BI-1- First Soviet
Experimental, the first interceptor fighter with the LRE - liquid-jet (rocket) engine.
The designers of the BI aircraft are the engineers Alexander Yakovlevich Bereznyak and Alexey Mikhailovich Isaev - the staff of the OKB VF Bolkhovitinova. Bereznyak was the head of the brigade of mechanisms, Isaev - the engines. In the early spring of 1941, on their own initiative, they began the development of a draft design of a fighter of a new type - from the LRE, which promised the speed of 800 km / h and more.
In 1940, they visited the Jet Research Institute, where they met with engine designer Leonid Stepanovich Dushkin, who led the work on the LRE for the launch accelerator of the 302 fighter jet, then created at the institute.BIB in Monino
Already at the stage of preliminary design, they managed to solve a number of technical problems. The aircraft of A.Ya. Bereznyak and A.M. Isaev was originally designed for an engine with a 1400 kgf engine and with a turbo pump fuel supply to the combustion chamber, but then with the aim of reducing the time to build the aircraft, the turbopump fuel supply was replaced with more complicated a simpler and more crowded supply using air compressed to 145-148 atm from onboard cylinders with a capacity of 115 l. Due to this, it was supposed to reduce the size of the car, to improve its acceleration characteristics. This version of the aircraft with the engine D-1A became the main and received the designation "BI"; it was carried out according to the scheme of a single-carrying low-carrying low plan, which was usual at that time, of a mainly wooden structure.
Since the beginning of the war, they proposed Bolkhovitinov to submit a draft decree. A letter was sent from the RNII and the plant, which was signed by 7 participants, including the aircraft designers Bereznyak and Isaev, the engine designer Dushkin, the plant director Bolkhovitinov and the chief engineer of the institute Kostikov. The letter was sent to 9 on July 1941, and soon everyone was summoned to the Kremlin. The proposal was approved, adopted, A.I. Shakhurin and A.S. Yakovlev was drafted a draft resolution, which was approved a few days later (in August).
By a GKO decree signed by Stalin, the Bolkhovitinov Design Bureau was charged as soon as possible (35 days, instead of three months, as A.Ya. Bereznyak and AMIsaev wanted) to create an interceptor fighter with LRE, and the Scientific Research Institute-3 headed by A. G. Kostikov - RDA-1-1100 engine for this aircraft. On its basis there was an updated order by the NKAP.
The task of the Bolkhovitinov Design Bureau was to create fuel tanks and fuel supply systems for the liquid propellant rocket according to the principle hydraulic diagram of the Scientific Research Institute-3, and the task of the Dushkin Design Bureau (as part of the Scientific Research Institute-3) was to provide a variable mode of engine operation from 400 to 1100 kg of thrust with repeated launch. .
All the Bolkhovitinov Design Bureau was declared “in a barracks state”; they worked a month and ten days without leaving the factory. By September 1, the first copy of the aircraft was sent for testing to the NCAP. The aircraft was built almost without detailed working drawings, drawing in nature on its plywood parts, on plasmas. This was facilitated by the small size of the aircraft.
At the airport, first of all, jogging and approaching in tow were started, and the power plant was still being worked out. There were a lot of novelties and difficulties here, especially with nitric acid, which ate away tanks and wiring. A number of safety measures were required because of the harmfulness even of nitric acid vapors to humans, there were cases of burns. But with this managed more or less to cope.
The lack of time forced the engine to work out right away according to the aircraft scheme on the stand at the Bolkhovitinov design bureau, bypassing the autonomous engine test phase. These tests began as early as September 1941. Basically brought reliability of the engine start system.
At the request of the deputy people's commissar aviation industry pilot aircraft A.S. Yakovleva, the glider of the aircraft "BI" was prepared for research in full-scale wind tunnel TsAGI. The “BI” purges were carried out under the direction of G.S.Byushgens and A.L. Immediately after the completion of aerodynamic research, flight tests of the BI aircraft began in the glider version in tow behind the Pe-2 aircraft. Pilot Boris Nikolayevich Kudrin in 15 flights took off all the basic flight characteristics of the BI at low speeds. Tests have confirmed that all aerodynamic data of the aircraft, stability and controllability characteristics correspond to the calculated ones. Before evacuation, more could not be done.
October 16 The 1941 management decided to evacuate the design bureau and the Bolkhovitinov plant to the Urals. The next day, the stand was dismantled, all the equipment and documentation were sent to Sverdlovsk (Yekaterinburg). There in the 20-s of October were evacuated NII-3, together with the Dushkin Design Bureau.
After relocating to the Urals, work on the creation of a BI aircraft continued in December 1941 in the small village of Bilimbay (60 km from Ekaterinburg). The design bureau and the Bolkhovitinov plant were assigned the territory of a time-destroyed casting plant, where restoration work was carried out in extremely difficult conditions and in a short time. To continue the development of the aircraft propulsion system on the shore of the reservoir adjacent to the plant, on a former dam, a plywood lintel was built, in which the cradle stand was placed. From RNII, Pallo led the tests, and from the Design Bureau Roslyakov.
Instead of the sick test pilot B.N. Kudrin, the Air Force Command sent Captain Grigory Yakovlevich Bahchivandzhi. B-2
20 February 1942 of the year when starting the engine on a test bench, despite the competent actions of Bakhchivandzhi, an explosion occurred. A stream of nitric acid under pressure sprayed Arvid Pallo’s face and clothes. During the explosion, the engine head fell off the mounts, flew between the tanks of nitric acid, hit the pilot's armored seat and tore off the mounting bolts. Bahchivandzhi hit his head on the instrument board.
In March, 1942, the stand was restored, changes were made to the power supply system of the LRE. On the flight copy of the engine conducted control hydraulic and 14 fire tests, of which the final 3 held G.Ya.Bakhchivandzhi. 25 April the plane was transferred from Bilimbaya to Koltsovo (NII VVS). April 30 conducted 2 control engine start (the first - Pallo, the second - Bahchivandzhi). Work began on the preparation of the flight.
For the first flight of the “BI” fighter (sometimes designated as BI-1), a State Commission was created under the chairmanship of V.S. Pyshnova. The commission also included V.F. Bolkhovitinov, the head of the Air Force Scientific Research Institute, Pyotr I. Fedorov, the leading engineer on the BI plane from the Scientific Research Institute of the Air Force, Mikhail I. Tarakanovsky, and the leading engine engineer of A. Palo. The test pilot of the Air Force Research Institute G.Ya.Bakhchivandzhi was appointed the leading pilot.
The first flight on the BI fighter pilot G.Ya.Bakhchivandzhi performed 15 on May 1942. The take-off mass of the aircraft in the first flight was limited to 1300kg, and the engine was adjusted to thrust 800 kgf. The flight continued 3 min 9 with. Recorders recorded the maximum altitude 840 m, speed 400 km / h, rate of climb - 23 m / s. In the post-flight report, the test pilot noted that the flight on the BI plane was exceptionally pleasant compared to the usual types of aircraft: there is no propeller and engine in front of the pilot, no noise is heard, the exhaust gases do not enter the cockpit; the pilot, sitting in the front of the aircraft, has a full view of the front hemisphere and a significantly better rear hemisphere than on an ordinary plane; the location of instruments and control levers is good, their visibility is good, the cabin is not cluttered; in terms of ease of operation, the aircraft is superior to its modern fighters.
According to the State Commission, “The take-off and flight of the BI-1 aircraft with a rocket engine, first used as the main engine of the aircraft, proved the possibility of practical flight on a new principle, which opens up a new direction for the development of aviation.” This flight was the world's first flight interceptor fighter with the LRE, designed to perform tasks inherent in this class of aircraft, and appropriately armed. Abroad, by May 1942, only experimental aircraft with liquid-propellant rocket engines flew (Heinkel 176 and DFS 194 - the prototype of the Messerschmitt rocket fighter 163В, Gloster G.40 (England)).
In connection with the wear of the airframe of the first prototype (mainly from exposure to vapors of nitric acid), the subsequent flight tests of the BI aircraft were carried out on the second (BI-2) and the third prototype aircraft, differing from the first only by the presence of the ski landing gear. At the same time, it was decided to start building a small series of BI-BC aircraft for their military tests. The armament differed from the prototype BI-VS aircraft: in addition to the two guns under the fuselage, along the longitudinal axis of the aircraft, a bomb cassette was installed in front of the pilot’s cabin, closed with a fairing. The cassette housed ten small bombs weighing 2,5 kg, possessing a large explosive force. It was assumed that these bombs would be dropped over the bombers going into battle formation and hit them with a shock wave and fragments.
The second flight of the prototype BI-2 was held on 10 on January 1943. In a short time, four flights were performed on it: three by pilot G.Ya. Bahchivandzhi and one (January 12) test pilot KA Gruzdev. In these flights, the highest BI flight performance was recorded - maximum speed up to 675 km / h (estimated 1020 km / h at 10 000 m), vertical rate of climb 82 m / s, flight height 4000 m, flight time 6 min 22 with, the duration of the engine 84 with.
BI tests
In flight Gruzdeva with the release of the landing gear before landing one ski broke, but he safely landed the plane. In the memoirs of A.V. Pallo there is a colorful statement by Gruzdev after the flight to the BI: “And quickly, and terribly, and very behind. How the hell on a broomstick.
Flight to BI was difficult and not only from habit. It was possible to sit on it only after the development of fuel, it was unpleasant to have close proximity to nitric acid under high pressure, sometimes breaking out through the wiring joints, and even through the walls of pipes and tanks. This damage had to be repaired all the time, which greatly delayed flights that continued throughout the winter of 1942-1943.
The sixth and seventh flights were performed by G.Ya. Bakhchivandzhi on the third experimental aircraft (BI-3). The task for the pilot on the seventh flight, which took place on 27 in March of 1943 g, provided for bringing the speed of horizontal flight of the aircraft to 750 - 800 km / h on the instrument at an altitude of 2000 m. According to observations from the ground, the seventh flight, up to the end of the engine's work on 78 second , proceeded normally. After the end of the engine operation, the plane, which was in horizontal flight, lowered its nose, entered a dive and hit the ground at an angle of about 50 °. The commission investigating the circumstances of the catastrophe was not able to establish the real reasons for the transition to the dive of the BI plane. But in her conclusion she noted that the phenomena occurring at flight speeds of the order of 800-1000 km / h have not yet been studied. According to the commission, new factors could appear at these speeds, affecting the controllability, stability and load on the controls, which differed from the ideas adopted at that time and, therefore, remained unaccounted for.
In 1943, a high-speed wind tunnel T-106 TsAGI was put into operation. It immediately began to conduct extensive studies of models of aircraft and their elements at high subsonic speeds. The model of the BI was also tested to identify the causes of the disaster. According to the test results, it became clear that “BI” crashed due to the unaccounted features of the flow of a straight wing and tail assembly at transonic speeds that were unaccounted for and the ensuing phenomenon of delaying the plane into a dive, which the pilot could not overcome.
After the death of G.Ya. Bakhchivandzhi, the unfinished 30 - 40 of the BI-BC planes were destroyed, but work on this topic continued for some time. In order to study the possibility of increasing the duration of the flight of a “BI” type fighter-interceptor fighter that made up all 2 mines in 1943-1944. A modification of this aircraft with direct-flow jet engines at the ends of the wing was considered. On the sixth copy (BI-6) installed 2 ramjet. The plane was tested in the natural wind tunnel TsAGI T-101 in the spring of 1944, but it didn’t go further than the tube experiments. There was an attempt - incomplete - on one of the airplanes to make the cabin airtight by pasting all the seams with rubber strips.
In January, 1945, on returning to Moscow, on a BI plane with a ski landing gear and AM Isayev, RD-1 engine, a development of the D-1-1100 engine, the pilot B.N. Kudrin performed two flights. In one of these flights, with the take-off mass of the 1800kg aircraft and the 587 km / h speed, the “BI” vertical speed at the ground was 87 m / s. When flying BI-7, which differed from the rest of BI with the shape of the wing covering and the presence of the fairing of the arc launcher on the engine hoods, vibration and shaking of the tail plumage occurred. To find out the causes of these phenomena, by analogy with the BI-7 layout, the BI-5 and BI-6 were modified. In March - April 1945, their flight tests were carried out in a glider version (i.e., without the inclusion of the LRE). The B-25J bomber was used as a tugboat. BI-5 was tested with a ski chassis, and BI-6 - with a conventional wheel. No shaking or vibration was detected on them. Apparently, these flights were the last for the BI fighters, as soon the work on this subject turned off. For various tests, 9 of BI aircraft was built.
It became clear that the BI plane as a fighter could not be accepted due to the excessively short duration of the flight, which was not covered by a one and a half overweight. The BI aircraft served to accumulate experience in this kind of work - in other fighter projects with LRE and in LRE installations on piston aircraft as temporary flight accelerators.
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