Yakovlev Yak-24

Yakovlev Design Bureau

Industry	Aerospace
Founded	1934
Founder	Alexander Yakovlev
Headquarters	Moscow , Soviet Union

The Yakovlev Yak-24 (NATO reporting name "Horse") was a twin-engine, tandem rotor transport helicopter developed in the Soviet Union during the 1950s by the Yakovlev Design Bureau. It was operated in limited numbers by the Soviet Air Force, though precise figures regarding production totals and service duration remain unclear due to conflicting information.

Design and development

In September 1951, after a conference involving Joseph Stalin and top aircraft engineers, the Soviet government issued two helicopter design requirements aimed at expediting rotorcraft advancement. The medium-lift specification, intended to carry twelve passengers, was assigned to the Mil Design Bureau, resulting in the Mil Mi-4. Meanwhile, the larger transport category, capable of accommodating 24 passengers, was commissioned to the Yakovlev Design Bureau under the leadership of Alexander Yakovlev. Both projects were mandated to have flying prototypes within one year, with extensive support provided by national research organizations. Yakovlev produced two prototypes for flight evaluation plus an additional airframe for static and dynamic ground tests. The initial prototype took to the air on 3 July 1952. Powered by two 1,268 kW (1,700 hp) Shvetsov ASh-82V radial engines arranged in a tandem rotor configuration—uncommon among Soviet helicopters—it earned the nickname Letayushchiy Vagon (Russian: Летающий вагон), meaning 'Flying Railroad Car'. Its engines and transmission system were similar to those used in the single-engine Mil Mi-4, but the Yak-24 encountered more challenges. The interconnected engine setup allowed each engine to drive one or both rotors; however, this design induced significant airframe vibrations. After partial resolution of these issues, production was approved for the Soviet Air Force beginning in 1955 at Factory No. 272 located in Leningrad.

The Yak-24 was unveiled publicly at Tushino airfield in July 1955. Later that year, on 17 December, it established two world payload records by lifting a 2,000 kg (4,409 lb) load to an altitude of 5,082 m (16,673 ft) and hoisting a 4,000 kg (8,818 lb) load up to 2,902 m (9,521 ft).

The sole production model was the Yak-24, a military transport helicopter capable of carrying up to nineteen paratroopers, twelve stretchers, or approximately 2,000 kg (4,409 lb) of cargo such as field artillery or a GAZ-69 military vehicle. A radio operator manned a nose-mounted 12.7 mm A-12.7 machine gun. Additionally, the Yak-24 served as a flying crane able to lift external loads weighing up to 4,000 kg (8,818 lb). In 1957 an enhanced version designated Yak-24U was developed by modifying existing helicopters; it featured all-metal rotors with increased diameter (21 m/69 ft) and a wider all-metal fuselage. This variant could transport forty soldiers or carry up to 3,500 kg (7,716 lb) of freight including an ASU-57 tank destroyer. Although it completed testing in 1958, it did not proceed into mass production. A civilian version intended for Aeroflot accommodating thirty passengers—the Yak-24A introduced in 1960—also failed to enter manufacturing. Proposed but unbuilt variants included the Yak-24K, a nine-seat VIP configuration with shortened fuselage, and the Yak-24P, a civilian model seating thirty-nine passengers powered by more potent 2,013 kW (2,700 hp) turboshaft engines. Neither design advanced beyond planning stages. Due to limited exposure and scarce documentation, technical specifications vary across sources; some older references mistakenly report production of the Yak-24U and passenger Yak-24A.

Information about the Yak-24 is often inconsistent and contradictory; estimates of total units produced range from forty to one hundred depending on source. Recent Russian research indicates only thirty-five serial helicopters were manufactured between 1956 and 1958 in Leningrad alongside two prototypes and three pre-production examples built from 1953 to 1958. All accounts agree that production ceased due to persistent technical difficulties and that operational requirements for heavy transport helicopters were ultimately met by the successful Mil Mi-6. Some reports suggest that Aeroflot never actually received any Yak-24A passenger models. The precise retirement date of the Yak-24 from Soviet Air Force service—and possibly Aeroflot—is unknown. One preserved example is exhibited at the Central Air Force Museum located in Monino, Russia.

Operators

Template:USSR

• Soviet Air Force

Specifications (Yak-24U)

File:Yakolev Yak-24U ’51 red’ (39137897382).jpg

Yak-24U displayed at the Central Air Force Museum

References

• Gordon, Yefim; Komissarov, Dmitry; Komissarov, Sergey. OKB Yakovlev: A History of the Design Bureau and its Aircraft. Hinckley, UK: Midland Publishing, 2005. ISBN 1-85780-203-9.
• Gunston, Bill. The Osprey Encyclopedia of Russian Aircraft 1875–1995. London: Osprey, 1995. ISBN 1-85532-405-9.
• Gunston, Bill; Gordon, Yefim. Yakovlev Aircraft since 1924. London: Putnam, 1997. ISBN 0-85177-872-0.
• Stroud, John. Soviet Transport Aircraft since 1945. London: Putnam, 1968. ISBN 0-370-00126-5.
• Yakubovich, N.V. Vyertolot Yak-24. Aviakollektsya series vol. 3/2011. Moscow, 2011 (in Russian).