The Yakovlev Yak-24 (NATO reporting name Horse) was a twin engine, tandem rotor transport helicopter developed in the USSR.
History
The Yak-24 was designed in the construction bureau of
Alexander Sergeyevich Yakovlev, not specializing in helicopters so far, to meet a demand for a heavy transport helicopter to supplement the medium
Mil Mi-4. The first prototype was flown on 3 July, 1952. It was powered with two 1,700 hp
Shvetsov ASh-82V radial engines and was built in a tandem rotor layout, not typical for Soviet helicopters, which soon brought it nick-name
Letayushchiy Vagon (Летающий вагон) - 'the Flying Railroad Car'. The engines and transmission system were the same, as already proven in the single-engine Mi-4, but the Yak-24 appeared not as successful design. Its engines were linked together so each could drive one or both rotors, but such arrangement caused strong vibrations. After problems were partially solved, the new helicopter was order for production, which started in 1955. In July
1955 it was first presented to the public, and on
17 December 1955 it set two new world payload records, lifting a 2,000 kg load to 5,082 m and 4,000 kg to 2,902 m.
Initial variant was the Yak-24 - Army transport helicopter, that could carry up to 30 airborne troops, 18 stretchers or 3,000 kg of cargo. From 1958, the improved model Yak-24U was produced, with all-metal rotors of bigger diameter (21 m) and all-metal fuselage. It could carry 40 soldiers or 3,500 kg of cargo, including 2 GAZ-69 jeeps or anti-tank guns. A civilian variant for 30 passengers was the Yak-24A, produced from 1960 in a small series. It was also used as a flying crane, lifting an external load of 5,000 kg. There were two proposed models: the Yak-24K 9-seat VIP salon with shorter fuselage and civilian Yak-24P for 39 passengers with stronger 2,700 hp turboshaft engines, but they were not built.
Exact number of produced Yak-24 helicopters is not sure, but due to technical problems, the series was very small. The need for a heavy transport helicopter was satisfied with the successful Mil Mi-6 by then. Most often a number of about 100 produced Yak-24 helicopters is given, some sources state about 40. According to some sources, the passenger Yak-24A was not actually produced.
Operators
Specifications (Yak-24)
See also
