The Yak-42 is a medium-range, three-engine passenger aircraft developed by the Yakovlev Design Bureau in the mid-1970s to replace the aging Tu-134.
Development
Development began in 1972 at the request of Aeroflot, which needed a new medium-range airliner. Designers chose a three-engine layout similar to the Yak-40 and Tu-154: two engines mounted at the rear of the fuselage and a third within the fuselage with an intake in the tail fin, paired with a T-tail configuration.
The first prototype was built at the Smolensk Aviation Plant in late 1974. The aircraft was shown at the 1977 Paris Air Show at Le Bourget. Its airworthiness certificate was issued on December 18, 1980.
Design Features
The Yak-42 is an all-metal low-wing monoplane with a semi-monocoque fuselage. Notable features:
- Powerplant: three D-36 turbofan engines with a high bypass ratio (5.4), each producing 6,500 kgf of takeoff thrust
- Fuselage: matching the Tu-154 in width, but more technologically advanced
- Wing: a one-piece swept (23°) box-torsion design, eliminating heavy joint fittings
- Landing gear: a tricycle arrangement with four-wheel bogies on the main gear
- Boarding stairs: built into the tail section
Specifications
- Length: 36.38 m
- Wingspan: 34.88 m
- Height: 9.83 m
- Cruise speed: 700 km/h
- Max speed: 810 km/h
- Range: 2,790 km (Yak-42), 4,000 km (Yak-42D)
- Max takeoff weight: 57.5 t
- Crew: 3
- Passengers: 120
- Fuel burn: 2,300–3,100 kg/h
Production and Service
Series production began in 1977, and Aeroflot began passenger service in late 1980. A crash on June 28, 1982 (registration CCCP-42529), led to a two-year halt in production and operations while design flaws were addressed.
In 1988, production began on the upgraded Yak-42D, with greater range and higher maximum takeoff weight. In total, 183 production aircraft were built: 11 at the Smolensk Aviation Plant (1977–1981) and 172 at the Saratov Aviation Plant (1978–2003).
Variants
- Yak-42: the original model
- Yak-42D: an upgraded variant with increased fuel capacity
- Yak-42D-100: a variant fitted with Western avionics
- Yak-42M: an upgraded version with D-436M engines (never entered series production)
The Yak-42 in the 1990s
By the mid-1990s, the Yak-42 remained one of the relatively modern Soviet passenger aircraft. Its low landing speed (200–205 km/h) and ability to operate from poorly equipped airfields made it attractive for regional service. Converting one into a business jet was a popular choice for wealthy clients, since it offered a spacious cabin and good range.