Bisnovat 5
The airplane " 5" was built in only two copies experimental aircraft with rocket propulsion and swept wings.
History
The project began in the spring of 1945 under the direction of M. P. Bisnowat. The goal was the experimental investigation of the flight in the supersonic range, because to do so with no experience but just theories were, which should be checked. Lack of findings that may be encountered in transonic shock waves and other effects had eg crash the Soviet Bolchowitinow BI -1, but also of various X - planes of the United States out. By airplane " 5" should take advantage of the swept wing are examined. The project was developed concurrently with the later captured by the Soviet Union DFS 346 and the Douglas D- 558- II Skyrocket. Although all three projects were carried out independently of each other, there were many details to similar solutions and results.
The airplane " 5" was an all-metal mid-wing monoplane with a swept-wing zweiholmigen (45 ° sweep in 25% tread depth ). The airfoil was chosen as recommended by the TsAGI. At the root, there was a ZAGI 12045bis and P2 at the end of a (2M). The biggest design flaw of the German DFS 346 was avoided, because the DFS 346 had over the entire span of the same profile leading to abrupt flow separation on the entire wing and thus could lead to a complete loss of lift. Here, the lack of knowledge about swept wing also pointed to the German side. The " 5" were arranged around an early stall at the wing tip to prevent any airfoil top two boundary layer fences. The right wing was located at three cross-sections per a set of measuring bores to determine the pressure ratios. The body had an upright oval in cross section and a hull separation point, which allowed the assembly of the actuator and the fuel tank. In the forward fuselage there was a pressurized cabin with ejection seat. The canopy was designed hull compliant and non- towered over the hull. The ideal form of spindle could remain protected (as with the DFS 346 and the first embodiment of Douglas D- 558- II). In the rear fuselage airbrakes were fitted in the rear, a two-chamber liquid rocket engine RD- 2MSWF the designer LS Dushkin. At altitudes above 8000 m, the thrust was 19.6 kN, 15.8 kN at ground level. Fuel was kerosene, nitric acid and hydrogen peroxide. The fuel supply was designed for 2 minutes at maximum performance of both combustion chambers.
The hydraulic control was something completely new and had yet to some extras. Thus it was possible in loss of elevator effectiveness to control the aircraft by adjusting the entire horizontal tailplane. This was the pilot switch on the control stick. Further, the pilot could switch off the feedback control. This meant that he gets taught at the controls no longer control forces and allowed to use it in an emergency very high control forces.
The start should be made by a carrier aircraft. Therefore we reduced the suspension to a landing skid, the tail skid and reinforced edging strips to the wing tips. The carrier aircraft was a Pe-8, where the "5" was suspended under the right wing between the fuselage and the engine nacelle first. In order to test the " 5" models were built with autopilot and dropped from a Tu- 2 and tested. For the models Einkammerflüssigkeits a rocket engine U- 400-10 came with a thrust of 400 kp at 10 km altitude are used. With the models, many values were flown. How could, for example, the shape of the resistance curve to Mach 1.45 are included.
An unpowered test flight of the original should like the following take place: Coping by carrier aircraft in 7000-7500 m altitude, catch up swoop for driving, transition to horizontal flight with 2 to 3 g load factor, deceleration to stall and renewed nosedive. From an altitude of 1500 up to 2000 m, the program should be stopped and the flight home be commenced. A test flight with rocket propulsion should the " 5" to a speed of about 1200 km / h and at altitudes of 12 km to 13 km transport (Mach 1.13 ). Calculations showed, however, that much higher speeds and heights would be possible. This also coincides with the American Douglas D -558 -II, which was designed for Mach 1.4 and Mach 2.01 reached.
Test flights
Since two aircraft were built, they are often called as " 5-1 " and " 5-2 ".
The " 5-1 " was first flown by the test pilot A. Pakhomov K. on July 14, 1948 as a glider. There were problems with the separation of the engine from the aircraft carrier. The " 5-1 " was damaged and only managed a field landing, in which the machine suffered further damage. Problems also made the longitudinal control. After the repairing and remodeling of the ejector were two other non-powered flights in which the converted control also now worked perfectly. However, the aircraft showed an unfavorable ratio of transverse and rate stability. This was one of the causes of the disaster at the end of the third test flight. The plane arrived at the landing first with a wing on the ground, then with the other. Ultimately, it almost cracked and was largely destroyed. The pilot was uninjured, but a repair of the aircraft was no longer possible.
In January 1949, which was " 5-2 " completed. It differed in details from the " 5-1 ". The stretch and sweep of the vertical tail was increased to improve directional stability. At the wingtips the end curves were replaced by spring spurs on the recommendation of TsAGI.
The first flight of the " 5-2 " on 26 January 1949, Georgi Schijanow ended again with a field landing. However, this was also due to the unusual for the pilot aircraft and the short landing strips of the LII. The aircraft was damaged. During the repair, the aircraft was rebuilt. The landing skid was designed so that you could do without the tail skid. Space thus created for the installation of a false keel, which should improve the directional stability on the stern.
The next flight was smooth, but showed that the necessary relationship between lateral and directional stability could still not be reached. Normally one would face the problem of a change in the V- position of the sash. But that was not possible because the wings were inextricably connected to the fuselage. Therefore, it came to the installation of the " fins" on the wing outer edges. These had the same profile as the wing and were directed at an angle of 45 ° downward. With this design Georgi Schijanow graduated in June 1949, six more flights in which speeds of Mach 0.775 was achieved. The mass of the airplane at this time was 1710 kg. The aircraft convinced these flights and also the control proved. The plane was ready for a flight with own drive. This never occurred for unknown reasons, however.
Specifications
Literature sources
- " Skyrockets " with the red star - Publishing FLiEGERREVUE 1993