The Yakovlev Yak-141 (Russian: Яковлев Як-141; NATO reporting name "Freestyle"), also known as the Yak-41, is a Soviet supersonic vertical takeoff/landing (VTOL) fighter aircraft designed by Yakovlev. Intended as a replacement for the Yak-38, it was designed as a supersonic fleet defence fighter capable of STOVL/VTOL operating from Soviet carriers. Four prototypes were built before the project's cancellation. Yakovlev always believed the Yak-38 to be an interim aircraft, developed to gain experience designing and developing military VTOL aircraft. Even before the Yak-38's introduction, the Soviet Navy desired a more comprehensive aircraft, with greater capabilities than the Yak-38 offered. The result was a design contract offered to Yakovlev in 1975. The requirement was for an aircraft with only one mission: air defense of the fleet. Unlike the Yak-38, this aircraft was to have sustained supersonic speed. Maneuverability, radar and weapons loads were expected to be similar to those of current front-line fighters, such as the Su-27 and MiG-29. For the Soviet Navy this aircraft was to be their next generation VTOL fighter. For Yakovlev the aircraft was viewed as a way of returning to designing Soviet fighter aircraft. Because of the importance and complexity of the project, Alexander Sergeyevich Yakovlev assigned a large portion of his OKB to the development of the new VTOL fighter, with no fewer than ten chief engineers working simultaneously on what was called "Product 48" (the military had designated it Yak-41). Over fifty designs were studied. One key problem was designing an aircraft with both vectoring thrust and an afterburner, which was essential for sustained supersonic speeds. A twin-engine design was considered, but abandoned as the loss of an engine on landing would result in an immediate roll to the side. Eventually it was decided that the best arrangement was a single vectoring nozzle located just behind the center of gravity, as well as dedicated vertical thrust jets positioned just behind the cockpit. A considerable amount of time was spent in the development of a flat, rectangular nozzle similar to that later employed on the American F-22 Raptor. Such a nozzle proved well-suited for the changes in configuration needed for both thrust vectoring and supersonic flight, and allowed for a thin, shallow tail. Ultimately, a circular nozzle was used, located between twin booms supporting the twin-finned tail. Yak-41 or Yak-141 The design was initially designated the Yak-41M by the Soviet military. Once testing commenced, and the two prototypes began accumulating numerous world class records, it became necessary to invent a designation for use in the west, as the name Yak-41M was classified. The designation Yak-141 was selected, and it was by this name that the aircraft became known to western allies, though officially the aircraft's designation remained Yak-41M within the Soviet military. In 1991 Lockheed-Martin entered into partnership with Yakovlev to further develop an aircraft they had always known as the Yak-141. Largely as a result of this agreement, by 1992 Yakovlev changed the aircraft's designation to Yak-141 for the two flyable prototypes. Series production in Russia could further change the designation. Four were built. For more details of design and development, operational history and variants, click here.
