Lavochkin La - 150 The Lavochkin La - 150 ( also known as the " Izdeliye " 150 – Aircraft or Article 150 , USAF / DOD designation Type 3 ) , was designed by the Lavochkin design bureau ( OKB ) in response to a 1945 order to build a single - seat jet fighter using a single German turbojet . By this time both the Americans and British , as well as the Germans , had already flown jet fighters and the single Soviet jet engine under development ( the Lyulka TR - 1 ) was not yet ready for production . The design was completed quickly , but the construction of the five flying prototypes was protracted by the factory ' s inexperience in building metal aircraft . The aircraft made its first flight in September 1946 , but proved to require extensive modifications to meet the Soviet Air Forces ' requirements . These took so long to make and test that the aircraft was essentially obsolete by the time that they were completed . Even one variant with a much more powerful engine was inferior to other aircraft that the OKB had under development and all work was terminated in 1947 . Design and development . The Lavochkin OKB was ordered to design a fighter using a single Junkers Jumo 004 B axial - flow turbojet in February 1945 . Much like their rivals at the Mikoyan - Gurevich OKB with their MiG - 9 , the OKB chose a " pod - and - boom " layout for their new fighter , based on advice from the Central Aerohydrodynamic Institute ( TsAGI ) , although their design had a shoulder - mounted wing . The wings of the all - metal aircraft had fixed leading edges and slotted flaps . The cockpit was well forward , giving the pilot good visibility , and he was protected by an armored headrest . The windscreen of the teardrop - shaped canopy was also armored . Two Nudelman - Suranov NS - 23 autocannon were mounted on the lower side of the fuselage with 75 rounds per gun . The tricycle landing gear retracted into the fuselage which gave the 150 a very narrow track . The Soviet derivative of the Jumo engine , the RD - 10 , was rated at and was mounted behind the cockpit . A steel heat shield protected the bottom of the rear fuselage from the engine ' s exhaust . Air was supplied by an intake in the aircraft nose that split around the cockpit before reaching the engine . Seven tanks , five in the fuselage and one in each wing , carried a total of of fuel . Construction of a full - scale mockup was completed in June 1945 by Factory No . 81 , but the order for five prototypes was given to Factory No . 381 as Factory No . 81 was already fully committed to other programs . Manufacturing drawings were delivered to Factory No . 381 by the end of August , but the prototypes were delayed because the plant had no experience building metal aircraft and lacked the necessary tooling . By the end of the year , the factory had only managed to complete a single airframe for static load testing . This showed that the rear fuselage , wings and tail needed to be reinforced , and the opportunity was taken to enlarge the vertical stabilizer as well . These tests and modifications required six months of work so that the first flying prototype was not completed until July 1946 . Manufacturer ' s testing of the first prototype began on 27 August , after ground testing had required replacing the engine twice , and the first flight was made on 11 September . The following day , the Council of Ministers ordered that a small batch of jets from each OKB were to participate in the 7 November parade commemorating the October Revolution . Because of the tight deadline , the components for the two incomplete prototypes were turned over to Factory No . 301 at Khimki , the new headquarters for the Lavochkin OKB , for assembly by Factory No . 381 . Factory No . 21 in Gorky joined the program with three more aircraft built in record time with support from Factory No . 301 . Tooling was constructed in 5 – 10 days with the first aircraft completed in a week and a half . Testing and evaluation . All eight aircraft were complete by 1 November and had been tested to ensure their readiness to participate in the parade . They were later given the unofficial service designation of La - 13 . It was considered too risky to fly the aircraft from Gorky to Moscow and their wings could not be dismounted which meant that they could not be railed to Moscow either . Special three - wheeled trailers were built and the aircraft were driven to Moscow , but the flypast was cancelled because of bad weather . The tests conducted in preparation for the parade revealed a number of flaws in the design including poor directional stability , a cramped cockpit without heating or ventilation , poor access to the engine , inadequate fuel capacity , compounded by the lack of a fuel gauge , and poor elevator control forces . Five aircraft were modified to correct these issues before resuming the factory ' s testing in late 1946 . The modifications were not entirely successful and the lateral stability was now too great and the elevator forces remained too weak . Engine problems , however , plagued the tests as the first prototype alone required four engine changes . After the conclusion of the manufacturer ' s trials in April 1947 , one aircraft was returned to the factory for extensive modifications as the 150M . The wing tips were angled downward 35° to reduce the lateral stability , the wing was redesigned to detach from the fuselage , and the aerodynamic balancing of the elevators was reduced from 24 % to 20 % . The fuel capacity was increased to , the cockpit was widened by and fitted with an ejection seat . Fore and aft armor plates were fitted to protect the pilot and a new radio aerial mast was installed . All these changes added of weight and increased drag which reduced the aircraft ' s top speed by , and slowed its time to from 4 . 8 to 7 . 2 minutes in comparison to the unmodified aircraft . Given that a higher - performance design , the Aircraft 156 , had already been submitted for state acceptance trials , Semyon Lavochkin decided not to continue the development of the 150M . In the meantime , the OKB had been developing two afterburning versions of the RD - 10 in an effort 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 150 prototype in July 1947 , designated as the 150F . The additional power increased the aircraft ' s top speed to at sea level and at an altitude of . This made the 150F the second - fastest Soviet fighter of the period , after the MiG - 9 powered by two afterburning RD - 21 engines . Nevertheless , Lavochkin decided not to submit the 150F for state acceptance trials as the fundamental design flaws of the airframe still had not been resolved .