https://en.wikipedia.org/wiki/Yakovlev_Yak-24
The Yakovlev Yak-24 (NATO reporting name Horse) was a twin-engine, tandem rotor
transport helicopter developed in the USSR.
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,
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).
Role
Transport helicopter
Manufacturer
Yakovlev
First flight
3 July 1952
Introduction
1955
Status
Retired
Primary users
Soviet Air Force
Aeroflot
Number built
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.
A surviving Yak-24 is preserved at the Central Air Force Museum at Monino,
outside of Moscow.
Specifications (Yak-24U)
General characteristics
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)
Empty weight: 11,000 kg (24,251 b)
Max. takeoff weight: 15,830 kg (34,898 lb)
1,268 kW (1,700 hp each) each
Performance
Maximum speed: 175 km/h (94 knots, 109 mph)
Range: 265 km (143 nmi, 165 mi)
Service ceiling: 2,700 m (8,900 ft)
*
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