anti, Strategy, air-to-ground
March 11, 1954 the Council of Ministers of the USSR issued a decree on the establishment of the aviation system missile K-20, which Tupolev OKB-156, designated a leading performer, were instructed to develop a carrier aircraft Tu-95K based on the Tu-95MA (nuclear carrier ammunition). The same document organization appointed by the developers of the complex components. They acted as the company already had experience working together on anti-ship missile "Comet". Guidance system of K-20 was instructed to develop a KB-1 Ministry of Medium Machine Building under the direction of M. Shabanov doodlebug X-20 - DB-155 Mikoyan (chief designer Mikhail Gurevich).
system requirements stipulated the possibility of destruction of major strategic targets at a range of 600 miles when flying at altitudes carrier to 12-13 km. Speed X-20 was supposed to be supersonic, at least 1700-2000 km / h, which outpaces the existing fighters. Dimension determined using rocket warhead agreed - a nuclear warhead with a mass with the necessary systems was approximately 4000 kg.
doing with reasonable conservatism and drawing on the experience of the "comet", the engineers chose the OKB-155 reliable THD. Using turbojet propulsion rocket simplified energy issues - accessory gearbox TRD provided work and electric hydraulic pumps. Based on the requirements for speed and estimations of mass-dimensional characteristics of the rocket thrust required of 10-11 tons and only suitable for engine thrust and dimension was AL-7F - newest THD, just practicing for the last fighter I-7U. However, this power plant and weighed under 1700 kg, and supersonic flight required the use of afterburner mode with the appropriate fuel, the stock of which to achieve estimated range would be about 4000 kg.
In developing the X-20 used the experience of designing and building OKB supersonic fighters (just as in the construction of the "Comet" reflects many solutions MiG-15). Doodlebug airplane built by the scheme with frontal air intake structurally borrowing many of the same features of the AND-7U.
fighter borrowed from a common layout geometry wing with a sweep of 55 °, and a supersonic profile. However, especially the X-20 as a single-mode aircraft not used for maneuvering and low speeds during takeoff and landing, have reduced the area of the wing and its chord, abandoning flaps and brake flaps. Due to the lack of landing modes specific wing load projectile was adjusted to 470 kg/m2 (one and a half times more than what the MiG-19), but at the request of this parameter range was chosen significantly less than the "near" and K-speed 10, where it was 640 kg/m2. To avoid reverse aileron faced by supersonic aircraft, especially at low rigidity lightweight construction wing missiles, ailerons placed closer to the root of the wing (this benefit is not hampered by the lack flaps), halved their deflection angles while increasing their size to save sufficient controllability roll.
Originally dimension tail respected conventional aircraft proportions, but because moderate maneuverability requirements (on the main modes of flight task was to preserve the stability of the rocket) in the final plumage significantly decreased, and the relative area of the horizontal tail was only 16% of the area of the wing, and vertical - 11.2% (compared to conventional aircraft in the 20-25%). Kiel thus shifted unusually close to the center of gravity of the rocket - already on its suspension layout considerations for media where its normal location prevented the fuselage tanks. To stabilize and control transients were sufficient small deflection angles elevator and stabilizer tselnopovorotnogo (ready to use it even when tests revealed the MiG-19).
scheme with frontal air intake not the best answer arrangement missiles, complicating the design of extended air channels, "eat" internal volumes and cause aerodynamic losses. However, it provides the smallest midsection, in addition to supersonic speeds such intake was then worked out enough and did not promise problems. Overall design and construction of X-20 steel practical compromise required and available to the designers.
This fully concerned and guidance systems - classical radio command control is not suitable due to a given horizon range - the signal was attenuated at a distance, the method was unreliable due to disruption of guidance failure command line and is vulnerable to interference effects. Besides, was it difficult to control the flight of the missile to the target. Radar vectoring using seeker, or active illumination target carrier at such distances was also ineffective, mainly due to insufficient visibility of the radar targets - many strategic locations, even of large size, not on the different radiocontrast background area, not to mention the that the set was outside the range of the radio horizon.
main combat missions distant aircraft were nuclear missile defeat enemy forces, its military-industrial and energy facilities, violation of state and military command and control, operational and strategic defeat reserves and transportation. Appropriate targets - military bases, airports, warehouses and control points were not only low contrast on the ground (except, perhaps, transport hubs and seaports), but is usually masked, making radar, thermal and other similar weapons guidance systems unsuitable . However, such objects had large size and were tied to the area, and their location is a landmark decision in combat missions, allowing to characterize them as "targets with known coordinates" (which, in turn, is the task of intelligence).
Implement fully autonomous guidance for such purposes using the onboard missile system prevented insufficient accuracy and reliability of the then national systems. The solution was to use a combined guidance system of aircraft projectile with an onboard programmable autopilot and radiometric equipment carrier.
Draft project Tu-95K was prepared for six months and signed by AN Tupolev October 26, 1954. In the autumn of 1955 after the military took over the coordination of the layout of the submarine. The aircraft received significant changes from baseline bomber: the bow placed a two-antenna radar equipment with individual fairings workplace navigator moved in the cockpit; gruzootsekah to accommodate fifteen-missile lengthened by almost half, equipping beamed holder DB-206, which in the semi-flush position X-20 was suspended. To reduce drag in flight along the route, the holder of the missile is in the retracted position and the air intake X-20 was covered by a semicircular fairing. Before starting the cowl turned, tidying up in the fuselage, the holder fell by 950 mm rocket engine was started and carried uncoupling. In flight, the rocket without gruzootsekah closed doors.
The increase resulted
gruzootsekah rebuild the fuel system, which somewhat diminished capacity, to launch the rocket engine, its warm and output mode in the fuselage tank installed an additional 500 kg of kerosene, the fuel system is connected to the X-20 highway with shutoff valves, overlapping front starting. For power equipment introduced additional more powerful transmitters in the electrical AC.
Placing heavy rocket fuselage caused considerable changes that have affected a number of security elements. Built experienced missile carried Kuibyshev aircraft factory number 18, where they were used in the two standing stocks TU-95 number 401 and 404. Alteration began March 1, 1955, just one year after the issuance of the job. It ended on October 31. The leader flown on January 1, 1956, in the summer and he was joined by a second car. They were held and factory testing of the complex, which took place in three stages with working the media itself, preparations for launch of its systems and commissioning complex control equipment and homing missiles. Factory tests Tu-95K ended January 24, 1957.
for flight testing of unmanned systems products used two serial MiG-19, refitted OKB-155 aircraft analogues CM-20 / I and CM-20/II. Their equipped nodes under suspension medium and a set of onboard equipment radio placed instead of one of the tanks and in the fairing under the fuselage. Analogues, similar in mass-dimensional and flight characteristics for the X-20, the first flight took off from the airport, and then took off on the Tu-95K and after the reset was performed using the flight management system K-20, practicing characteristic regimes. In these flights them flown by test pilots Amet-Khan Sultan and VG Pavlov. During 1957 aircraft made 27 flights analogs with self takeoff and 32 - with discharge from the media. With their help, was also investigated immunity control system, which at the site during the summer of 1958 Vladimirovka completed nine missions with simulated jamming. Total same pair of CM-20 has performed more than 150 flight test program K-20.
summer of 1957 began testing aircraft missiles X-20. They lasted from 6 June 1957 to 29 July 1958. Tests X-20 were satisfactory, with no significant defects in the system. However, there were claims to the range and accuracy: in the first start March 17, 1958 is not rocket started marching trajectory due to a fault and failure statoscope LDPE - the device can withstand a predetermined height has not been achieved and established range. In April next start has been made, and in July - two more, followed by a decision on the transfer of K-20 on state tests.
joint state tests began on 15 October 1958 and ended a year later, November 1, 1959. Within them performed 16 launches X-20, of which 11 have recognized to be valid, albeit with reservations on the accuracy reaches a predetermined. Defects were found in the work of the power plant and on-board equipment. And then at the height of the engine would not start, freezes at a height of up to -40 ° C. Normal kerosene in a supercooled state is not on fire, and for starting the aircraft is equipped with a tank feeding system start-up fuel - gasoline B-70, and the engine is equipped ignition. Increasing the stability margin, and finished the intake cone input device, extended air intake to the engine.
parallel was decided to replace the warhead's advanced new thermonuclear charge. Testing of nuclear warheads and its systems was carried out in 1957. The upgraded missile was designated the X-20M. By expenditure of X-20 of the first embodiment will not be accepted for service, the tests were continued on the new samples.
Testing Systems and Automation warhead demanded the implementation of several more test launches. X-20 launches were carried out under the influence of interference during the test also observed similarity combatant operating conditions. Despite a number of comments received positive evaluation reliability, ease of development and maintenance performance. Government decree on September 9, 1960 Aviation and Missile System K-20 was put into service. As stated above, pursuant to the same PSM from March 11, 1954 were working in parallel to create a missile-carrying variant myasischevskogo ZM-K-20. According to the Order of MAP from 31 December 1954 both carriers were required to have a single system of guidance and doodlebug X-20. Serious problem was the placement itself X-20 aircraft myasischevskom, labored very little clearance under the fuselage and cycling gear. The possibility of suspension missiles with a special hole in the parking lot, its installation on top of the fuselage with a crane and even mount a rocket under the cockpit of the aircraft in an inverted position, the keel down. Eventually found acceptable option suspension X-20 under the wing of a large and symmetrical placement of the PTB to maintain directional stability and balance. The rocket was attached to a rotary beam tilt in the starting position for departing from the carrier.
In January 1956, the State Commission considered Footprint layout. However, there remained a number of "bottlenecks", and in general, the decision conceded Tupolev, whose plane has already been put into test. Ultimately, the choice of the Air Force and the MAP was made in favor of the Tu-95K.
first serial Tu-95K was released in March 1958. Production aircraft factory number 18 lasted until 1962. In parallel there was a training version of the bombers Tu-95KU, who served for retraining and training of crews to work with the equipment. However, even at missile tests reveal its major drawback - the increase in weight of the aircraft and cumbersome suspension reduced range of almost 2,000 km, which is why the range of the complex began to give bomber. Even with the long-range missile launch, goals for the United States were at the limit of reach Tu-95K, and then, if their placement in the Far North and Far East.
Already during the test, July 2, 1958, came PSM, requires developers to take steps to improve the characteristics of the aircraft and the complex as a whole. OKB-156 and Air Force offered to improve the range due to refueling, pursuant to which SCI appeared on May 20, 1960, according to which the modified plane should have been submitted to the state tests already in the 1st quarter of 1961
Tu-95KD was equipped with a universal charging toplivopriemnika telescopic bar and electronic equipment "Inflow" to communicate with the tanker. Joint tests Tu-95KD ended January 30, 1962, after which the aircraft was put on production. According to this model, and converted a portion of previously issued Tu-95K. Subsequently, all the machines were modernized refueling type TU-95km with equipment more modern communication and navigation equipment. It includes a new flight navigation system "Path-1B" automatic navigation device ANB-1A and compass system COP-6D with Doppler Diss-1, which is easier to manage and have a positive impact on the accuracy characteristics.
flying bombs X-20 were collected pilot production OKB-155 and the factory number 256 in Dubna. Dubninskaya enterprise provided and a series of missile test. In connection with the transfer of the enterprise to issue new Kh-22, production of X-20M in 1960 transferred to the factory number 86 in Taganrog, seaplanes and engaged by this time-loaded main products. In 1963, the founders of the team of K-20 was awarded the Lenin Prize.
cruise missile Kh-20 (see the projection) had a classical scheme Planes monoplane with swept wings and tail surfaces. Glider-metal monocoque construction was made from aluminum alloys - in addition to D-16, widely used high-strength alloy V95 compressible. V95 has a specific strength of 1.5 times the normal dural, allowing you to create lightweight construction using extrusions and forgings, but was sensitive to stress concentrators and variable loads, demanded compliance technology to ensure the fatigue strength. In the play-loaded nodes and details used hromansilevye steel. Oversized load frames of the fuselage, beams and mountings units of a light magnesium alloy.
Wing area 25.14 m. 55 m and a sweep °, the line foci had a supersonic profile with a relative thickness of 6%. To reduce the complexity of manufacturing a number of airframe, including the wing and tail carried cast. At the same time it helped to improve the accuracy and purity aerodynamic contours. The decision was prompted employee NIAT ES Stebakova, together with the chief engineer of the plant YI Shukst engaged in the creation of casting technology thin panel by squeezing. The resulting thin-walled castings should Thermoprocessable, but their strong boxes with "leash" shapes and sizes. To prevent deformation of steel thermal load in furnace "chained" to the one-piece steel populated, getting ready finishing products with prescribed circuits that do not require machining.
empennage classical scheme with driving directions and turning whole-stabilizer, vertical tail area - 2.82 m2, horizontal - 4m2. For delivery keel and fender flares were shot, and final assembly factory team already in place. Small ventral fin, which served to enhance directional stability, for the convenience of transportation was also removable and fastened to the rocket is on the suspension.
Frontal air intake had a movable central cone extends automatically as the acceleration of the rocket. Round duct from the air intake had a complex shape, rounding warhead compartment at the bottom where it passed into a crescent-section and getting round again at the engine inlet. For the manufacture of air channel used volumetric models and a large number of stamping tooling. Originality different constructive solution voluminous compartment under the warhead, which demanded a three-meter cutout in the fuselage. Compartment, called "hold", reinforced by intermediate power frames, which at the upper belt mounting and dismounting warhead filmed and put in place after the equipment rocket charge.
Layout X-20 significantly blocked by placing the fuel tanks - a place for the required 4000kg of fuel had to look in the remaining unoccupied volumes. One of the tanks capacity 1390l located immediately before the warhead for the control system of the cone, the other in 2100l belted air channel for CU, three were placed near the engine. Total fuel (kerosene T-1 or TS-1) was 5090l.
main tank originally envisaged welded "keg" of sheet steel, but there are problems with corrosion of the internal cavities after etching, and steel replaced the light and welded construction tech alloy AMG-6. Large front tank per tonne of kerosene has a soft structure and carried out kerosinostoykoy rubber. Bulky steel punch glued layers of crude rubber, increasing its rubberized fabric-reinforcement, in aggregate pasted refueling nozzle and supplies. The entire assembly is placed in a vacuum boiler at high temperature vulcanization takes place. Of the finished tank through an incision in parts recovered punch zakleivaya seam and increased his webbing.
To access the power plant, in addition to operating hatches, served as the fuselage behind the wing connector.
X-20 was equipped with a special version of the engine korotkoresursnym AL-7FK, single-mode with a tapered nozzle simplified speed control and extended nozzle crown turbine blade which is made of heat-resistant alloy. Most of the X-20 flight was held at supersonic speed and afterburner thrust of engine 9200kgs, reported a rocket thrust at 0.82 static mode. Located on the bottom of the engine accessory gearbox, which is fed from the units onboard missile system.
autopilot blocks placed at the bottom of the fuselage behind the warhead near DH rocket. Located above the engine radio equipment, the receiving antenna which is in the ending of the keel, which housed the antenna and aircraft defendant range SOD-57M involved in the guidance system.
in a special compartment of the fuselage was mounted container spec-BCH (such placement received the name "ampoule"). Its units were placed in two sections - the actual combat with the nuclear charge with the system gain and thermonuclear instrument containing equipment automation with command detonation device that initiated the synchronous operation of electric detonators at a given ground contact or blowing air at a predetermined height above the target. Hermetic "ampoule" warhead equipped with means of temperature control, to maintain the required temperature and humidity to ensure the efficiency of the charge. Special-BCH also equipped with a system of protection and charging, which excludes the possibility of inadvertent activation and providing only undermine compliance with the established procedure.
Complex K-20 could be used in navigation and radar modes.
aircraft carrier output in design point and, after pre-launch operations, with the removal of up to 600 km from the target, the crew starts the X-20. Rocket with the on-afterburner engine and rudders depart from the locked carrier, graying at 300-400 m On command the autopilot at the 46th second rudders deflected to pitch, and the missile passed into the climb. With access to a given reference height of 15000 m to 221 seconds of software device transforms the X-20 in the horizontal cruising flight, and login control channel from radiometric station carrier, asking guidance on the course. Flight altitude stabilized statoscope. Plane remained on the combat course, by more than two-fold difference in speed with a rocket to the top of the command step guidance was 350-450 km away from the goal.
exit to the distance of 50 km to the target control is switched back on autopilot, after a specified time translated the X-20 in a dive at an angle of 60 °. Produced over the target air blasting warhead at a predetermined height. When you hit the specified targets, usually the group and area, air burst is more efficient and provides a significantly larger area of the lesion. At the same time undermining its power at low altitudes on the order of 500-1000 m led to the destruction of solid objects and ground shelters. The system ground pin served to undermine the backup.
possible mode of application was also X-20 with advanced radar destination search radar vehicle, to seize it and then starting. It was preferable to the accuracy and reliability (still with the objective immediately observed on the screen, and the operator can control the process of guidance), but lost on launch range as target detection radar provides only remove 450-470 km. In the final step guidance with the transition X-20 in standalone mode, the carrier turns away from combat course, not staying closer to 250-270 km from the target. Range of K-20 was 6800-7000 km with rocket launch with a 600-km boundary.
strategic objectives in the Americas, a large range of K-20 system allowed the use of its priority against other opponents - and multipurpose aircraft carrier battle groups in the ocean (AUG and AMH). In addition to their role as a major strike force on the marine and coastal theater, ship groups involved to ensure action missile submarines - a new and very dangerous threat, appeared on stage to mid 50s. Ships carried cover areas of their deployment in the ocean, and maneuvering AMG was one of the exit signs boats fighting positions.
in 1957-58. Tu-95K investigated the possibility of finding and destroying mobile naval forces. During the flight over the Barents Sea crews managed using radar to detect a group of ships from a distance of 400-450 km. Encouraging results led to the conclusion about the suitability of the complex to deal with the AUG. At the initiative of the Design Bureau and the Air Force in the summer of 1960 were organized launches X-20 ship goals.
American AUG portrayed two cruisers, five destroyers and two patrol boat of the Northern Fleet. To implement the environment group disperses into the sea, simulating ship order, began maneuvering the threat of a nuclear strike, occupying 22 km wide and 10 km in depth. Attack them had six Tu-95K.
goals difficult sea state, let glare or flickering screens radar tracking of pluck, and lead to manually target. Yet operators been isolated in groups individual targets. Launches were performed with heights of 10-12 km at a distance of 350-360 km from the ships. To avoid falling into the ships carrying the regular crew, the hardware missiles introduced an amendment to the 15 km flight goal. Only one of three starts in August 1960 the system has worked without any problems, the missile has sighted the target and was undermined with a deviation to the left 8.5 km flight and 4 km from the center of the ship orders. Another two start failed because of failure control lines, causing the rocket went off with the flight of 300 km and was undermined by radio command, and also because of the failure of the airborne radar.
In subsequent firings sparked criticism insufficient reliability of complex equipment. The fault of equipment defects aircraft and missiles were foiled two of three starts against naval targets, carried out in December 1960. Missiles and carrier system underwent refinements to improve reliability to an acceptable level. ;
Nevertheless, the experience was considered useful. Power CU gives hope for the sinking of the immediate objectives and kilometer blunders on other ships blast to incapacitate the crew, radar systems, communication and control, then completed the rout weakened grouping Tu-16 missile, submarine and naval ships.
Wing area, m2
Length without PVD, m
Fuselage diameter |
Weight starting |
Weight empty kg
Launch range, km
Height start |
M = 2
tests and operation
Operation K-20 in the Air Force combat units began in August 1959, when the first missile came in 1006-TBAP in Uzyn near Kiev. By year end, the Tu-95K 1226-received TBAP in Semipalatinsk, and then the 182nd Guards. TBAP in Mozdok. February 14, 1963 in Uzyn arrived first Tu-95km.
main goals of K-20 were considered the most important military and industrial facilities in the United States. These included nuclear airbase and storage of strategic aviation in the North at the Canadian border, in Texas, California and Louisiana in the south, missile bases and control centers in the central states, the cascade of energy facilities in the Great Lakes, nuclear centers and the Texas oil fields (at the time most of the oil and gas for the American economy given its own fields), as well as naval bases and ports on the coast of the United States and the islands of the Pacific and Atlantic oceans. Rates for most purposes ran on "Chkalovsky route" - the shortest path through the pole, or to the west coast of the Americas.
Many objects were at the limit of reach and crews regularly practiced and relocation activities with advanced airfields in the North, Far East and the Arctic, where ice rinks used (such teachings YES held at least twice a year). In flight refueling performed, mastered breakthrough low-altitude air defense, group and single shots. Crews thoroughly knew the future goals ahead of time studying the situation around, relief, radar and other landmarks, approaches and areas start.
constant combat duty shelves YES complicate the complexity of preparing X-20M. Required to fill the rocket fuel, special fluids, air and nitrogen systems to inspect and test the engine. If the start assumed tactical missiles without resetting, and it is often treated without installing ventral keel is mounted more than a hundred screws.
suspension itself under the X-20 aircraft required ruthless effort and skill. Trolley with three meters high product butt squeezed under the fuselage, causing a stirring blade propellers rotate and jewelry "guessing" keel clearance gruzootsekah missiles. Trolley "squat", allowing extra centimeters to win, but in this position permanently half an hour sat on the ground. Not once during seaming demolished antenna on top of the keel, which protect the steel using a special frame (with her in "touch" antenna remained intact, but used to crushes itself keel). For closing the X-20 effort required at least 15-20 people.
designated resource X-20 was determined by periods of storage, a touch under the carrier and the number of tactical launches. Repairs and improvements were made missiles ATM. At the same time shipping missiles repair often made by the carriers Tu-95K.
Working with nuclear missiles equipment took its rightful place in military training, but the shelves were always conducted using specific simulators and combat training products, equipped with all necessary systems, but without the nuclear charge, allowing you to work out all operations on preparation and application of special- warhead.
launches X-20M manned training warheads with explosive charge, make a noticeable explosion and "mark" at the crash site, allows you to judge the accuracy of hitting the target. In the course of combat training from January to October 1962 the crews of Tu-95K made 19 launches X-20M, of which 15 were found to be successful. At the time of adopting the K-20 system was quite effective. According to the then estimate the probability of intercepting cruise missile forces air defense fighters did not exceed 0.02 ... 0.05% is confirmed and exercises with the launch of the real X-20 passing through the object air defense zone on one of the polygons. Even after its detection radar failed to implement anti-aircraft missiles guidance and altitude supersonic interceptor goal - to those in the forward hemisphere were ineffective, and in pursuit overtake speed rocket was not possible.
However, after a few years the possibility of K-20 appeared to be insufficient. Primarily, this was due to the increasing levels of air defense missile systems saturates zonal defense with long range and high altitude and supersonic fighters, capable of intercepting aircraft and missiles, and missile themselves on remote frontiers to 1000-1200 km. Objectives against strategic objectives retreated to intercontinental ballistic missiles that looked then the ultimate weapon. In December 1959 the Strategic Missile Forces were formed, which according to the Order of the USSR Ministry of Defense December 31, 1959 and the Air Force General Staff directive of the former 18th, 48th and 50th were transferred to BA YES missile parts, connection management and two armies. As parts of the Strategic Missile Forces posing on alert them began to leave many problems YES.
were at the Air Force ranks shelves with K-20 system has increasingly focused on the tasks at sea - the defeat of naval bases and the hunt for AUG. Ensuring their implementation, missile crews also involved in conducting reconnaissance at sea, working in tandem with the Tu-95MR reconnaissance. During the operation of the complex has been reduced preparation time and labor. Launches against naval targets performed in the Caspian Sea, where a polygon with appropriate investigative telemetry and control equipment provides the flight of missiles (if necessary, in case of failure and exit from the path - their break-up). Have any - once in 1983, after a decade of operation of the complex, at the tactical crew error led to start involuntary discharge of missiles. She lost her suspension with the engine running and caught up with the plane hit him in the fuselage. The crew successfully got home the damaged plane and X-20M crashed into the sea, where it is then long and unsuccessfully searched for the sailors of the Caspian Flotilla.
complex as life grew, reaching an acceptable level. At last firings conducted in 1006th TBAP in 1987, dozens of rockets let loose all worked normally, hitting the target conditional on the range. However, it was the farewell chord - the combat effectiveness of K-20, according to the requirements established in 1954, looked very comforting, and the chances of performing a real combat mission in a modern air defense systems equipped with early warning AWACS airborne command post, the latest SAMs and interceptors (a deck "Tomcat" missile "Phoenix" have appeared in response to the threat of Soviet missiles) - absolutely untenable.
Nevertheless the writing off of Tu-95K in no hurry - long distant machines with air-launched missiles was not a substitute. The focus was on the development of other components of the nuclear triad, and in establishing strategic aircraft and missile systems for their qualitative changes occurred only in the early 80s, when weapons were received long-range cruise missiles X-55. Part of the Tu-95km, passing refurbishment as a modern complex K-22 remained in service. Continued to be enrolled in the Air Force and the former Tu-95K - the autumn of 1990 a dozen of these machines were in Ukrainian, another remained in Uzyn. These aircraft went scrapped only after the signing of the Strategic Arms Reduction Treaty START-1 in 1991. Thus, the life of K-20 in the Air Force was more than 30 years.