Yakovlev Yak - 141 The Yakovlev Yak - 141 ( ; NATO reporting name " Freestyle " ) , also known as the Yak - 41 , was a supersonic vertical takeoff / landing ( VTOL ) fighter aircraft designed by Yakovlev . It did not enter production . Design and development . 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 without any competition . 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 . 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 . Parts subject to excessive heat from the engines during landing were manufactured of titanium , and no less than 26 % of the overall aircraft was to be manufactured of graphite or composite material . Because of heat build - up , hovering was restricted to no more than 2½ minutes . All three engines were controlled through an interlinked digital system , which was capable of controlling both engine start - up as well as modulating the thrust of all three engines during landing and hovering flight . Twin tandem reaction control jets were positioned at the wingtips , while a swiveling yaw jet was positioned under the nose . The cockpit was pressurized and air - conditioned . The small canopy was bulletproof in front . It hinged to the right , but because of a long dorsal spine it had no rear vision . The ejection seat was automatically armed as soon as the engine duct was rotated past 30 degrees with an airspeed of less than 300 km / h ( 186 mph ) . The instrumentation in the prototypes was simple and similar to that planned for the earlier Yak - 36M . The production version was to have been fitted with an extensive avionics and weapons suite including doppler radar , laser - TV ranging and aiming , as well as a heads - up multifunction display ( HUD ) which worked in connection with a helmet - mounted missile aiming system as found on the Mikoyan MiG - 29 . This system allows the pilot to lock onto an enemy aircraft by turning his head as far as 80 degrees from front . The undercarriage was tricycle , and equipped with the latest multi - disc , anti - skid brakes . The steerable nose wheel retracted to the rear , while the main gear retracted forward . The top - mounted wing was similar to that of the Yakovlev Yak - 36 , though the outer panel swept back , and could be folded up for shipboard storage . The main engine was served by four side - mounted ducts as well as a row of large louvers along the upper surface to allow air to enter the engine during full power hovering . This engine was the R - 79V - 300 , a two - shaft augmented turbofan with a bypass ratio of 1 . Maximum thrust was 14 , 000 kg ( 30 , 864 lb ) . The rear nozzle could rotate from 0 degrees to 95 degrees for VTOL landing and hovering . The two lift engines were the RD - 41 design , a simple single - shaft engine made mostly of titanium . Each had a thrust of 4 , 100 kg ( 9 , 040 lb ) . The engines were installed behind the cockpit at an angle of 85 degrees . Like the Yak - 38 , the engines received their air through eight spring - operated dorsal flaps , and the exhaust exited through a belly opening covered by two ventral doors . Operational history . Yakovlev obtained funding for four prototypes . The first ( 48 - 0 , with no callsign ) was a bare airframe for static and fatigue testing . The second ( 48 - 1 , call sign " 48 " ) was a non - flying powerplant testbed . The third and fourth ( 48 - 2 and 48 - 3 , call signs " 75 " and " 77 " ) were for flight testing . While 48 - 1 remained unpainted , 48 - 2 and 48 - 3 were painted in overall grey , with a black radome and fin cap antennas . The first conventional flight , using 48 – 2 , took place at Zhukovskii on 9 March 1987 , with chief test pilot Sinitsyn at the controls . He made the first hovering flight on 29 December 1989 flying 48 – 3 , and used the same aircraft to make the first complete transition from vertical to high - speed flight and vertical landing on 13 June 1990 . From April 1991 , various kinds of rolling take - off and run - on landings were performed on normal runways and also " ski - jump " ramps at the lift jet center at Saky . Throughout its testing , the aircraft demonstrated excellent combat maneuvers . Chief test pilot Sinitsyn went on to set twelve new world class records , but as the Yak - 41 designation was classified , the records were submitted under the fictitious name " Yak - 141 " . As a result , the previously unknown aircraft came to be known in the west as the " Yak - 141 " . In 1992 , Yakovlev repainted both flying aircraft in olive / grey camouflage , with the Russian tricolor insignia , and painted a white " 141 " on both aircraft in place of their previous call signs , " 75 " and 77 " . On 26 September 1991 , Sinitsyn made the first vertical landing on the Soviet aircraft carrier Admiral Gorshkov ( ex - Baku ) in 48 - 2 . An hour later , Vladimir A . Yakimov landed 48 - 3 on the same deck . The pilots would go on to make eight flights from the ship until Yakimov made a hard landing on 5 October . The undercarriage ruptured a fuel tank , causing a serious fire . After almost 30 seconds , Yakimov ejected successfully , and was rescued from the sea . The aircraft was later repaired and placed on display ( see " Survivors " ) . That same month the Soviet Navy announced that no further funds were available to continue the program . The factory at Smolensk had anticipated this and had not constructed the tooling for production . 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 its designation . Cooperation with Lockheed . Following the announcement by the CIS on September 1991 that it could no longer fund development of the Yak - 41M , Yakovlev entered into discussions with several foreign partners who could help fund the program . Lockheed Corporation , which was in the process of developing the X - 35 for the US Joint Strike Fighter program , stepped forward , and with their assistance 48 - 2 was displayed at the Farnborough Airshow in September 1992 . Yakovlev announced that they had reached an agreement with Lockheed for funds of $ 385 to $ 400 million for three new prototypes and an additional static test aircraft to test improvements in design and avionics . Planned modifications for the proposed Yak - 41M included an increase in STOL weight to 21 , 500 kg ( 47 , 400 lb ) . One of the prototypes would have been a dual - control trainer . Though no longer flyable , both 48 - 2 and 48 - 3 were exhibited at the 1993 Moscow airshow . The partnership began in late 1991 , though it was not publicly revealed by Yakovlev until 6 September 1992 , and was not revealed by Lockheed until June 1994 .