Lavochkin La - 152 The Lavochkin La - 152 , ( USAF reporting name - Type 4 ) , and its variants , was a jet fighter prototype designed and manufactured by the Lavochkin Design Bureau ( OKB ) shortly after the end of World War II . Derived from the Lavochkin La - 150 , the 152 used several different engines , but the program was canceled as other fighters with more powerful engines and swept wings showed more promise . Design and development . " Izdeliye " 152 . Following the limited success of the 150 , drastic changes were introduced to improve performance and ease of maintenance . The RD - 10 engine , rated at of thrust , was moved to the front of the nose and its cowling formed the bottom of the forward fuselage . This position minimized thrust losses due to the length of the intake duct and allowed the engine to be changed much more easily than its predecessor . The cockpit was widened and moved to a position over the mid - set wings , even with the engine ' s exhaust nozzle . The pilot ' s seat back was armored and he was protected by an armor plate to his front and a bulletproof windscreen . Three fuel tanks were positioned ahead of the cockpit and one behind it with a total capacity of of fuel . The removable , mid - mounted wings used several different laminar flow airfoil s over their span . Each wing had a single spar , slotted flaps and ailerons . The tricycle undercarriage retracted into the fuselage , which meant that the aircraft had a very narrow ground track . The aircraft was armed with three Nudelman - Suranov NS - 23 autocannon , two on the starboard side of the aircraft ' s nose and the other on the port side . Each gun had 50 rounds of ammunition . The 152 made its first flight on 5 December 1946 and the manufacturer ' s trials completed on 23 June 1947 . State acceptance trials commenced on 12 July , but the prototype crashed on the eighth flight when the engine failed on approach . The maximum speed attained by the 152 before its crash was only . " Izdeliye " 154 . The Lavochkin OKB decided to improve the performance of the 152 in late 1946 by replacing the RD - 10 engine with a more powerful Lyulka TR - 1 turbojet of thrust . The design work was completed in September 1947 , and construction began of a prototype shortly afterward , but the engine was not yet ready for testing and the project was canceled . The only other significant difference from the 152 was that each cannon was furnished with 75 rounds of ammunition . " Izdeliye " 156 . Meanwhile , the OKB had been developing two afterburning versions of the RD - 10 to increase the engine ' s power . The more successful model was only longer and weighed an additional more than the original engine . Its power , however , was increased by an additional , over 30 % more thrust . This engine was designated the " izdeliye YuF " by the bureau and was fitted into an aircraft 152 prototype in November 1946 , initially designated as the 150D ( " Dooblyor " - Second ) . This was changed to Aircraft 156 the following month . In addition to the more powerful engine , the aircraft now had an ejection seat , additional cockpit armor , and a revised canopy . More importantly , it was fitted with new wings with a greater span and more surface area ; they also had a new airfoil designed to delay Mach tuck . The area of the tailplane and the vertical stabilizer was also increased . Two prototypes were built and the first one was completed in February 1947 and made its first flight on 1 March . The second prototype joined the manufacturer ' s trials later that month . One of these aircraft participated in the Tushino flypast on 3 August 1947 , where it was given the USAF reporting name of Type 5 . The additional power increased the aircraft ' s top speed by over the 152 . The second prototype began state acceptance trials on 9 September and demonstrated a maximum speed of at an altitude of . It could reach in four minutes using afterburner . The aircraft was rejected by the Soviet Air Forces when the trials were concluded on 28 January 1948 . The report said that the " YuF " engine was required more work before it was ready for production , the aircraft had problems with longitudinal stability , excessive stick forces from the ailerons and elevators , and the undercarriage was troublesome . Lavochkin consequently canceled the program . " Izdeliye " 174TK . An experimental version of " Izdeliye " 156 was built in 1947 under the name of " Izdeliye " 174TK ( " Tonkoye Krylo " - thin wing ) . It had a very thin , straight wing of 6 % thickness , believed to be the thinnest yet flown in the world , and an imported Rolls - Royce Derwent V engine , rated at , mounted in the nose . The three NS - 23 cannon had to be repositioned on the bottom of the nose to accommodate the engine . It was first flown in January 1948 and had a top speed of at sea level . It reached an altitude of 5 , 000 meters in only 2 . 5 minutes , but even these impressive gains over the 156 were inferior to the swept - wing Lavochkin La - 160 that had flown nine months earlier and the program was canceled .