Bereznyak - Isayev BI - 1 Soviet research and development of rocket - powered aircraft began with Sergey Korolev ' s GIRD - 6 project in 1932 . His interest in stratospheric flight was also shared by Marshal Mikhail Tukhachevsky who supported this early work . After a long series of unmanned tests of vehicles , Korolev ' s RP - 318 - 1 rocket plane flew on Feb 28 , 1940 . That Spring , the Zhukovsky Institute in Moscow ( TsAGI ) hosted a conference for aircraft chief designers on the subject of ramjet and rocket propulsion . On July 12 , the Council of People ' s Commissioners ( SNK ) called for the development of high - speed stratospheric aircraft . Early design . Aircraft designer and head of OKB - 293 , Viktor Fedorovich Bolkhovitinov attended the TsAGI conference along with two of his top engineers , A . Ya . Bereznyak and A . M . Isaev . The young Bereznyak had made an impression in 1938 with a high - speed airplane design that some thought could break the world speed record . Bereznyak and Isaev were excited by the idea of designing a rocket - powered aircraft , and their " patron " Bolkhovitinov approved . By the Autumn of 1940 , they were able to show fellow engineer Boris Chertok a preliminary design of " Project G " . The design , made up mostly from plywood and duralumin had a take - off weight of 1500 kg , and they planned to use the new 1400 kgf rocket engine under development in the Jet Propulsion Research Institute ( RNII ) . Chertok was astounded that the aircraft could almost climb vertically . Bereznyak , Isaev and Chertok visited RNII in March 1941 , but the new rocket engine was not working yet . The engine was designed by Leonid Dushkin , who had made the engine ( RD - A - 150 ) for RP - 318 - 1 . Powered by tractor kerosene and red fuming nitric acid , it fell short of the hoped for 1400 kgf of thrust . Designated D - 1 - A - 1100 , it was expected to reach 1100 kgf . The " A " stood for " Nitric " ( versus " Oxygenic " ) , a distinction of unusual importance and controversy among Soviet rocket scientists . Dushkin ' s propellant pump was causing considerable problems . It was a turbine pump driven by hot gas and steam from a small combustion chamber fed with rocket propellants mixed with water . This system was perfected a few years later in Dushkin ' s RD - 2M engine . The D - 1 - A - 1100 was built from carbon steel with diffusion chrome plating . At this point in time , Russian rocket engines were built with typical aviation piston - engine manufacturing technology . Weighing 48 kg , it could be broken down into discrete forged - steel sections – a conical head with 60 centrifugal injectors , the cylindrical chamber , and the nozzle – joined with bolts and copper gaskets . It was ignited with a nichrome glow plug , later replaced with silicon - carbide . The engine was cooled regeneratively by both propellants , the chamber walls by a spiral flow of incoming fuel , and the nozzle section by the flow of oxidizer . War - time development . On June 21 , Isaev proposed a new design using compressed air instead of a pump to force propellant to the engine . The next day , Operation Barbarossa brought the Soviet Union into World War II , and the rocket - powered interceptor suddenly became important . Bereznyak and Isaev began a new more detailed design , which they finished in three weeks . On July 9 , Bolkhovitinov and his project - G team met with Andrey Kostikov the head of RNII . Dushkin was not happy about the idea of bypassing his fuel pump design , but they backed the plan and cosigned a letter that was eventually shown to Joseph Stalin . After giving a report at the Kremlin , they were ordered to build the plane and were given only 35 days to do so . The official order was dated August 1 , but work began in late July . The engineers were given leave to visit their families , and then literally lived at the factory until the planes were finished . The new design was called " BI " for " Blizhnii Istrebitel " ( close - range fighter ) , but the letters were also understood by everyone to stand for its inventors : Bereznyak and Isaev . The original plan to include four machine guns was replaced by a design with a pair of 20 mm ShVAK cannon s . The new plane was a low - wing monoplane 6 . 4 meters long , with a wingspan of 6 . 5 meters and an estimated take - off mass of 1650 kg ( including 710 kg of propellant ) . Working around the clock , local furniture workers were employed to build the first two prototypes ( BI - 1 and BI - 2 ) . The skin was 2 mm plywood with a bonded covering of fabric . The Ailerons , elevators and rudder were fabric covered , and the flaps were duralumin . In the forward section were 5 compressed air tanks and 2 kerosene tanks . In the aft were 5 compressed air tanks and three nitric acid tanks . Pressurized to 60 atm , the tanks were made from a high - strength chromium - manganese - silicon steel ( " Chromansil " ) that was not especially resistant to corrosion . Thus , the acid tanks had to be replaced periodically . Compressed air was also used to retract and deploy the landing gear and to power the anti - aircraft cannons . On September 1 , 1941 , BI - 1 was completed and ready for glider tests by pilot Boris N . Kudrin . Dushkin ' s engine was still not ready . A few weeks later , rival aircraft designer A . S . Yakovlev took it upon himself to tow the prototype to TsAGI for windtunnel testing . This alarmed Bolkhovitinov ' s team , because their patron had a rocky history with Yakovlev , but Alexander Sergeevich and aircraft designer Ilya Florov studied the test results and gave them sound advice for improvements . Yaw instability was corrected by enlarging the rudder and adding two circular plates to the tail horizontal stabilizer . Test flights in the Urals . In October , both OKB - 293 and RNII were evacuated to the Urals , along with most of Moscow ' s war industry . Bolkhovitinov ' s team was stationed in Bilimbay , and Dushkin ' s team in Sverdlovsk , about 60 km away . A test stand was built on the shore of frozen lake Bilimbay , with a dynamometer cradle to hold the BI - 1 during engine testing . A new test pilot , Grigory Yakovlevich Bakhchivandzhi , was assigned to the team . Dushkin was increasingly absorbed by other work , including RNII ' s own rocket plane project , the Kostikov - 302 . He assigned his engineer Arvid V . Pallo to oversee the installation and testing of the rocket engine . Nitric acid presented a constant problem , corroding parts and causing skin burns and respiratory irritation . Tanks of sodium carbonate solution were kept around to neutralize acid spills . On February 20 , 1942 , the engine exploded during a full system test . The nozzle section was blasted into the lake , and the engine head struck the back of the pilot ' s seat , knocking Bakhchivandzhi against the instrument panel and injuring him slightly . From a broken propellant line , pressurized nitric acid drenched Pallo . Fortunately , quick thinking mechanics dunked him head - first into a tank of soda solution . His face was yellow from the characteristic acid staining , but his glasses saved him from being blinded . To protect the pilot in the future , a 5 . 5 mm steel plate was added to the back of the seat . By April 1942 , BI - 1 was ready for testing at nearby Koltsove airfield . A test commission was formed , with representatives from OKB - 293 , RNII and the airforce research lab ( NII VVS ) . On May 2 , the pilot let the plane lift off one meter under low thrust . On May 15 , at 19 : 02 ( UTC ) , Bakhchivandzhi made the first real flight of BI - 1 , reaching an altitude of 840 meters and a maximum speed of 400 km / h . The mass of the plane had been reduced to 1300 kg ( only 240 kg of nitric acid and 60 kg of kerosene loaded ) , and the engine was operated under a thrust of only 500 kgf . The pilot shut the rocket engine off after about one minute , when a light indicated it was overheating . Landing , the aircraft descended too rapidly because of insufficient forward speed , and the landing gear broke on touchdown . The pilot was unhurt and reported that , aside from the rough landing , the plane handled well . The flight lasted only 3 minutes and 9 seconds . In July , Dushkin recalled Pallo to help work on the " 302 " rocket - plane project . Bolkovitinov asked Isaev to take over and master the technology of liquid fuel rocket engines . Isaev got permission to visit Valentin Glushko , the leading Soviet expert on rocket engines , who was then working in a special lab for political prisoners . Glushko taught Isaev the complex techniques of chamber - wall heat transfer calculation and engine design , developed by himself and Fridrikh Tsander in the early 1930s . Isaev ' s propellant feed system was simple , but it produced an uneven fuel pressure that diminished as compressed air was used up . Bolkovitinov and his engineers wrestled with this problem , designing pressure regulators and even a piston fuel pump driven by compressed air , but none of these improvements were realized . Too damaged by acid to fly safely , BI - 1 was retired and the second prototype BI - 2 was made ready . Backchivadzhi made the second flight on Jan 10 , 1943 , reaching 1100 meters but with the engine still throttled back for a maximum speed of 400 km / h . The first flight had been with landing gear kept down , and some vibration has been observed . This time , the flight was made with landing gear stowed , and no vibration was observed at the cautious speed . The third flight was made on Jan 12 ( some sources say Feb 10 ) by a temporary test pilot , Konstantin Gruzdev , while Backchivadzhi was consulting on Kostikov ' s " 302 " project . This time the engine was opened up to full thrust of 1100 kgf and a speed of 675 km / h was achieved and a maximum altitude of 2190 meters . During the winter , the landing gear was switched from wheels to skis . On Gruzdev ' s flight , one ski broke off during take - off , but he was able to land safely . Backchivandzhi returned to make flights in the third test plane BI - 3 on March 11 , 14 and 21 . He reached a maximum altitude of 4000 meters with a maximum rate of climb of 83 meters per second . The March 21 flight was with a full load of ammunition . Most of the BI models did not contain an actual pair of anti - aircraft cannons , and some reports claim that BI - 4 was used for the live ammunition tests . The guns were never fired in any flight . The BI - 4 model was reportedly used as the template for the mass production of 30 to 50 BI - VS model aircraft by Andrey Moskalev ' s factory . Moskalev augmented the twin ShVAK guns with a load of ten thermite bombs . On March 27 , during a low - altitude test flight , Backchivandzhi pushed the aircraft ' s speed . After 78 seconds , the plane went into a 45 - degree dive and crashed into the ground , killing the beloved pilot . The accident put a halt to flight tests , and a lengthy investigation began . Eventually , after wind tunnel testing , it was determined that the BI - 1 lost control due to the effects of transonic velocity . Estimates of Backchivandzhi ' s final velocity range from 800 to 990 km / h , but the recording instruments were too damaged by the crash for a reliable measurement . March 27 is considered a black day in Soviet aviation history , also being the date that Yuri Gagarin died in a jet plane crash . In 1973 , Backchivadzhi was posthumously awarded Hero of the Soviet Union . Return to Moscow , Isaev ' s engine . In May 1943 , OKB - 293 returned from its evacuation and set up operation in Khimki , a suburb of Moscow . On May 18 , Bolkhovitinov wrote a detailed report " On Rocket Aircraft and Further Prospects " . He emphasized the need to study the dangerous regime of " shock stall " , and to safely transition through transonic speed and beyond . He proposed the goal of a new rocket plane capable of 2000 km / h . The next year , Bolkhovitinov had five more aircraft produced , BI - 5 through BI - 9 . In the Spring of 1944 , BI - 6 was fitted with a pair of Igor A . Merkulov ' s DM - 4 ramjet engines . It did not contain a rocket engine , so it was towed into the air . The pilot , Boris Kudrin , flew the BI - 6 three times , but was never able to get both ramjets to start at the same time . The plane was taken to TsAGI for further tests in the T - 101 wind tunnel . The DM - 4 auxiliary motor was also tested on the YaK - 7b fighter . With the loss of the D - 1 - A - 1100 engine , Isaev began designing a new engine . The RD - 1 was completed and tested in October 1944 . The general form of the engine was the same as Dushkin ' s , but with numerous improvements . Isaev fashioned the sections from 12Kh13 stainless chromium steel ( 13 % chromium , 0 . 12 % carbon content ) . The head had 85 swirling injectors arranged in a honeycomb pattern that promoted improved fuel - oxidizer mixture . It also used a more reliable electric arc starter instead of a glow plug . Isaev also improved the regenerative cooling , increasing the flow rate around the nozzle . BI - 7 was flown twice with the RD - 1 engine , on January 24 and March 9 , 1945 . Pallo reports there was an emergency with the landing gear during the January flight . In addition to the new engine , various changes were made to the plane ' s design : a larger rudder , smaller false keel , and different wing fillets . During the test flights , the pilot Boris Kudrin , noticed some tailfin flutter . On May 29 , the pilot M . K . Baykalov tested the BI - 7 in glider mode , without starting the engine , and the flutter was not detected . At this point , the plane was too corroded by nitric acid to fly again , and it was retired . To further investigate the flutter problem , BI - 5 was modified in the same fashion as BI - 7 ( but with no engine ) and tested in glider flights ; however , the problem was not reproduced . After BI - 6 was sent to TsAGI , BI - 9 was put into service as a replacement ( marked with a " 6 " on its tail ) . Flown by Boris Kudrin and M . A . Baikalov , it was used in glider tests with extra payload weight . The fate of BI - 8 is unknown . Powered flights . The BI was flown 12 times under power , seven times with Dushkin ' s D - 1 - A - 1100 engine , three times with the DM - 4 ramjets , and twice with Isaev ' s RD - 1 rocket engine .