Tupolev Tu-504 Seaplane
The Tu-504 was designed based on the incomplete development of the Tu-85 bomber. Design work on this machine was conducted from 1950 to 1953 by the specialists of the Brigade of the OKB projects at plant No. 156, and also by TsAGI. In the design bureau, the work on the project was led by BM Kondorsky, also GA Cheremukhin and VA Sterlin worked on the project (in the future they became the leading aerodynamics of the Tupolev Design Bureau). The digital designation of project 504 was internal to the OKB and it was deciphered quite simply - this was the 4th project of the year 1950.
By the mid-1950s it was considered highly probable that the enemy simultaneously could disable a significant part of the airfields of Long-Range Aviation. OKB-156 and OKB-23 under the direction of GM Beriev, AN Tupolev and VM Myasishchev were to develop supersonic seaplane projects as an alternative to land planes. The Beriev and Myasishchev projects focused on strategic aircraft, but the Tupolev project took a different course.
The name of Tupolev is not commonly associated with seaplanes. But one of the activities of the team of A. Tupolev in the 1920-30s was the design of seaplanes for naval aviation. The works covered the construction of both float seaplanes - variants of land crafts KB, and the creation of flying boats. Floating seaplanes, in particular variants TB-1 and R-6 (TB-1P, MP-6), were produced serially and for many years successfully served both in the Air Force and in civil aviation. By seaplanes-flying boats KB prepared several original projects, the work on which, for various reasons, did not leave the stage of prototypes or small-scale production.
At the beginning of the 1930s, the Design Bureau released its first experienced long-distance reconnaissance aircraft, the middle-class flying boat ANT-8 (MDR-2), which was successfully tested. He was followed by work on a heavier flying boat ANT-27 (MDR-4, MTB-1). This machine was adopted for serial construction and for several years was in service with naval aviation. Simultaneously, the KB was working on heavy-duty flying boats: in 1929 the Air Force proposed a project for a large ANT-11 single-seater hydroplane (MTBT); in 1934, an experimental two-seater hydroplane ANT-22 (MK-1), which had no analogues in the world its constructive and layout solutions.
On the eve of World War II, the KB designed and tested a four-engine flying boat ANT-44 (MTB-2), flight-tactical data of which were at the level of the best analogous foreign models. However, the outbreak of the world war demanded the concentration of all forces on land planes of various classes and the work on the introduction of the ANT-44 series was canceled.
Following the front-line bombers, the design bureau started transferring long-range bombing aircraft to the reactive thrust, designed to inflict strategic strikes at European and Asian theaters of operations, as well as neutralizing naval activities and shipping of Western countries. To the creation of such a machine, which was supposed to have a range of piston Tu-4 and speed close to 1000 km / h, the KB approached, having completed the whole program of preliminary works.
Firstly, flying the first heavy aircraft in the USSR with a swept wing - an experimental bomber "82". Secondly, in the search for the most optimal layout and selection of the required mass-dimensional parameters, several preliminary projects of long-range jet bomber class aircraft (projects "86", "87", "494" and "495") worked. Together with the engine builders, KB developed the requirements, and then received from them a unique AM-3 engine, which at the beginning of the 50's became the absolute record holder in terms of thrust values.
In the early 50's, the design bureau began to search for supersonic heavy aircraft. The research went in three directions: the creation of a supersonic front bomber for replacement in the Il-28 formation, long-range for the replacement of the Tu-16 and intercontinental for the replacement of the Tu-95 and M-4.
Later on, the KB returned to the projects of seaplanes of various classes several times, but all these projects did not go beyond the stage of initial development.
The intercontinental strategic bombers developed in the Design Bureau (plane "85") had a combat range of 5000-6000 km, which was still not enough to deliver a guaranteed strike against USA, taking into account the anti-air defense, maneuvering on the route, etc. The problem could be solved by introducing refueling in flight.
However, the difficulty of refueling the aircraft in the air on the way back: the difficulty of accurately leaving the aircraft-bomber and tanker in the filling zone, taking into account the crew fatigue after a long flight and the combat mission, and the lack of appropriate navigation equipment, suggested the idea of ??domestic aviation specialists and military analysts to use for refueling submarine-tankers, previously deployed in the waters of the Pacific and Atlantic Oceans.
As the strike component of the system, it was suggested to use a flying boat designed using the main aggregates of the aircraft "85". During the design, the question arose of comparing the capabilities of the land and sea variants of the "85" aircraft. So in the early 1950s before the OKB was the task of developing a giant flying boat. This was the first work of the OKB on a seaplane after a fifteen-year break after the creation of ANT-44 (MTB-2).
To correctly evaluate the aerodynamic characteristics, the connections between the geometric shapes of the seaplane body were checked on models in the TsAGI T-102 wind tunnel, physical interpretations of these dependencies were found. Thus, for example, it was shown that the carrying capacity of the bottom of the boat (due to the cheekbones) is twice the normal fuselage, that the interference of the wing and the bottom is practically independent of the distance between them, that the resistance is independent of the angle of attack, that the shape is edited in the plan does not affect its aerodynamic resistance and that smoothing the cheekbones behind the editors significantly affects the reduction in resistance. These dependencies, along with the study of the requirements of hydrodynamics, together with TsAGI, developed a design of the hull, which met the requirements of both aerodynamics and hydrodynamics.
In July 1950, the OKB team of projects received the task to review the project of a flying boat on the basis of the aircraft "85". Preliminary design confirmed that the aircraft "85" with the ASh-2K engines came closest to all of these from land aircraft, which was chosen for further work as the base one. The calculations based on the hydrodynamic tests of the ANT-44 flying boat models and the foreign materials on aerodynamics and hydrodynamics of flying boats designed in the late 1930s and the 1940s showed that a flying boat with a wing and power units of the " 85 "can have the given ranges, mass and bomb load, but can not provide the given speed of flight, since this speed was only satisfied by the plane" 85 "with much better aerodynamics.
It would have a speed of 580 km / h over the target. With the ASH-2K engines and with the existing wing, the takeoff take-off mass could be equal to 104,000 kg, and the take-off run with take-off weight of 90,000 kg would be 2,300 m, with a mass of 100,000 kg - 4000 m, with the range could be brought up to 10,000 km. Two variants were worked out that differed in the scheme for installing wing floats: in the first variant floats, in a configuration that repeated the ANT-44 floats, were mounted on the wing consoles and were not removable, in the second variant the floats in flight turned in the span of the wing and occupied a place on the wing the ends of the wing.
During the work on the project "504" a large amount of work was done on various forms of the edited part of the fuselage, in its hydrodynamic and aerodynamic perfection. Subsequently, these developments TsAGI used in the design of flying boats Be-10 and Be-12. During the development of the "504" project, the projects of a flying boat with four TVD-1 engines and then TV-12 were proposed, while maintaining the original scheme.
Work on the project "504" ended in 1953, when already built and tested the experimental aircraft "Tu-95", the range of which should have been more than enough for a flight to the United States.
|wing span, m||56.0;|
|plane height, m ??||12,0|
|Flight mass, kg||90000|
|Engine power, hp||4 x 4500 hp|
|Bomb load, kg||6000|
|Rifle-cannon armament||10 x 23 mm|
|Maximum speed at an altitude of 10000 m, km / h||645|
|Range of flight with 6000 kg of bombs, km||8200|
|Join the GlobalSecurity.org mailing list|