The TU-85 was an intercontinental strategic bomber prototype. Two machines were built. The first flight was 09 January 1951. In the course of tests intercontinental flight range was achieved with bomb payload of five tones. The aircraft was not transferred to serial production because of switch of strategic aviation to turbojet and turbo-prop engines.
The adaptation of the Tu-4 bomber could not solve the main task at the beginning of the great confrontation of the United States and the Soviet Union — the delivery of nuclear weapons across the ocean. Not very much contributed to the equipment of the Tu-4 in-flight refueling system. Teh Soviet Union needed something new, and it is not long in coming.
Work on the future 85 aircraft (Tu-85), began as early as 1948, before receiving an official assignment for an aircraft of this class from the Air Force. The Tu-85 was out of date, without having had time to be born, but the alternative was not because there was a highly economical and powerful big thrust turbojet engine. In this situation, the conclusion was one — to continue work on the TU-85.
It should be noted that the United States in the early postwar years created two strategic bombers — The B-36 and B-50. The first of them with a take-off weight of 181 tons could fly 16000 km without landing, and the second could fly 12000 km [of course, with no bombs]. In 1949, the two aircraft were in service with the US Air Forces, and Soviet aircraft of similar purpose only started to develop.
On 16 November 1949 the Decree of the Council of Ministers directed establishment of the aircraft "85" with ASH-2 k or m-253K engines. OKB-156, which was led by A.N. Tupolev, was to build an aricraft that coudl drop atomic bombs on the foreign enemy and eventual return home, flying without landing over 12,000 km. Less than one and a half years passed from the release of the Government document to the first flight. Creation of the Shvetsov ASH-2K engines went badly behind schedule, and the first machine installed Dobrynin M-253K designs, subsequently received the designation VD-4k.
To provide required range, Tu-85 had a new high aspect ratio (11.4) wing. Thick wing skin (10mm in the roots) allowed to save much weight on wing structure. Wing was much lighter than on Tu-4 and Tu-80. Fuselage, tailplane, avionics, defence vere similar to those of the predecessors. Aircraft had electric de-icing system installed on wing and tail leading edges, engine cowling and cockpits glazing. Propeller blades had liquid de-icing system.
Tu-85/1 (first prototype) could accommodate bombs up to 9000kg each (high explosive FAB-9000). For special long range missions crew could be increased to 16. During trials aircraft radio-electronic equipment was gradually upgraded to accommodate the most recent system. 59 flights were performed (142h16min in the air). This scaled-up Tu-80 with intercontinental range was powered by ASh-2 - the most powerful piston engines built in the USSR. This engine was not ready in time, and the backup VD-4K was installed. Trials program took a long time to fulfill, but no serious complications were encountered. Most troubling system was new panoramic radar station 'Rubidij-M' (sub-variant 'Rubidij-M-85'). But during trials it was brought almost to perfection and under designation 'Rubidij-MM' served with number of aircraft (Tu-16, Tu-95, Tu-104, Tu-114, M-4).
By the beginning of 1950s planes had already broken the sound barrier, but the heavy bombers still had cheap piston engines. This factor contributed to the preservation of the classical layout of the aircraft with a straight wing.
By mid-1951, Stalin had accepted the proposal of A.N. Tupolev on the Tu-95 plane, and the preliminary design for the new plan had begun. Accordingly, the attitude towards the "85th" in the top echelons of the MAP leadership was changing. All work on the testing and finishing of the two experimental aircraft ceased, preparation for serial production at factories No. 18 in Kuibyshev, No. 22 in Kazan and No. 23 in Moscow was curtailed. Both experiemental aircraft continued to fly in the MAP system, carrying out various flight test programs related to new equipment systems and with the general problems of creating heavy aircraft of this class, until the resources and reserves of VD-4K engines and the glider resources were exhausted. The first plane to write off was "85/1", and in July 1958 year and "85/2" according to the MAP order were handed over to scrap metal. Thus ended the five-year epic of the creation of the first and last domestic piston intercontinental strategic bomber.
Such a finale was in many ways quite natural. In the West: in the United States and in the United Kingdom, the design and construction of long-range and ultra-long-range strategic bombers with jet engines, the speed of which was approaching 950-1000 km / h and designed for a flight range of 6,000-12,000 km, was in full swing at the end of the 1940s. Against the backdrop of these projects, aircraft "85" looked obsolete even before its first flight.
The doubts about the ability of the '85th' to break through the modern air defense system, which by the early 1950s was already sufficiently saturated with near-sound jet all-weather interceptors, raised doubts. In addition, in the foreseeable future air defense of the leading Western countries were to receive supersonic fighter-interceptors with guided missiles and ground-based SAM complexes, the appearance of which sharply reduced the chances of a breakthrough to the goal of "85th". Therefore, the only correct decision is made not to dissipate forces on a successful but quickly morally obsolete piston plane, and concentrate all resources on new strategic intercontinental jet aircraft Tu-95 and M-4, which were supposed to be at the level of the best western developments.
The Tu-85 performance was very good for the late 1940s, but at the time new jet engines entered the arena, and speed of 660km/h became insufficient for bombers. Straight wing had to give way to swept one. The Tu-85 became an ultimate development of straight-wing heavy bomber with piston engines. Both built aircraft were used as a test until 1958, when airframe and engine resources were exhausted.
Work on "85" was not a waste of time, it was possible to clearly articulate and test the concept of an intercontinental strategic aircraft, to work out many elements for future heavy-duty heavy vehicles. In particular, the layout of the fuselage of the aircraft "85" with some adjustments due to the use of a swept wing (a single capacious cargo compartment), moved to Tu-95 . The composition of the Tu-95 equipment in many respects corresponded to his younger brother. Thus, the plane "85" laying the road Tu-95 , remained in the history of domestic and world aviation as the last heavy bomber with piston engines.
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