Known internally as "Product 48", the Yak-141 was intended to replace the Yak-38 in service with the Soviet Navy. It went through significant design evolution. Configurations studied by Yakovlev included a twin-engine configuration, which was rejected due to asymmetric thrust issues in the event of an engine failure during landing, and a single-engined configuration, with lift jets to allow for vertical takeoff and landing, was selected. The engines were controlled digitally; manuverability during the hover was provided by reaction control jets, using excess airflow from the engines, located at the wingtips and under the nose. The pressurised cockpit was fitted with an automatic
ejection seat; the automatic functionality would be armed when the engine duct was rotated past 30° when at an airspeed of less than . The prototypes had a cockpit arrangement similar to that of the Yak-38M; the production aircraft were planned to be fitted with an entirely new digital system including a
helmet-mounted sight. The aircraft's landing gear was of the tricycle type; the nosewheel retracted to the rear, the main wheels retracting forwards. The wing was mounted high on the fuselage, and was foldable to allow for compact storage on board
aircraft carriers. The main engine was a
Tumansky R-79V-300, while the lift jets were a pair of
Rybinsk (RKBM) RD-41s, installed at an angle of 85° in the forwards fuselage behind the cockpit. Four prototypes were built; the first was a static-test article, the second a nonflying testbed, while the third and fourth prototypes would be used for flight testing ==Operational history==