Category Mig

Ye-150

The Ye-150 experimental prototype was designed as a test bed for the new Mikulin/Tumanskiy R-15-300 turbojet. The intent of the aircraft – plus-engine project was to lay the foundation for a new generation of interceptors. The aircraft was designed to fly at speeds of about 2,800 km/h (1,510 kt) and altitudes of 20,000 to 25,000 m (65,600 to 82,000 feet).

The initial plan called for the new engine to be tested on a remote­ly controlled aircraft. This turbojet had a veiy short lifetime, but in that brief period it was powered up on the test bench, examined in flight, and even used to power a missile. It had a dry thrust of 6,705 daN (6,840 kg st) and a reheated thrust of 9,945 daN (10,150 kg st); its after­burner also had a second-stage nozzle called an ejector that supplied 19,405 daN (19,800 kg st) of thrust at Mach 2.4-2.5 and helped to clean up the base drag. For components particularly sensitive to the thermal

stresses (aerodynamic heating) that were the result of high speeds, the manufacturers decided to use heat-resistant materials such as stainless steel in place of duralumin.

The fuselage was shaped like a cylinder 1,600 mm in diameter except at the rear, where the diameter increased to 1,650 mm in the afterburner/ejector area. The shock cone in the engine air intake had a triple-angle profile and was made of dielectric material to house the antenna for the Uragan-5 interception system. The flow rate in the air inlet duct was controlled by a two-position translating ring. As soon as the aircraft reached Mach 1.65 the ring moved forward automatically; once the aircraft dropped back under that speed, the ring returned to its primary position.

The delta wing had a sweepback of 60 degrees at the leading edge, a thickness-chord ratio of 3.5 percent, Fowler-type flaps, and two-part ailerons with balance surfaces at the trailing edge. The wing could be fitted with two pylons for air-to-air missiles. The gear kinematics were standard: the nose gear strut retracted forward into the fuselage, and the main gear wheels also retracted into the fuselage while their struts folded into the wing. The cockpit was equipped with a curtain-type ejection seat. The fuel system included five fuselage tanks with a total capacity of 3,2701 (863 US gallons) plus two wet wing tanks that carried 245 1 (65 US gallons) apiece. The stabilator controls were boosted by two BU-65 power units, and those of the ailerons and rudder by two BU-75 power units. There were two separate hydraulic systems, one primary circuit and one for the servo-controls. The main circuit served the gear, the flaps, the three airbrakes on the underside of the fuselage, the translating ring on the air intake, and the surge bleed valve (on the fuselage sides) while also acting as a backup for the servo-control units. The PT 5605-58 tail chute measured 18 m2 (193.7 square feet). The cockpit hood was made of T2-55 glass, a 12-mm-thick material capable of withstanding 170° C (338° F) in aerodynamic heating.

The Ye-150 rolled out in December 1958 and was first piloted by A. V. Fedotov on 8 July 1960. During the fourth flight, on 26 July, aileron flutter was observed at Mach 0.925. The problem was quickly solved by fitting a damper on the aileron controls. After the fifth flight the tests had to be suspended because the casing of the engine gearbox had cracked. Tests resumed on 18 January 1961 with a brand-new R-15-300 turbojet. From 21 January to 30 March the aircraft made eight more flights and reached Mach 2.1 at 21,000 m (68,900 feet). After a second engine change, the Ye-150 made another twenty flights and hit a top speed of Mach 2.65 at 22,500 m (73,800 feet). At that point the ejector was replaced and the cockpit’s thermal insulation improved; tests resumed on 14 November 1961 and ended on 25 January 1962. There were forty-two flights altogether. Tests of the Uragan-5 complex with two K-9 missiles were not carried out until the Ye-152 A was ready a lit­tle later.

Specifications

Span, 8.488 m (27 ft 10.2 in); overall length (except probe), 18.14 m (59 ft 6.2 in); fuselage length (except cone), 15.6 m (51 ft 2.2 in); wheel track, 3.322 m (10 ft 10.8 in); wheel base, 5.996 m (19 ft 8 in); wing area, 34.615 m2 (372.6 sq ft); empty weight, 8,276 kg (18,240 lb); take­off weight, 12,435 kg (27,405 lb); fuel, 3,410 kg (7,515 lb); wing loading, 359.2 kg/m2 (73.6 lb/sq ft); max operating limit load factor, 5.1.

Performance

Max speed, 1,210 km/h (653 kt) at sea level; 2,890 km/h at 19,000 m (1,560 kt at 62,300 ft); climb to 5,000 m (16,400 ft) in 1 min 20 sec; to

20,0 m (65,600 ft) in 5 min 5 sec; service ceiling, 23,250 m (76,260 ft); landing speed, 275-295 km/h (148-160 kt); endurance, 1 h 50 min; range, 1,500 km (930 mi); takeoff roll, 935 m (3,065 ft); landing roll, 1,250 m (4,100 ft).

The Ye-7/1 and Ye-7/2 were both direct descendants of the Ye-6T. The MiG-21P was therefore a direct descendant of the MiG-21F, with the same R-11F-300 turbojet but a new 170-1 (45-US gallon) fuel tank behind the cockpit. To make the aircraft usable at rough strips the main gear was fitted with bigger wheels (type KT-50/2, tire size 800 x 200), and to shorten its takeoff roll two attachment points were added under rear fuselage for two solid propellant ‘‘accelerators" that could be dropped after ten seconds of burning time. The Ye-7s had the KAP-1 autopilot, but oscillations were damped on the roll axis only.

The MiG-2 IP was the first member of the family without cannons. The new air-battle concept prevailing at that time called for missiles to be the only armament of fighter aircraft It was thought that the consid­erable increase in fighter speed had ended the era of close combat. Confined conflicts such as the Vietnam War would reveal the errors of that doctrine.

The MiG-21P was also the first member of the family to be equipped with a real interception system, the MiG-21 P-13, which included TsD-30T radar (with surveillance, acquisition, tracking, and fire control modes), command receiver, SOD-57M decimetric transpon­der, Vozdukh-l-Lazur guidance system, KSI navigation system, IFF interrogator, and two K-13 IR homing air-to-air missiles. In place of missiles, the MiG-21P could cany unguided rocket pods, bombs, and even napalm containers. For ground-attack missions the pilot had the PKI-1 gunsight, which could also be used in the event of radar failure. The ejection seat was of the SK type.

The Ye-7/1 prototype made its first flight on 10 August 1958, the Ye-7/2 on 18 January 1960. The factory tests, conducted by P. M. Ostapyenko and I. N. Kravtsov, ended on 8 May 1960, and production was launched in June The performance of the MiG-21 P was identical to that of the MiG-21F except for the service ceiling, which increased to 19,100 m (62,650 feet); the climb rate at sea level in clean configura­tion, which was reduced to 150 m/sec (29,530 ft/min); and the landing roll with tail chute, which was reduced to 650 m (2,130 feet). Its maxi­mum operating limit load factor was 7 8

In the mid-1960s the MiG OKB, in cooperation with the Kazan Aviation Institute (KAI), developed versions of the MiG-21 PF and MiG-21 PFM to be operated as remotely controlled target drones for WS and PVO pilots as well as AAA gunners. For this purpose, fighters that had out­lived their operational parameters were used.

The radar in these aircraft was replaced by ballast to restore the aircraft’s trimming. The ejection seats were removed to make room for remote control equipment and the drive mechanism for the control surfaces. The target drone was controlled by radio signals from the ground or from another aircraft specially equipped to steer the drone with preset routines. Those modifications were carried out in the WS ARZs (air force overhaul workshops). The remotely controlled MiG – 21Ye could take off and make maneuvers, but only within the subsonic flight envelope.

IVHG21K

This experimental version of the MiG-21 bis was designed to develop new on-board systems to be installed in cruise missiles and was, like the MiG-21 bis, powered by an R-25 turbojet.

The MiG-25R was a high-altitude supersonic reconnaissance aircraft cast in the same mold as the MiG-25P interceptor. It was designed and built in 1961 and 1962. Externally, the Ye-155R-1 was different from the Ye-155P-l except for the forward fuselage (right up to bulkhead no. 1), which housed the reconnaissance systems, and the wing tip fuel tanks (capacity 1,200 1 [317 US gallons]), which could not be removed because they held the winglets. The fin tips had a more square shape. The internal modifications were limited to the refurbishing of the cockpit and electronics compartment as well as the installation of addi­tional antennae. To increase the operating range, the adjustable-area nozzles were fitted with larger flaps; the fuel capacity was increased by adding built-in tanks (350 1 [92 US gallons] each) to both fins and by •These records were still standing as this book went to press.

The Ye-155R-1 the first prototype of the MiG-25R. The wing – with no anhedral—had fuel tanks at the tips supporting a downward-canted winglet (the Soviets called it a flip­per).

On the third prototype, the Ye-155R-3 numbered 3155, the wing tip fuel tanks were replaced by antiflutter bodies. The wing has a 5-degree anhedral.

developing a huge auxiliary fuel tank (5,3001 [1,400 US gallons]) for the underbelly.

The MiG-25R-l was first flown on 6 March 1964 by A V. Fedotov, OKB chief pilot. It was powered by two R-15B-300S rated at 7,350 daN (7,500 kg st) dry and 10,005 daN (10,210 kg st) with afterburner. The first test flights led to a number of modifications that were introduced on the МІО-25Р These changes were made gradually. On the third pro­totype or Ye-155R-3 (the number 3155 tagged on its nose, it was one of the first four MiG-25s used for the Domodyedovo air display in July 1967) the wing tip fuel tanks and the winglets were replaced by anti­flutter bodies, the wing chord was increased significantly, the leading edge compound sweepback was rubbed out (and replaced by a constant 41 degrees), the fin tips were given a bevel shape, and the canard sur­faces were retained. Not until later was the fin area enlarged, the slab tailplane granted a taileron function, the ventral fin area reduced and the aircraft powered by its definitive engines, two R-15BD-300s rated at 10,975 daN (11,200 kg st) with afterburner

After passing the factory tests, the state acceptance trials, and the military acceptance inspections, the Ye-155 entered production in 1969 in the Gorki factory It was also decided that year to give the aircraft a bombing capability, in 1970 the new version, the MiG-25RB passed its tests and entered the production phase Simultaneously, all MiG-25Rs already built were upgraded with retrofit kits to the standard of the MiG-25RB reconnaissance-bomber variant, which was the progenitor of many specialized subtypes such as the MiG-25RBK (к standing for Kub—“cube"—the nickname of its SLAR radar) MiG-25RBS (1972), MiG-25RBV (v standing for Virazh—"turn”—the nickname of its SLAR radar), and MiG-25RBT (1978) These later models differed only in their electronic intelligence or navigation systems

When the basic MiG-25R (RB) was developed, the OKB had to face a number of difficult technical problems

—the aircraft had to be capable of cruising for great distances at Mach 2.35 and flying at Mach 2.83 with its full external bomb load —it had to be able to escape the interceptors and missiles of hostile air forces for the decade to come (1970-1980) by relying on its speed, ceiling, maneuverability, and electronic countermeasures (ECM) equipment

—a highly accurate, automatic homing bombing system had to be invented to attack ground targets at known coordinates from supersonic speeds and altitudes above 20,000 m (65,600 feet), around the clock and in any weather conditions —a highly accurate inertial navigation unit had to be developed (the USSR’s first) to tie together the DISS system (doplerovskiy izmeritel skorosti г snosa a Doppler radar to compute ground speed and

This remarkable aerial photograph was taken near Cairo in 1971 by a MiG-25 flying at 22 000 m (72,160 feet) and 2,500 km/h (1 350 kt). The camera, with a 650-mm focal length could cover a strip of ground equal to five times the aircraft’s altitude—in this instance, 110 km (68 miles) Foreground, the pyramids.

drift) and other course correction devices; a bank of digital com­puters (another first) linked to the automatic flight control system initiated on a preset path the release of bombs or the activation of reconnaissance equipment

—three interchangeable bays had to be engineered to house various types of powerful high-resolution cameras capable of covering a strip 90 km (56 miles) wide

—electronic intelligence equipment had to be incorporated, such as the SRS-4A(4B) on the MiG-25R (RB) and the SRS-9 on the MiG-25RBV

—a network of ground stations had to be established to pick up the data transmitted by the aircraft

—the performance of the Peleng ("bearing") navigation system had to be improved

The MiG-25R had no armament (neither cannons nor missiles) and could rely only on its speed and ceiling attributes to escape any attacker.

For photo-reconnaissance missions, the MiG-25R might have two left-right rotating cameras in one of its three interchangeable hays. One camera could have a focal length of 650 mm and be capable of covering a strip of ground equal to five times the flight altitude, while the other might have a focal length of 1,300 mm to cover an area half that long. The two cameras shot obliquely through two port and two starboard ports. A vertical camera with a short focal length was located under the cockpit to make the linking shots.

The MiG-25RB could carry six 500-kg (1,100-pound) bombs, four under the wing and two under the fuselage. Structurally significant items were strengthened at the bomb-launcher attachment points. The MiG-25RB, RBK, and RBS were commissioned for the WS in 1972 by the council of ministers. Those three versions as well as the MiG- 25RBV were produced until 1972. The MiG-25 reconnaissance variant was exported to Bulgaria, Algeria, Syria, India, Iraq, and Egypt[11] Dur­ing the Iran-lraq war, the Iraqi MiG-25Rs were upgraded to the RB stan­dard by field service personnel.

The exceptional advantages of the MiG-25RB and RBV were greatly appreciated by their operators extent of the ground area swept during a single flight by either the cameras or the elint equipment, high-speed long-distance flight, and near invulnerability to air defenses of the time. It is not widely known that MiG-21 Rs were used by branches of the public authorities for tasks such as demarcating regions affected by forest fires, snow, or floods. They were so quick and economical that neither satellites nor aircraft built especially for aerophotogrammetry (such as the An-32) could ever compete.

Specifications

Span, 13 418 m (44 ft 0 3 in); length (except probe), 21.55 m (70 ft 8 4 in); height, 6 5 m (21 ft 3 9 in); wheel track, 3 85 m (12 ft 7 6 in); wheel base, 5 138 m (16 ft 10.3 in); wing area, 61 4 m2 (660 9 sq ft), takeoff weight, 37,000 kg (81,550 lb); max takeoff weight, 41,200 kg (90,805 lb); fuel, 15,245 kg (33,600 lb); wing loading, 602 6-671 kg/m2 (123 5-137 6 lb/sq ft)

Performance

Max speed, 3,000 km/h at 13 000 m (1,620 kt at 42,640 ft); max speed at sea level, 1,200 km/h (648 kt); max Mach, 2.83, climb to 19,000 m (62,320 ft) in clean configuration in 6.6 min; with a 2,000-kg (4,400-lb) bomb load in 8.2 min; service ceiling in clean configuration, 21,000 m (68,880 ft); range at supersonic speed, 1,635 km (1,015 mi); range at subsonic speed, 1,865 km (1,160 mi); range at supersonic speed with 5,300-1 (1,400-US gal) auxiliary fuel tank, 2,130 km (1,320 mi); range at subsonic speed with 5,300-1 (1,400-US gal) auxiliary fuel tank, 2,400 km (1,490 mi).

It took until the end of the MiG OKB’s fifth decade and the start of the konversiya for the first real civil project to find its way to the design bureau’s drawing boards. This project was not initiated either by

Aeroflot or by a foreign airline. It was instead a purely homemade product searching out its own customers—or even partners. And it is not the only such project in the OKB’s files.

During the summer of 1946, the Soviet command authorities decided that the first ten MiG-9 s would take part in the flyover at Red Square on 7 November The builders had no time to lose. The NKAP decree of 28 August 1946 stated: "Our aim being to produce the MiG-9 as soon as possible and to give the pilots time to train and get a feel for the machine, chief constructor A. I. Mikoyan and factory manager V. Ya. Litvinov are assigned the task of producing a small series of this air­craft (ten units).” By 22 October the ten aircraft were completed. They were practically handmade, without any production tooling. On the morning of 7 November, the flyover was canceled because of adverse weather conditions. These first ten machines can be regarded as pre – production aircraft and were in no way different from the prototypes.

The production aircraft 1-301 (factory code FS, military designation MiG-9) was different in that RD-20 engines replaced the BMW 003s. The RD-20 was a 100-percent Soviet-made version of the BMW 003. It offered the same thrust, 784 daN (800 kg st), and its mass production was organized by D. V. Kolosov in the Kazan engine factoiy The land­ing gear of the MiG-9 was fitted with more efficient brakes, and its fuel system was equipped with a new type of fuel cell made with a rubber­ized fabric developed by the VIAM (Soviet institute for aviation materi­als). During the test flights of the first ten MiG-9s equipped with these cells, no leaks were noted. These cells allowed the engineers to put to use all of the space available in the aircraft structure. Their capacity was of the greatest importance because the engines were so thirsty.

The armament was similar to that of the prototypes: one N-37 with forty rounds and two NS-23s with 80 rpg The first production aircraft was rolled out on 13 October 1946 and first flown by M. L. Gallai on the twenty-sixth. The first MiG-9s were railroaded to the LII airfield, where they were taken up by GK Nil WS pilots M. L. Gallai, G M. Shiyanov, L. M Kushinov, Yu. A. Antipov, A. V. Proshakov, A. V. Kotshyetkov, and D. G. Pikulenko. All these men as well as a few young air force pilots had trained hard to celebrate the October Revolution.

It was not long before the first service evaluation flights revealed the aircraft’s design flaws and shortcomings related to defective work­manship. Some of these could be corrected without difficulty, but oth­ers were more serious. For instance, when all three guns were fired simultaneously above 7,500 m (24,500 feet), the two jet engines fre­quently flamed out. It was later discovered that this phenomenon was a distinctive feature of all jet engines, and many years of research were needed worldwide to resolve this problem. It was part of the price an aircraft designer paid for doing without a propeller.

Test flights also demonstrated that jet aircraft needed airbrakes, and that above a speed of 500 km/h (270 kt) the pilot could not bail out. This led to the development of the first ejection seats. Other needs were brought to light as well, such as cockpit pressurization and fire protection in the engine bay. And soon it became obvious that a two – seat training aircraft with the same flight envelope as the single-seater had to be a priority.

The first jet engines were heavier than piston engines; the advan­tages of not having a propeller could be appreciated only at high speeds. This explains why the takeoff roll of the MiG-9 was so long: 910 m (2,985 feet), as opposed to 234 m (768 feet) for the MiG-3. And yet the primary goal—to increase flight speed—was fully achieved thanks to the jet engine

Specifications

Span, 10 m (32 ft 9.7 in); length, 9.83 m (32 ft 3 in); height, 3.225 m (10 ft 6.7 in); wheel track, 1.95 m (6 ft 4.8 in); wheel base, 3.072 m (10 ft 0.9 in); wing area, 18.2 m2 (195.9 sq ft); empty weight, 3,420 kg (7,538 lb); takeoff weight, 4,963 kg (10,938 lb); fuel, 1,300 kg (2,865 lb); oil, 35 kg (77 lb); gas, 7 kg (15.5 lb); wing loading, 272.7 kg/m2 (55.9 lb/sq ft).

Performance

Max speed, 911 km/h at 4,500 m (492 kt at 14,760 ft); max speed at sea level, 864 km/h (467 kt); climb to 5,000 m (16,400 ft) in 4 3 min, ser­vice ceiling, 13,500 m (44,280 ft); landing speed, 170 km/h (92 kt); range, 800 km (497 mi); takeoff roll, 910 m (2,985 ft); landing roll, 735 m (2,410 ft).

The VVS needed a two-seater to familiarize pilots with the operation of the RP-1 Izumrud radar. For this purpose the nose of the UTI MiG-15 was modified to resemble that of the MiG-15P bis (SP-5). The instru­ment panel of the student’s cockpit in front was identical to that of the single-seat fighter.

The armament on this trainer was limited to one 12.7-mm UBK-E machine gun. The ST-7 passed its acceptance tests in 1952, but its pro­duction run was limited. Its flight performance did not differ signifi­cantly from that of the UTI-15.

The purpose of this program was to convert the MiG-17 day fighter into an all-weather night fighter. The radar developed for the new air­craft was supposed to provide target scanning and fire control capabili­ties day and night as well as in clouds.

The SP-7, powered by a VK-1A rated at 2,645 daN (2,700 kg st), dif­fered from the MiG-17 in the nose section, which was modified to accommodate the RP-1 Izumrud radar designed by V. V. Tikhomirov. This modification led engineers to redesign the cockpit windshield and to rearrange the armament. The N-37D cannon of the MiG-17 was replaced by another NR-23, for a total of three NR-23 cannons with 100 rpg. Protection for the pilot included a bulletproof windshield, an armor plate in front of the cockpit, an armored headrest, and an armored seat back.

The SP-1 radar was combined with an ASP-3N gunsight and had two antennae: one (for scanning) housed in the upper lip of the engine air intake, and one (for ranging and fire control) housed in the air intake partition. Once the target was within 2 km (1.24 miles) the fire control antenna activated automatically to sharpen the pilot’s aim. In clear weather the radar was disconnected, and the pilot used the gun – sight. With the exception of the aileron controls, which were boosted by a BU-1U servo-control unit, all systems were identical to those of the MiG-17.

G. A. Sedov was the first pilot to fly the SP-7; it passed its tests in the summer of 1952. After certification as the MiG-17P, it was mass – produced for the PVO and land-based naval aviation. Approval was expedited by the fact that the RP-1 radar had been installed beforehand on the SP-5, a modified MiG-15 bis. Development of the RP-1 continued in 1953 on the ST-7, a version of the UTI MiG-15, in various weather conditions.

The MiG-17P was flown only by above-average pilots. It was the first radar-equipped lightweight interceptor ever built in the USSR.

Specifications

Span, 9.628 ш (31 ft 7 in); length, 11.680 m (38 ft 3.9 in); height, 3.685 m (12 ft 1 in); wheel track, 3.849 m (12 ft 7.5 in); wheel base, 3.44 m (11 ft 3.4 in); wing area, 22 6 m2 (243 3 sq ft), empty weight, 4,154 kg (9,155 lb); takeoff weight, 5,550 kg (12,232 lb); max takeoff weight with two 400-1 (106-US gal) drop tanks, 6,280 kg (13,841 lb); wing loading, 245.6-277 9 kg/m2 (50.3-57 lb/sq ft); max operating limit load factor, 8.

Performance

Max speed, 1,115 km/h at 3,000 m (602 kt at 9,840 ft); max speed at sea level, 1,060 km/h (572 kt); climb to 5,000 m (16,400 ft) in 2.5 min; to

10,0 m (32,800 ft) in 6.6 min; to 14,000 m (45,920 ft) in 16.2 min; climb rate at sea level, 37 m/sec (7,280 ft/min); landing speed, 180-200 km/h (97-108 kt); range, 1,290 km at 12,000 m (800 mi at 39,360 ft); with two 400-1 (106-US gal) drop tanks, 2,060 km (1,280 mi); flight endurance, 1 h 53 min at 12,000 m (39,360 ft); with two 400-1 (106-US gal) drop tanks, 2 h 58 min; takeoff roll, 630 m (2,065 ft); land­ing roll, 860 m (2,820 ft).

In 1955 the cold war had turned up the heat on more than one political leader Soviet airspace was being systematically violated by balloons carrying all sorts of detection equipment and by high-flying Canberra reconnaissance aircraft It was at this time that the ОКБ first received information about the development in the United States of the Lock­heed U-2, a reconnaissance aircraft that had a service ceiling of 25,000 m (82,000 feet). The situation was deemed serious because the USSR did not have a single aircraft capable of intercepting such high-altitude invaders.

A crash program was set up to counter the threat. The consensus was to build specialized high-altitude interceptors and in the meantime to modify the MiG-19S to improve its service ceiling—hence the "V" of the designation, which stands for Visotrdy (altitude). The ОКБ quickly decided to make the following changes in the production aircraft:

—increase the wing area by 2 m2 (21.5 square feet)

—remove the two NR-30 wing cannons; only the fuselage cannon was retained

—take the armor plate out of the pilot’s seat back —raise the turbine inlet temperature (TIT) of the AM-9B to 730° C (1,378° F); the modified engine was renamed the AM-9BF —add a 12-degree flap setting to be used at 15,000 m (49,200 feet); the deployment of flaps during flight maneuvers marked a first in the USSR

G. K. Mosolov and V A Nefyedov dealt briskly with the SM-9V tests under the management of V. A. Arkhipov. The prototype was then handed to military test pilots. During high-altitude flights, the KKO-1 oxygen dispenser was tested. It secured a high oxygen pressure in the pilot’s mask. Moreover, a research center designed and tested the VSS-04A pressure suit, a piece of equipment that was considered essential because the smallest pressure loss at high altitudes—whether caused by a direct hit or a tiny crack in the cockpit hood—could lead to the pilot’s death. The pressure suit was also vital in case the pilot need­ed to eject at high altitudes and high speeds. The OKB brain trust, with Mikoyan in the lead, agreed to give the highest priority to the develop­ment of this pressure suit within the context of the SM-9V program.

The VSS-04A tests were carried out by two OKB pilots, К. K. Kokki – naki and V. A. Nefyedov, first in an altitude chamber and then in flight. In the altitude chamber, both pilots "climbed” to 25,000 m (82,000 feet), a first in the USSR. The suit was developed very quickly, and its use became normal practice. Soon afterward, the pressure suit was supple­mented by the GSh pressure helmet. The combination allowed pilots to fly as high as 24,000 m (78,700 feet). OKB pilots G. A Sedov, К. K. Kokkinaki, and G. K. Mosolov and military test pilots S. A. Mikoyan, V. P. Vasin, and V. S. Ilyushin quickly got used to the high-altitude equip­ment and to the SM-9V, which was mass-produced as the MiG-19SV. On 6 December 1956 N. I. Korovushkin, a GK Nil VVS pilot, climbed to the record altitude of 20,740 m (68,030 feet) by using the zoom technique.

(A zoom is an optimized steep climb at high altitude, normally starting at the aircraft’s maximum level Mach and trading speed for height to reach exceptional altitudes far above its sustainable level ceiling.)

The test report on the USSR’s first high-altitude interceptor reads, "The MiG-19SV does not differ much from the MiG-19S as far as han­dling technique is concerned. On the other hand, at low speeds in the 350-380 km/h [189-205 kt] range the aircraft handles better and proved to be steadier in flight than the prototype." Several MiG-19SVs were powered by AM-9BF and BF-2 turbojets rated at 3,235 daN (3,300 kg st). One of them topped 1,572 km/h at 10,000 m (849 kt at 32,800 ft).

Specifications

Span, 10 3 m (33 ft 9.5 in); overall length without probe, 12.54 m (41 ft 1.7 in); with probe, 14.64 m (48 ft 0.4 in), wheel track, 4.156 m (13 ft 7.6 in); wheel base, 4.398 m (14 ft 5.2 in); wing area, 27 m2 (290.6 sq ft); empty weight, 5,580 kg (12,300 lb); takeoff weight, 7,250 kg (15,980 lb); wing loading, 268.5 kg/m2 (55 lb/sq ft).

Performance

Max speed, 1,420 km/h at 10,000 m (767 kt at 32,800 ft); service ceil­ing, 19,000 m (62,300 ft).

Following close on the heels of the Ye-150, the OKB started work on the full-scale mock-up of a new prototype—the Ye-151— armed with a rotating twin-barrel cannon that was set on the forward fuselage struc­ture and that revolved around the air intake case axis. With the can­non (a 23-mm TKB-495 whose axis of rotation was perpendicular to its annular support axis) at its widest angle, a noticeable torque occurred that disrupted the aircraft’s three-axis stability and made it impossible to shoot accurately. For the Ye-151/2 the cannon and its support were moved behind the cockpit and thus closer to the aircraft’s center of gravity.

The Ye-151’s forward fuselage was longer than that of the Ye-150, but the dimensions of the air inlet duct did not need to be modified because the ammunition boxes and belts were transferred to behind the cockpit. Wind tunnel experiments proved that the internal aerody­namics of the extended duct improved the engine’s operation. This arrangement was retained for future aircraft of this family, starting with the Ye-152A.