The Yakovlev Yak-140 was a Soviet prototype lightweight supersonic fighter developed during the 1950s. The prototype was completed in 1954, but it was denied authorization to enter flight testing and the program was cancelled in 1956.

Development

The Yak-140 was developed around the Mikulin AM-11 turbojet (rated at thrust dry and with afterburner) to meet a specification issued in 1953 requiring a supersonic fighter with a maximum speed of and a range of . It was to be armed with three cannon with 75 rounds per gun and was to be capable of carrying air-to-ground rockets as well as of bombs. Its fully loaded weight was to be and it was to be ready to be submitted for State acceptance trials in March 1955.Gordon, et al., p. 190 The fighter had a circular-section semi- monocoque fuselage with a nose air intake. A range-only radar was fitted in the conical inlet cone of the air intake. The wings had a sweep angle of 55° at quarterchord. Two

wing fence Wing fences, also known as boundary layer fences and potential fences are fixed aerodynamic devices attached to aircraft wings. Often seen on swept-wing aircraft, wing fences are flat plates fixed to the upper surfaces parallel to the wing ch ...

s were fitted on the upper surface of each wing. The horizontal stabilizer was midway down the rear fuselage and two air brakes were fitted on its underside. The

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

canopy was faired into the spine that ran the length of the top of the fuselage. The

tandem landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

had a single wheel on the forward unit and twin wheels on the main unit with outrigger struts that retracted aft into wingtip fairings.Gunston, p. 488 The aircraft's State acceptance trials were delayed until the first quarter of 1956 for lack of a flight-ready AM-11 engine, but it had to be adapted to use a less powerful

Mikulin AM-9 The Tumansky RD-9 (initially designated Mikulin AM-5) was an early Soviet turbojet engine, not based on pre-existing German or British designs. The AM-5, developed by scaling down the AM-3, was available in 1952 and completed testing in 1953; ...

D engine with only of dry thrust. The gun armament was reduced to only two Nudelman-Rikhter NR-23 guns with 75 rounds per gun in compensation, but the estimated speed dropped by about regardless. This was deemed to be acceptable as it sufficed to begin flight testing. The prototype was completed in December 1954 and it passed all the necessary ground tests by 10 February 1955 when it was cleared to begin flight trials. However, the ( Ministry of Aviation Industry (MAP)) denied Yakovlev authorization to begin flight tests as it favored competing designs from Sukhoi and Mikoyan-Gurevich. A

Council of Ministers A council is a group of people who come together to consult, deliberate, or make decisions. A council may function as a legislature, especially at a town, city or county/shire level, but most legislative bodies at the state/provincial or natio ...

directive was issued on 28 March 1956 to terminate the program and the corresponding MAP order followed on 6 April.

Specifications (with AM-9D (estimated))

Notes

Bibliography

* * {{Yakovlev aircraft Yak-140 1950s Soviet fighter aircraft Abandoned military aircraft projects of the Soviet Union