When creating almost any plane is always a desire to expand its functionality. So, the fighter may eventually turn into a fighter-bomber, a passenger airliner into a cargo and training aircraft in the attack. Was no exception and loitering interceptor Yak-25. Large volume of the fuselage occupied by the radar gun, allowed to place it in the bow of the Navigator, and if the “press the” fuel tanks, it is possible for the cockpit to make a good cargo Bay for reconnaissance and bombing armament. So interceptor “120” became the reconnaissance Yak-25P bomber “125B”. But time passed, and the military needed a modern front-line supersonic car — the interceptor and scout. The basis for their development was the decision of the Council of Ministers of the USSR № 616-381 of March 30, 1955
The first of them received the OKB designation of “121” and in the series — Yak-27. Second — scout-fighter “122”, the future Yak-27R. They had a common airframe and were calculated under the RD-9.
The reconnaissance plane Yak-27R in the exposition of the Monino air force Museum.
Loitering fighter
According to a government document, the interceptor, developed on the basis of the Yak-25M, was to reach a maximum speed of 1300 km/h at an altitude of 10 000 m, to get this high for 2.5 minutes, have a practical ceiling 16 000 — 17 000 m and fly at a distance up to 2000 km, while maintaining navigational reserve of fuel. The aircraft was required to install two guns caliber 37 mm, with a total capacity of 200 rounds, and 24 unguided rockets (NAR) the ARS-57 or two turbojet projectile TRS-190. In December 1955 the car you have to present at a joint with the customer of testing.
To achieve such performance was possible only by increasing the thrust and reducing drag coefficient. Since the main component of drag at supersonic speeds is a wave, then reduce it by increasing the sweep of the wing or decreasing its relative thickness. In OKB-115 new wing was designed in a hurry, without the necessary amount of research in design Bureau and TSAGI, while increasing its angle of sweep and reducing to 4.2 — 5% relative thickness. This progressive constructive solution in the domestic aircraft industry, as it turned out, for a long time delayed the time of finishing machines.
Prototype double fighter-interceptor Yak-27 was built in December 1955, It was equipped with engines RD-9AK thrust 3250 kgf (with afterburner), and two guns of 30 mm caliber. Factory testing of the airplane (the leading test pilot of the G. A. Tinyakov and tester, K. B. Bekibaev) was held from 25 Dec 1955 to 25 April 1956, They showed that the flight characteristics of the Yak-27 mainly correspond to the instructions, with the exception of speed, does not exceed 1235 km/h (M = 1,15). The flight duration was three hours at an altitude of 12 000 m.
The parameters remained as in the Yak-25. In the forward part of the fuselage placed the modified radar sight “Falcon-M” (“Sokol-2”). The plane was equipped with standard navigation and communication equipment, in particular radio RSIU-4, automatic radio compass ark-5, radar interrogator-responder, SRZO-2 and marker receiver MRP-48П.
That summer, the Yak-27 was demonstrated at air parade in Tushino, after which NATO experts have given him the code name Flashlight-C, which means “beacon” or “torch” (choose what like).
In 1956 began the factory tests of the second instance of the interceptor, but with uprated engines RD-9F and designed for the suspension of two guided missiles. From its predecessor the airframes were reinforced wing and adjustable stabilizer. Compared to the first car to maximum speed without missile armament increased to 1400 km/h service ceiling brought up to 17,000 meters, the flight duration up to 2.5 hours.
During the tests, the interceptor has identified the Aileron reversal associated with insufficient rigidity refined wing. To increase means to increase the mass, which in turn would lead to lower performance. This task was solved by other means. With the wing removed the cantilever flaps and ailerons moved closer to the center. In addition, imposed additional speed restrictions. This work was performed in accordance with the order of the State Committee on aviation technology (GKAT) No. 622 dated 20 December 1956
It should be noted that in the same year, under the leadership of N. V. Grigorieva, studies were conducted on the deflection of the thrust vector of the engine to increase the ceiling of the plane. With this purpose made nozzle for nozzles with fixed angles of deflection of the jets, but in flight it’s a novelty, and not checked.
In 1957, at the Saratov aviation plant started the production of a pilot batch of Yak-27 with a modified wing, and the first machine flew pilot M. M. Chuvin.
January 31, 1958, during a routine flight accident the Yak-27 (serial No. 0103 with modified wing), released 30 December 1957 and fighter jet flown by a factory test pilot A. I. Grishin (Navigator Petlyakov). When landing, the aircraft was in a descending tray, the air hitting a pole tram wires and break the wires of the telephone line and landed before reaching the airport. After three and a half months the same pilot on the Yak-27 (serial No. 0203) due to false alarm of “fire left and right thrusters” landed with landing gear.
Emergency landing fighter-interceptor Yak-27.
The Yak-27V
In the mid-1950s, aircraft designers trying to raise the ceiling of the aircraft, were installed in the additional liquid-propellant rocket engines (LPRE), in 1940-ies. One of the initiators of the revival of this idea was E. Sawicki, in 1953 addressed this issue in the government. Not over this trend and the Yakovlev design Bureau. In accordance with the orders of the Ministry № 381 dated July 11, 1956 the first prototype of the Yak-27 in August of the same year, altered the Yak-27V, placed in the rear fuselage an additional power plant S-155 rocket engine with L. S. Dushkin. The crew expelled the radar operator, leaving one pilot. Removed some of the equipment and the drogue chute, thereby facilitating the car. Expanded the range of angles of installation of the stabilizer, now he has changed from + 4° to -2°.
It is known that at altitudes of about 18,000 m, the boiling point of human blood is approaching 36,6°, and in the case of cabin depressurization, this can lead to instant death of the pilot. For the safety of the pilot had in his equipment to enter the suit SI-3 (altitude-compensating suits did not exist), because the job provided you reach the speed of 2000 km/h and service ceiling of 25,000 m. LRE had to work at maximum thrust at an altitude of 20 000 m not less than three minutes.
According to the tactical and technical requirements of the customer, the Yak-27V was ordered to equip the radar “Diamond” gunsight ASP-5 NM, and guidance equipment “Horizon-1” and “Air-1”. Armament as the Yak-27: two guns NR-30 caliber 30 mm and 50 feathered NAR ARS-57M or 60 turbojet shells TRS-85, stabilized by rotation, or four TRS-190.
A sample prototype is built, using the first pre-production Yak-27. So far radar station “Almaz” by that time was in the development stage, nose fairing made of metal, kept the rear cabin of the operator, but without equipment. November 16, 1956 test pilot OKB G. A. Tinyakov performed on the Yak-27V (found the designation Yak-27РС), the first test flight without the inclusion of LRE. Lead engineer for the tests was V. A. of the Fence. However, to complete flight tests of the factory cars with the rocket engine failed because of the disaster on December 4, 1956 that day, according to the documents GKAT, test pilot G. A. Tinyakov was the flight with the aim to set a world altitude record. Before the pilot performed a 33-flight on the Yak-27, and three of them on the Yak-27V with the launch of the LRE.
Immediately after takeoff the plane with no seasoning went on the climb with progressive increasing a pitch angle. At a height of about 15 m, the pilot turned on the afterburner, but with 50 m, the Yak fell into a tailspin and hit the ground exploded. The most probable cause of the accident was considered a detachment from the concrete strip at a lower speed than normal. But, as said an employee of OKB. Yakovlev Y. M. Galinsky, the cause of the tragedy was the stabilizer mounted on the angle, different from the runway.
Looking ahead, I note that a year later under similar circumstances, another crashed Yak-27. Immediately after departing from the runway the aircraft nose up, lost speed and fell from a height of 80 — 100 m, killing test pilot LII A. N. Alferov and the commander of the regiment of Lieutenant Colonel V. S. Tsarev.
The second phase of testing began on 26 April and lasted to June 3, 1958 The second first flight of the Yak-27V, piloted by V. G. Mukhin, was held in may 1957 and the first flight with the inclusion of LRE — 15 may. As before, the lead engineer for the tests was V. A. of the Fence.
During flight tests were achieved a maximum speed of 1,900 km/h; Dynamic ceiling amounted to 23 500 m, with cash and 24 000 m. At the same time, specialists believed that this is not the limit and the ceiling can be raised to 26 000 m. the Flight to achieve maximum height were calculated as follows. Climb to 9000 m was made on the maximum output of the engines, then engaged the afterburner and the plane rose approximately 14 000 m. At this altitude, it accelerates to a speed of 940 — 960 km/h on the device and start LPRE with the subsequent transition in a climb. Since the rocket engine had two modes of operation, with minimal traction of the supply of fuel was enough for 264 seconds, while the maximum is 160.
In 1957, at the Saratov factory No. 292 began mass production has not yet passed the state tests of the interceptor. But next year, the government said all work on the cannon version of the Yak-27 was stopped, which caused Yakovlev protest. Alexander believed that cannon fighter to replace Yak-25. In early 1959, at the suggestion of the Chairman GKAT P. V. Dementyev also stopped work on the Yak-27V aircraft and SM-50 and E-50 OKB A. I. Mikoyan with a combined power plant.
Missile, the Yak-27K
The appearance of the interceptor, the Yak-27 coincided with the establishment of the first domestic homing missiles. On the basis of the government resolution of 30 March and GKAT order dated April 4, 1955 under rocket K-8 created team, which was led by M. R. Bisnovatyi, designed interceptor aircraft, designated the Yak-27K, and for developing and testing complex of the Yak-27K-8 converted four (three serial) Yak-27. The rocket launcher was located on devices placed between the fuselage and engine nacelles of the fighter.
The prototype Yak-27K was built in August 1956 the First stage of factory tests took place in September-November 1956-6 October of the same year, leading test pilot of the Yak-27K appointed G. A. tinyakova. Supervised factory tests of the missile C. G. Gazzaev.
Factory testing of the missiles K-8 (no starts) started in Zhukovsky on two flying laboratory Yak-25M. Then, after the death of tinyakova, they continued on the prototype of the Yak-27K-8 test pilot V. M. Volkov. These flights showed that the service requires fine-tuning, drawn up in the spring of 1957, the Next phase of flight tests of missile began in may 1957. In the summer they were joined by the second serial Yak-27 (serial No. 0201).
Flight tests of the “eight” started in Vladimirovka (now the town of Akhtubinsk, Astrakhan region), where the 6th research Institute of the air force in January 1958, the First flight of the Yak-27K in Vladimirovka 17 January 1958 ended in disaster. After separation from the runway and the front wheel of the plane there is a tendency to further increase in angle of attack. Piloting the Yak-27K commander of aviation combat use of A. M. Khitrov and test pilot LII B. N. Zawadzki could not cope with the machine, because the stabilizer was standing at an angle of minus 0.25° instead of plus 1.5°. The result is a progressive increase in angle of attack resulting in loss of speed and stalling.
After this incident, testing of the Yak-27K instructed the pilots of the NII VVS. In particular, it flew G. T. Beregovoy, A. S. Petrosyan and P. F. Cabrales, as well as the radar operators and boatmen inkov. From industry tests K-8 engaged in the pilots M. P Kiriaev, M. L. Petushkov and V. A. Shevchenko.
From 12 April 1958 started production tests of three production aircraft, a modified variant of the interceptor, the Yak-27K (factory No. 0503, 0104 and 0204) with radar “Socop-2K” and the RD-9F. Radar station, later renamed “eagle”, developed in OKB-339 map under the direction of G. M. she complained.
The results of tests of the Yak-27K reached a top speed of 1270 km/h, which exceeded the calculated ceiling — 16 300 m (apparently without the missiles), flight duration missile — 1 hour 27 minutes. The maximum range was 1260 km.
From the memoirs by S. A. Mikoyan, it follows that the first radio-controlled target Il-28M it and the operator Burlakov was shot down by a missile K-8, equipped with thermal homing head, 20 February 1958, However, from the documents GKAT, it follows that during the factory test Yak-27K first target Il-28M was shot down on 23 and 29 may 1958
In accordance with the order of the government in 1958 have resulted in the Saratov ordered make up from last year’s backlog 19 interceptor intended for the testing of guided missiles, machinery and engines, improvement of system of interception and the accumulation of experience of operating rocket engine.
For the BBC planned to transmit four Yak-27 gun armament and two Yak-27K missiles K-8. For the aviation industry — eight cars Yak-27K missiles K-8 and five Yak-27V with LRE. All in all, the plant № 292 built in 1957, 10 interceptors Yak-27 of different modifications, including three Yak-27K in the next year or five Yak-27V. Eight of LIH were with a modified wing, differing offset to the root rib of the Aileron and peeled down his socks end portions.
Yak-27K remained among the experimental machines, but has contributed to testing and debugging missiles K-8. As the interceptor. Yak-27K had a lack of speed and short duration of the flight. In that time we have developed a more rapid and complementing each other interceptors, the su-11 and Tu-128.
Reconnaissance Yak-27R
As already mentioned, the development of the fighter-scout with engine AM-9F (RD-9F) began in accordance with the March 1956 decision of the government of the USSR. The aircraft was designed for tactical and operational-tactical intelligence in daytime conditions.
In accordance with the performance requirements of aircraft engines M-9F, operating in the afterburner mode, was to develop a speed of 1400 km/h at an altitude of 11 000 m (and at maximum capacity — 1250 km/h) and climb to a height of 16 000 to 17 000 m. Maximum range was set not less than 3500 km a practical cruising speed of 600 — 700 km/h at altitudes of 12 000 to 14 000 m and 7-percent air navigation fuel capacity — 3000 km flight duration reached 3 hours. The Yak-27R had to climb to a height of 10 000 m in 3 minutes a run and the run does not exceed 1000 m. unlike the fighter / interceptor it was provided to install a 23-mm cannon with an ammunition load of 50 rounds. However, as you will see later, to implement all requirements failed.
For tests at the pilot plant № 115, Moscow has built two cars, and the first of them (side number 01) was converted from Yak-27. The initial stage of factory tests lasted from 28 April to 30 August 1956, Leading the aircraft were pilot G. A. Tinyakov and engineer K. B. Bekibaev.
High-speed aircraft photo reconnaissance Yak-27R:
1 — Pitot-PVD-7; 2—cabin Windows of the Navigator; 3 and 23 of the antenna I range fixed wing Radiotechnika SRO-2; 4—window cab of the Navigator; 5—cover the entrance hatch of the cockpit of the Navigator, 6 maintenance hatch compartment on-Board equipment; 7—canopy of canopy pilot; 8—movable part of the canopy pilot; 9 hatch fuel filler neck sealing system of the lamp; 10—filler fuel tanks; 11—non-directional antenna automatic direction finder ark-5; 12—the gauge of temperature of external air; 13—gargrot; 14—dorsal fin; 15 Kil; 16—operational access holes for wiring access control rudders; 17—maintenance hatch for maintenance of machine tool components and assemblies, 18—hatch cover operating mechanism permutation stabilizer; 19—radiotransparent Radome of the antenna of the radio station R-835; 20—rudder; 21—trimmer of the rudder; 22—tail navigation light; 24— blister sight, vizier MF-2P; 25—antenna range II aircraft of Radiotechnika SRO-2; 26—strut; 27—cylinder cleaning (release) a-pillar; 28—brace; 29—wheel (600х155 mm); 30—the plug; 31—shield 32—nacelle of the engine RD-9F; 33—hole for outlet of the cooling air; 34-1050-l external fuel tank (the maximum permitted filling < = 900 l); 35—fuel filler pipe; 36—anti-flatter load; 37—Aileron; 38—intakes air cooling adjustable nozzle turbojet; 39—adjustable stabilizer; 40— handlebar height; 41 and 42—hatches cameras for routine shooting, AFA-42/100 or AFA-42/75; 43—Luke’s camera for the topographical survey of AFA-41/10; 44—fold niches main landing gear; 45—flap-flap; 46—landing-taxiway spotlight; 47—fairing cannons NR-23; 48—fold niche nose landing gear, the 49—bar radio loop antenna, ARC-5; 50—preselection corner of the map; 51—two-point speed indicator; 52 is a pointer altimeter; 53—the pointer of the radio compass ark-5; 54—thermometer; 55—suspension arm; 56—absorber; 57—the wheel (800×230 mm); 58 panel; 59—strut; 60 male; 61—the wheel (310×135 mm), 62—plate; 63—antenna system for the protection of the tail “Siren-2”; 64—fairing compass sensor ID; 65—fold drag parachute container; 66—ventral ridge of the radio waves with an antenna of the system of “blind landing” MCI-56; 67—receiving antenna of the radio altimeter RV-2; 68—transmitting antenna of the altimeter RV-2; 69—whip antenna VHF radio RSIU-5V; 70 antennas of III range aircraft of Radiotechnika SRO-2; 71—cassette flares; 72—aerodynamic bulkhead; 73—controls motors; 74—crane chassis with switch; 75—DC voltmeter; 76—indicator panel of the chassis, a 77—position of the stabilizer; 78—pointer altimeter PRV-46; 79 lamp tricolor alarm, 80—altimeter two-point VD-20; 81—turn indicator EUP-53; 82—artificial horizon AGI-1; 83—reflex sight CRPS; 84—variometer VAR-150; 85—pointer of the tachometer ITE-2, 86—index of the gas thermometer from the kit 2TVG-411Т, 87—pointer kerosinoreza ESCS-1777; 88—pointer of the boost gauge tanks, MI-8; 89—pointer of the compass and radiolucency UGR-1; 90—handle control of the aircraft, 91 clock, ECHO; 92—combined speed indicator KUS-2000; 93—two-point pointer pressure gauge hydraulic УИ2-150; 94—the index number M; 95 crane flaps-flaps.
According to the results of flight tests of the second instance of the prototype was modified milongero part of the wing, replacing in this area of the dural lining of steel. Also found a hard ending, which increased the wingspan to 0.7 m, and a heavier anti-flatter loads.
State tests of the Yak-27R was held from 8 August 1958 to 11 February 1959 on the prototype aircraft with tail number 02. Leading at this stage was the engineer O. N. Yamschikova, pilots P. N. Blasnik and P. F. Cabrales, navigators V. I. Volkov and I. P Failures. The pilots of the overflight — Adrianov B. M. and S. A. Mikoyan.
The equipment of the aircraft includes: radio VHF RSIU-4V, KV — 11РСБ-70 receiver US-9ДМ, radio compass ark-5, security system tail “Sirena-2”, the defendant SRO-2, a radio marker MRP-56Л, altimeter RV-artillery radio R-108. Weaponry included a cannon NR-23 ammunition 50 rounds and reflex sight CRPS. In a blister the Navigator was the trailer-viewfinder-DF-2P, intended for correction of artillery fire. Aerial cameras AFA-42/100, AFA-42/70 and AFA-42/50 fastened ka suspension install AKUFO-33M.
The Yak-27R from the TV intelligence apparatus “Burevesnik”.
According to the results of state tests, experts recommended to launch the Yak-27R in series production, but with the removal of the defects.
In the spring of 1959 the air force Institute for control tests showed serial Yak-27R (serial No. 0102) manufactured by Saratov plant № 292. Compared with the prototype of the Yak-27R with tail number 02 for serial car in the rear fuselage mounted brake parachute PT-5240-57 with the dome area of 15.5 m2, removed the back seat of the Navigator and perekomponovkoy some equipment. Then mounted the device mechanical lock of the nose landing gear lever in the cockpit, a whip antenna of the command radio RSIU-4B placed on the keel, instead of a radio altimeter low altitude RV-set RV-2 changed the location of the antennas of the responder identification SRO-2. On the right side of the fuselage appeared a stub antenna connected radio 1РСБ-70M.
On serial Yak-27R blister viewfinder PV-2 was moved closer to the Cup seat of the Navigator 32 mm, installed more convenient ejection seat for the Navigator with the modified harness system, hydraulic motor GM-08 in the structure of the permutation stabilizer was replaced by the GM-36.
To increase the range in 1962, the aircraft with serial No. 0710 equipped with hardpoints under the wing of two resettable in flight fuel tanks. The car has passed the tests, and external fuel began to set on the scouts, from 14 series.
The production Yak-27R was carried out in Saratov from 1958 to 1962 and During this time has built 165 aircraft.
Basic data of aircraft-Yak-27
The Yak-27R started in the 47th separate guards reconnaissance regiment (ograp) at the airport Shatalovo in Smolensk region. The main event in the 47th ograp in 1960 were military tests of the Yak-27R, held from April 10 to October 1.
According to the results of military tests, the customer made a comment, inviting industry to equip the Yak-27R radar gun RBP-3 and night equipment illumination purposes. The design Bureau of A. S. Yakovlev tried to solve the problem, but to equip the aircraft with such systems is not reached through no fault of OKB reasons.
After the 47th ograp Yak-27R mastered several regiments. The last aircraft was seen in flight in the mid-1970s To the present day survived only five Yak-27R. One of them are in Monino air force Museum and Khodynka in Moscow and three in Germany.
The reconnaissance plane Yak-27R.
The first domestic supersonic reconnaissance aircraft, the Yak-27R was after the Il-28R next step for transition to the air force on more sophisticated machines Yak-28R and MiG-25RB. Although the aircraft did not fully comply with the requirements of the military early 1960s, but he did the most important thing — it is a good school and we have the necessary experience of hundreds of specialists of the air force, which subsequently make it easier to learn new scouts Yak-28R.
N. YAKUBOVICH
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