- Disc area: 693 m² (7,454 ft²)
- Empty weight: 11,000 kg (24,251 b)
- Max. takeoff weight: 15,830 kg (34,898 lb)
- Powerplant: 2 × Shvetsov ASh-82V 14-cylinder two-row air-cooled radial engines, 1,268 kW (1,700 hp each) each
- Maximum speed: 175 km/h (94 knots, 109 mph)
- Range: 265 km (143 nmi, 165 mi)
- Service ceiling: 2,700 m (8,900 ft)
- Aircraft of comparable role, configuration and era
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- Stroud 1968, pp. 268–269.
- Gunston 1995, p. 480.
- Fuselage length. Overall length (including rotors): 34.03 m (111 ft 7¾ in)