R-1 Prototype Hydroplane
At the end of the Second World War it was absolutely clear that the era of battle ships finally ended and the new queen of the seas had become the aircraft carrier. Soviet fleet in this category of equipment and vessels, not war destroyed the industry has not been able to in the foreseeable future to build such a vessel. Because it was necessary to ensure the exploration of the sea and to perform some tasks that normally meet airplanes from the aircraft carrier was needed to find another solution.
GM design office Beriev, as the single source in the Soviet Union, had extensive experience in the construction of hydroplanes. It was behind the construction of various types, for example, KOR-1 to 4, MBR-2, MDR-5 and worked on the design of two flying boat Be-6 in the NATO code "Madge". After the Second World War there was available from the practical experience of the first operation of jet engines, the reliability and performance, meanwhile, increased considerably. Specialists from Berjevovy design office began an interest in their use to propel flying boats because they offer the possibility to significantly increase their flight performance.
At that time, on the other side of the ocean jet fighters FH-1 Phantom and F9F Panther were entering into service. This led the Supreme Commander of the Air E.N.Preobrazensky and the Supreme Commander of VMF N.G.Kuznetsov to support the efforts of designers, so in May 1947 the Beriev design office OKB-49 initiated work on the proposal first Russian jet flying boat. On June 12 1948, the government regulation c.2061-803 "Project R", which stipulates specific requirements: The aircraft had to be able to survey the bombing and so should reach the speed of their fighters opponents.
It was not easy work, but the difficulties that followed probably outdid the worst expectations. The biggest problem was the concept of aero and hydrodynamic hull, which had to move around double speed than had been usual. Mainly it was not clear if the airplane for secession from the classical level sufficient degree created at the bottom of the hull, or whether it will be necessary to propose a special design. In all cases the semi-paning method used air on the bottom of the hull, which should act as a separator. The air should be extracted using the shape of the airplane fuselage.
Since the Soviet Union lacked of suitable small jet engines and the lack of time for the construction of similar demonstrator followed the Soviets method of trial-and-error on the first prototype. Government tests to be launched in December 1949, but the OKB was fully utilized with the work on the piston Be-6 was the deadline closed. Yet they managed to build a model that could be presented to members of the VMF. New government regulations c.2747-974 10 June 1950 moved the date of opening of government tests for the year 1951. At the same time, it was decided to confirm the Rolls-Royce "Nene" engines, and change the original 20 mm cannon to a new 23 mm cannons. The new model was finished on 24 March 1951. VMF leaders insisted on the extension of options for other types of equipment of air bombing and demanded the possibility to carry two maritime mines AMD-500.
Seaplane R-1 received the free-carrying trapezoidal wing of the "seagull" scheme with a span of 20 m and an area of ??58 sq. Km. m. The basis of the power set of the wing was the caissons, on which the ribs and the working skins were mounted. The wing center wing had a larger transverse V than the console and was paired with them at an angle. The wing received slotted flaps of TsAGI type, as well as slot ailerons with trim tabs, spring servo compensators, weight balancing and aerodynamic compensation. Near the wing tips there were nodes of fastening floats, cleaned in flight. After take-off, the racks of floats should have been rotated 90 ° outwards, as a result of which the floats "turned" into wingtips.
The tail tail of the P-1 seaplane consisted of a keel and a 6.6 m stabilizer mounted on it. At the rear edge of the stabilizer and the keel, there were rudders of height and direction with trim tabs, weight balancing and aerodynamic compensation. In addition, the rudder of the direction was equipped with a spring servo-compensator.
In October 1951 the first test specimen was ready, which was the designation R-1. The factory test pilot IMSuchomlin launched running tests. Everything seemed fine until the airplane was the first to get into the air. Normally, such a decision comes at a time when the airplane successfully passed the tests running at 70% of take-off speed. When the airplane reached 80% of take-off speed, which was about 165 km / h, there appeared severe longitudinal vibrations. Further tests were relatively adventurous, because the airplane did not have sufficient longitudinal stability in the regime of sliding on water. The designers had met with virtually the first time phenomenon, which is known as the threshold of hydrodynamic stability. There had to help experts from TSAGI who actually after a long series of measurements and reconstructions to find an appropriate solution. In April 1946 yet more running tests and other structural adjustments had been implemented before they managed to get the stability issues resolved satisfactorily.
Finally, on May 29 1952 the airplane slid steadily on the surface speed of 196 km / h, so the next day came the first Russian jet seaplane flight of 23 minutes. The continued flight tests were not without problems. At speeds above 350 km / h, the aircraft shook and the landed like a "frog". At a speed of 190 km / h airplane went wild a few times (to a height of 4 meters) from the surface, and the device in the nose of the airplane measured 10.6 G! Although far from being able to solve all the problems, the work on the project halted.
Experimental flights were restored on June 18 in 1953 and the end of the year carried out 215 test airplane taxi and 28 takeoffs. Throughout the period of intensive work to remedy these deficiencies. Finally, it was in the construction of the airplane made 26 major changes that should improve its aerodynamic and hydrodynamic characteristics. Among other adjustments to the height and distance degrees at the bottom of the hull from the bow, adjustments in the wings, change direction and aerodynamic transition stabilizer, the introduction of spring servo-compensators for sufficient supply of air into the drainage system had to be on the back of the airplane created náporový special traps, which opened in the sliding on the surface, etc.
Finally they managed to successfully remove the vibration, which emerged at speeds between 350-710 km / h, even more to improve the longitudinal stability to sliding on the surface, during the start of the airplane swimmingly odlepoval the level of the landing and disappeared dangerous link. The airplane can be operated until the wave height 0.6 m, corresponding in terms of seafarers, sea state 2. In such conditions, the take-off lasted 40-45 seconds. In the normal take-off weight of the airplane vzlétal at a speed of 210 km / h. In the nominal engine speed was in horizontal flight speed of 740 km / h at an altitude of 7000 meters, at maximum speed to 800 km / h. Landing speed depend on the weight of the remaining fuel and fluctuated around 180 190 km / h. The behavior of the aircraft on water, especially in a side wind greatly improve the tail rudder of the hull. Highly placed engines and the PDR have been protected from water fragment during take-off and landing.
Minister of the Aviation Industry M.V.Khrunichev even proposed to cancel the project and transform the Beriev design office (which is tantamount to de facto dissolution). After wrangling with the minister of defense industry D.F.Ustinov and Chief Air VMS E.N.Preobrazensky, whose influence had been increased, on Oct. 8 1953 government regulation c.2622-1105 was issued which directed commencment of work on the flying boat "M", the future Be-10. The single prototype R-1 was transformed into a flying laboratory for testing aero and hydrodynamics hull at high speeds.
Tests of the R-1 continued until February 1956, when test pilot M. hairpin crashed on landing in shallow water damaging the bottom of the airplane. The airplane has been repaired and series production was not planned. Invaluable experience to designers received can be used in the construction of flying boat Be 10, which, although it was a new type, shape and form of conceptual experiments with the R-1 prototype.
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