Category Mig

The Ye-50 was designed in 1954 Although it was a member of the Ye- 2/Ye-2A family, it differed from them in many points First its power plant included the Mikulin AM-9Ye turbojet rated at 3,725 daN (3,800 kg st) and the Dushkm S-155 liquid propellant rocket engine capable of 1,275 daN (1,300 kg st) The AM-9Ye turbojet differed from the produc­tion AM-9B in several details that broadened its combat operating range (altitude and speed) and took into account the contribution of the rocket engine Second, the fuselage had to be lengthened to make room for the three propellant tanks for the rocket engine (К-fuel A – acid, T-hydrogen peroxide) as well as the combustion chamber above the turbojet’s exhaust nozzle. The accessory drive and turbopumps of the rocket engine were located in the fairing of the fin base The noz­zle throats for the rocket engine and the turbojet lined up Underneath the fuselage two lines for the combat emergency jettison device—treat­ed on the inside against corrosive acids—ran across the skm opening into the same plane as the nozzle throat On the other hand the for­ward fuselage, the wing, the slab tail, and the gear were not modified because those components were the subject of detailed engineering work with the Ye-2 and were at that time mastered by the manufactur­ing units The Ye-50 was armed with two NR-30 cannons

Three prototypes were built from 1955 to 1957 The Ye-50-1 rolled out in December 1955 It was first piloted by V. G Mukhin of the LII MAP on 9 January 1956 (the same day as the Ye-5) and first lit up its rocket engine in the air on 8 June The Ye-50-1 factory tests halted on 14 July after eighteen flights when the aircraft landed short of the run­way and was destroyed.

Ye-50/1; second from left, the dotted line shows the Ye-50/2 modifications; sec­ond from right, side view of the Ye-50/3 (MiG О KB four-view drawing)

The Ye-50/3 differed from both the Ye-50/1 and the Ye-50/2 by a noticeable lengthen­ing of the fuselage forward section.

The Ye-50/3 also differed from the two other prototypes by the new shape of its rear fuselage, which resulted in a shortened rudder

The Ye-50-2 was rapidly completed, and V. P. Vasin (also of the LII MAP) was put in charge of the tests. The Ye-50-2 differed from the first prototype in the modified shape of the rear end and in the patch dubbed the “knife" placed along the trailing edge of the rudder to increase the vertical fin area. Several unofficial altitude and speed records were beaten with the rocket engine in use. On 17 June 1957 Vasin climbed to 25,000 m (82,000 feet) and a little later reached Mach 2.23 or 2,460 km/h (1,328 kt).

The Ye-50-3, built in 1957, had a larger kerosene tank and a smaller hydrogen peroxide tank than its predecessors. The former cell-type tank for kerosene was replaced by a sheet metal tank fitted with a transfer pump. Also, the fuselage nose was lengthened, and the air intake lips were sharpened. The air intake cone had a double angle, and the rear end of the fuselage was modified once more. During a high-altitude flight of this prototype with N. A Korovin of the Nil WS at the controls, part of the tail fin caught fire. The aircraft became uncontrollable and went into a spin. The pilot ejected; unfortunately, the mechanism to separate the pilot’s seat and the canopy did not work, and the pilot was killed.

After reviewing carefully the reasons for the many shortcomings of rocket engines and their systems, it was decided to discontinue the Ye – 50 project. But the development of a new generation of fighters equipped with auxiliary power plants proceeded after a complete reap­praisal of the basic data concerning this kind of power unit. The goals of this new effort were to increase the effectiveness of the rocket engine’s control system and to safeguard the pilot and maintenance personnel (both aboard the aircraft and in the storage facilities) against any toxic components of the rocket engine propellants.

Specifications

Span, 8.109 m (26 ft 7,2 in); length (except probe), 13.625 m (44 ft 8.4 in) for the Ye-50-1; 14.85 m (48 ft 8.7 in) for the Ye-50-3; fuselage length (except cone), 12.32 m (40 ft 5 in) for the Ye-50-1; 12.715 m (41 ft 8.6 in) for the Ye-50-3; wheel track, 2.679 m (8 ft 9.5 in); wheel base, 5.22 m (17 ft 1.5 in); wing area, 21 m2 (226 sq ft); takeoff weight, 8,500 kg (18,735 lb); wing loading, 404.8 kg/m2 (83 lb/sq ft).

Performance

Max speed, 2,460 km/h (1,328 kt); climb to 10,000 m (32,800 ft) in 6.7 min; to 20,000 m (65,600 ft) in 9.4 min; static ceiling, 23,000 m (75,440 ft); zoom ceiling, 25,600 m (83,970 ft); landing speed, 280 km/h (151 kt); range, 450 km (280 mi); takeoff roll, 900 m (2,950 ft); landing roll, 860 m (2,820 ft).

The MiG-21M was the export version of the MiG-21SM. Soviet aircraft manufacturers never put their most recent engines or equipment into such models; consequently, the MiG-21 M was powered by the R-11F2S – 300 with 6,050 daN (6,175 kg st); the RP-22 radar was replaced by the RP-21MA (a modified RP-21M) linked to the ASP-PFD gunsight; and older RS-2US missiles were substituted for the R-3Rs. The maximum weapon load was 1,300 kg (2,865 pounds).

The MiG-21 M was mass-produced only for export in the MMZ Znamya Truda factory in Moscow between 1968 and 1971. India was granted the manufacturing license in 1971, and the first license-built MiG-21 M—referred to as Type 96—was delivered to the Indian air force on 14 February 1973 The aircraft continued to be built there until 1981.

Specifications

Span, 7.154 m (23 ft 5 7 in); fuselage length (except cone), 12 285 m (40 ft 3.7 in); wheel track, 2.787 m (9 ft 1.7 in); wheel base, 4.71 m (15 ft 5.4 in); wing area, 23 m2 (247.6 sq ft); takeoff weight, 8,300 kg (18,295 lb); max takeoff weight, 9,100 kg (20,055 lb); maximum takeoff weight on rough strip or metal-plank strip, 8,800 kg (19,395 lb); fuel, 2,200 kg (4,850 lb); wing loading, 360.9-395.7-382.6 kg/m2 (74-81.1-78.4 lb/sq ft); max operating limit load factor, 8 5.

Performance

Max speed, 2,230 km/h at 13,000 m (1,204 kt at 42,640 ft); max speed at sea level, 1,300 km/h (702 kt); climb rate at sea level (half internal fuel, full thrust) with two R-3S missiles, 115 m/sec (22,640 ft/min); climb to 16,800 m (55,100 ft) in 9 min; service ceiling, 17,300 m (56,740 ft); landing speed, 250 km/h (135 kt); range, 1,050 km (650 mi); with 800-1 (211-US gal) drop tank, 1,420 km (880 mi); takeoff roll, 900 m (2,950 ft); landing roll with SPS and tail chute, 550 m (1,800 ft).

The MiG-21MF was a modified MiG-21M reengined with the R-13-300 turbojet rated at 3,990-6,360 daN (4,070-6,490 kg st) and reequipped with the RP-22 Sapfir-21 radar of the MiG-21SM. The capacity of its fuel tanks was limited to 2,650 1 (700 US gallons), but the aircraft could cany either one 490-1 (129-US gallon) or one 800-1 (211-US gallon) drop tank under the fuselage and two 490-1 (129-US gallon) drop tanks under the wing. Like its predecessors, the MiG-21MF could be fitted with two SPRD-99 solid rocket boosters capable of 2,450 daN (2,500 kg st) apiece.

Armament included a built-in GSh-23L cannon with 200 rounds under the fuselage and, under the wing, four air-to-air missiles (two R – 3S and two R-3R), or two UB-32 and two UB-16 rocket pods (a total of ninety-six 57-mm S-5 rockets), or four 250- or 500-kg (550- or 1,100- pound) bombs, or any combination of these weapons, the maximum weapon load being 1,300 kg (2,865 pounds). The MiG-21 MF could also be armed with R-60 and R-60M air-to-air missiles for close combat.

The PVD-7 air data probe consisted of a ram air pressure inlet, three rows of static pressure pickups, and two pairs of weathercocks (one to measure the angle of attack [AOA] and the other to measure the sideslip angle). The pressure inlets fed the air data computer, and the weathercocks fed the fire control computer. It is noteworthy that these weathercocks had disappeared from the air data probe with the "old” MiG-21F. This probe did not normally send its data to the cockpit instrument panel—this task was left to a short Pitot head on the front starboard side of the fuselage—but it could serve as the primary Pitot – static probe in case of emergency. The pilot was informed via the instrument panel by the AOA indicator on the front port side of the fuselage. Other equipment included the AP-155 autopilot, the Sirena – 3M radar warning receiver, the SRO-2/SRZO-2 IFF transponder-inter­rogator, the SOD-57M decimetnc АТС transponder, the RV-UM radio­altimeter for 0-600 m (0-1,970 feet), the Lazur command receiver, and the new TS-27AMSh cockpit periscope.

The MiG-21MF was mass-produced in the MMZ Znamya Truda fac­tory in Moscow between 1970 and 1974 and in the Gorki factory in 1975.

Specifications

Span, 7.154 m (23 ft 5.7 in); fuselage length (except cone), 12.285 m (40 ft 3.7 in); height, 4.125 m (13 ft 6.4 in); wheel track, 2.787 m (9 ft 1.7 in); wheel base, 4.71 m (15 ft 5.4 in); wing area, 23 m2 (247.6 sq ft); empty weight, 5,350 kg (11,790 lb); takeoff weight with four R-3S/R missiles and three 490-1 (129-US gal) drop tanks, 8,150 kg (19,725 lb); max takeoff weight with two R-3S/R missiles and three 490-1 (129-US gal) drop tanks, 9,400 kg (20 720 lb); fuel, 2,200 kg (4,850 lb); wing loading, 356.5-389 1-408.7 kg/m2 (73.1-79 8-83.8 lb/sq ft); max operat­ing limit load factor, 8.5.

Performance

Max speed, 2,230 km/h at 13,000 m (1,204 kt at 42,640 ft); max speed at sea level, 1,300 km/h (702 kt); climb to 17,700 m (58,055 ft) in 9 min; service ceiling, 18,200 m (59,700 ft); landing speed with SPS, 270 km/h (146 kt); landing speed without SPS, 310 km/h (167 kt); range, 1 050 km (650 mi); with 800-1 (211-US gal) drop tank, 1,420 km (880 mi); with three 490-1 (129-US gal) drop tanks, 1,800 km (970 mi); hi-lo – hi radius of action, 370 km (230 mi) with four 250-kg (550-lb) bombs; 740 km (460 mi) with two 250-kg (550-lb) bombs; and two 490-1 (129- US gal) drop tanks; takeoff roll, 800 m (2,625 ft), landing roll with SPS and tail chute, 550 m (1,800 ft).

In the process of developing and upgrading the MiG-23 family, the MiG-23ML (rolled out in 1976) marked an important milestone that involved a complete refurbishing of the MiG-23M: a new engine, new systems, new missiles, and new radar capabilities The R-29-300 turbo­jet was replaced by a first-series Khachaturov R-35 (R-35-300) rated at 8,380 daN (8,550 kg st) dry and 12,450-12,740 daN (12,700-13,000 kg st) with throttleable afterburner Total fuel weight with three 800-1 (211-US gallon) drop tanks reached 5,500 kg (12,120 pounds)

The MiG-23ML differed from the MiG-23M in many other aspects as well:

—the trailing edge flaps were divided into three sections —the automatic flight control system was upgraded and renamed SAU-23AM

—the aircraft’s weight was reduced by removing the fourth fuse­lage tank

—the new Polyot ("flight”) flight management system was installed, including landing and short-range navigation systems, heading and vertical reference unit, and altitude and speed sensor; the Polyot was linked to the SAU-23M and could operate simultaneously —the forward-sector scanning and fire control system, upgraded and renamed S-23ML, featured the Sapfir-23ML radar, the TP-23M infrared sensor, and the ASP-17ML sighting system —six store points (four under the fuselage and two under the wing glove) carried the usual weaponry, including R-23R/R-23T air-to – air missiles to supplement the MiG-23M cannons and rockets — two UPK-23-250 gun pods housing GSh-23L cannons could be mounted beneath the wing

—the shape of the tail fin was modified by shortening the dorsal fin

This photograph dearly shows the shape of the type 3 wing with leading edge flaps The GSh-23L twin-barrel cannon is visible between the air intakes (Photo RR)

A MiG-23ML takes off with full reheat The undercarriage is retracting, and the ventral fin is already fully unfolded (Photo RR)

Close up of the R-35 afterburner’s flame holder rings. Foreground, the flap-type nozzle. (Photo RR)

A MiG-23ML lands in Finland with open tail chute. The new fin shape is a distinctive feature of this model. (Photo RR)

The MiG-23ML entered production in 1976 and was built until 1981. All were later upgraded to the MLD standard as quickly as they were returned to the overhaul shops. Aircraft of this type visited Fin­land and France as part of an exchange prqiect in 1978—without their IR sensor, however.

Specifications

Span (72° sweep), 7.779 m (25 ft 6.3 in); span (16° sweep), 13.965 m (45 ft 9.8 in); fuselage length (except probe), 15.65 m (51 ft 3.7 in); wheel track, 2.658 m (8 ft 8.7 in); wheel base, 5.772 m (18 ft 11.3 in); wing area (72° sweep), 34.16 m2 (367.7 sq ft); wing area (16° sweep),

37.35 m2 (402 sq ft); takeoff weight, 14,700 kg (32,400 lb); max takeoff weight, 17,800 kg (39,230 lb); wing loading (72° sweep), 430.4-521 kg/m2 (88.2-106.8 lb/sq ft); wing loading (16° sweep), 393.6-476.6 kg/m2 (80.7-97.7 lb sq ft); max operating limit load factor, 8.5 at < Mach 0.85, 7.5 at > Mach 0.85.

Performance

Max speed in clean configuration (72° sweep), 2,500 km/h or Mach

2.35 (1,350 kt); max speed in clean configuration (16° sweep), 940 km/h or Mach 0.8 (508 kt); service ceiling, 18,500 m (60,680 ft); ferry range, 1,950 km (1,210 mi); with three 800-1 (211-US gal) drop tanks, 2,820 km (1,750 mi).

MiG 25MP / ЇВ-155МР / 83 MiG31 / 01

The MiG-31 was intended to counter a very specific threat: that of American B-52 bombers carrying long-range cruise missiles, each bomber representing several potential dangers all by itself (and conse-

The Ye-155MP numbered 831—product 83, no. 1—was neither a MiG-25 nor a MiG-31. It has the latter’s characteristic landing gear, but the airbrakes had to be moved and the wing strengthened

The MiG-31 takes shape in its definitive silhouette. The airbrakes were moved under the air intake ducts. The staggered twin wheels of the main gear were distinctive

quently several targets) The future MiG-31 was to be capable of destroying multiple invaders at high or low altitudes in the forward and rear sectors and providing true look-down/shoot-down capability whatever the weather conditions, even if the invaders try to maneuver and use active countermeasures

At the start the prototype was referred to as the Ye-155MP On the aircraft’s nose the number “831" was painted to indicate that it was the first example of the izdehye 83 MiG’s internal product number The air – frame of this prototype was closely related to that of the Ye-155M. This was a sturdy, time-tested structure but the proportions of its metallic components were altered somewhat to 50 percent steel 16 percent tita­nium, 33 percent duralumin, and a negligible 1 percent composite materials (including the radome) The new aircraft did not need to be faster than the MiG-25P/PD, but it did need to offer a longer range This explains why the new aircraft—which was ten metric tons heavier than the MiG-25P/PD—was powered by two Solovyev D-30F6s rated at 9,310 daN (9,500 kg st) dry and 15,190 daN (15,500 kg st) with after­burner, the turbofan flight-tested on the Ye-155M,

In what ways did the MiG-25MP izdeliye 83 differ from the MiG-25 izdehye 99?

1. It was a two-seater, a second crew member (the flight engineer) was needed to help manage its avionics

2. Both airbrakes were located under the air intake duct’s outboard corners (in front of the main gear doors) and were obliquely hinged

3. The main gear retracted forward, but the single wheels were replaced by staggered twin wheels arranged so that the rear wheel never followed the furrow of the front wheel; because of the aircraft’s weight it was important to distribute loads carefully, taking typical Russian weather conditions into account (winter snows and spring slushes)

4. Unlike the MiG-25, flaps and ailerons took up the whole trailing edge

The Ye-155MP was first piloted on 16 September 1975 by A. V Fedotov, but four long years of tests were needed before starting pro­duction in the Gorki factory in 1979. Those tests led to several signifi­cant modifications before the MiG-25MP reached the izdeliye 01 MiG-31 production stage:

1 The whole of the wing’s leading edge was fitted with slats in four sections

2 Small, sharply swept leading edge root extensions were added

3. The aircraft was equipped with a semiretractable refueling probe on the port side of the nose cone

4. The wing box was strengthened by a third main spar so that the MiG-31 could fly at high supersonic speeds near the ground

5 Both airbrakes were moved squarely under the air intake ducts and hinged in the vertical plane

All of the MiG-31 ‘s combat capabilities relied on its interception system, which consisted of the S-800 Zaslon ("flanker") phased array look-down/shoot-down radar in the nose, the infrared search-and-track device in a semiretractable pod under the nose, and the tactical situa­tion display. The radar had effective ranges of 200 km (125 miles) in the forward clutter-free sector and 120 km (75 miles) in look-down mode. In the rear sector those figures are reduced to 90 km (56 miles) and 70 km (43 miles), respectively. Ten targets could be tracked simultaneously, and up to four could be simultaneously engaged. The simultaneous lock-on and firing sectors covered plus-or-minus 70 degrees in azimuth and -60 to + 70 degrees in elevation.

As regards navigation, the position-finding accuracy was not influ­enced by the system’s time in service. For long distances the Marshrut ("itinerary”) system—similar to the West’s Omega—was accurate to between 2 and 5 km (1.25 and 3.10 miles); this margin narrowed to between 1.8 and 3.6 km (1.1 and 2.2 miles) for flight distances between 2,000 and 10,000 km (1,240 and 6,210 miles). For medium-range navi­gation the Tropik—similar to the West’s Loran — was accurate to between 250 and 1,300 m (820 and 4,265 feet); this margin narrowed to

between 130 and 1,300 m (425 and 4,265 feet) for flights under 2,000 km (1,240 miles)

The combat capability of the MiG-31 also relied upon information transmitted by a ground network of automatic guidance stations (ASU) operating in the following modes: remote guidance, semiautonomous guidance (coordinated support), isolated operation, and group opera­tion (a flight of four interceptors exchanging information automatical­ly). This latter mode requires some explanation. The leader is the only aircraft linked to the ground automatic guidance network designated AK-RLDN, but it can exchange information with the other three air­craft. Each aircraft is kept 200 km (124 miles) apart. The four are there­fore lined up to cover a space 600 km (372 miles) wide; but because of their radar scanning angles (140 degrees) and the overlap of the scanned sectors, the overall zone swept by the four aircraft is 800-900 km (495-560 miles) wide.

The APD-518, a powerful digital data signaler, gives the leader and the wingmen a continuous flow of exchangeable information. All prob­lems of guidance, target identification, and coordination between inter­ceptor flights were then managed by the MiG-31’s avionics via the auto­matic data exchange between aircraft. The target allotment—just before attacking—is carried out by the flight leader according to the information provided by the tactical situation display.

The MiG-31’s armament was quite impressive:

1. Air-to-air missiles. Four long-distance (110-km [68-mile]) radar- guided R-33s under the fuselage, or four R-33s and two medium – range infrared-guided R-40Ts, or four R-33s and four short-range infrared-guided R-60TS, or two R-60s and two 2,500-1 (660-US gal­lon) drop tanks under four wing pylons. A new method of carry­ing the four bigger missiles—placing them in pairs beneath the fuselage, one behind the other—reduced drag considerably. Before firing, the missiles split off from the aircraft by means of special AKU ejecting pylons The missile’s engine is ignited and its homing device enabled once it is a safe distance out of the air­craft’s flight path.

2. Fixed armament. One Gatling-type 23-mm GSh-6-23 cannon with 260 rounds, fed by a linkless ammunition belt. The rate of fire is presently 6,000 plus-or-minus 500 rounds per minute (but should later be raised to 8,000 rounds per minute), and the initial speed is 700 meters per second (2,300 feet per second). This weapon is located on the right side of the fuselage behind the main landing gear.

The aircraft entered production in 1979 at the Gorki factory, and the first MiG-31-equipped regiments were operational by 1982 The

The simultaneous tracking and fire sectors covered plus-or minus 70 degrees in azimuth and -60 to +70 degrees in elevation.

Only four MiG-31s are needed to sweep a zone 800-900 km (495-560 miles) wide. The leader is the only aircraft linked to the ground stations, but all information can be exchanged between the four aircraft via the AFD-518 automatic data signaler.

MiG-31 project was managed by R. A Belyakov, assisted by bright team members such as G Ye. Lozino-Lozinskiy, V A Arkhipov, К К Vasilchenko, and A A Belosvyet

Specifications

Span, 13 464 m (44 ft 2 1 in), overall length, 22 688 m (74 ft 5 2 in), height, 6 15 m (20 ft 2 1 in), wing area, 61 6 m2 (663 sq ft), empty weight, 21,820 kg (48,105 lb); takeoff weight with 100% internal fuel, 41,000 kg (90 365 lb), internal fuel, 16 350 kg (36,035 lb); takeoff weight with 100% internal fuel and two 2.500-1 (660-US gal) drop tanks 46,200 kg (101,825 lb); wing loading, 665 6-750 kg/m2 (136 5-153 8 lb/sq ft); max operating limit load factor at supersonic speed 5

Performance

Max speed, 3,000 km/h at 17,500 m (1,863 kt at 57 400 ft); max speed at sea level, 1 500 km/h (810 kt); max cruising speed Mach 2.35; eco­nomical cruising speed Mach 0 85 service ceiling 20,600 m (67,570 ft); climb to 10 000 m (32 800 ft) in 7.9 mm landing speed, 280 km/h (151 kt); ferry range with 100% internal fuel and two 2,500-1 (660-US gal) drop tanks, 3,300 km (2 050 mi); max endurance with two 2,500-1 (660-US gal) drop tanks, 3 6 h; endurance with one in-flight refueling 6-7 h; radius of action at Mach 2 35, 100% internal fuel, and four R-33 missiles, 720 km (448 mi); at Mach 0.85, 100% internal fuel, and four R-33 missiles, 1,200 km (745 mi); at Mach 0 85, 100% internal fuel, four R-33 missiles, and two 2,500-1 (660-US gal) drop tanks 1,400 km (870 mi), at Mach 0 85, same conditions with one in-flight refueling 2 200 km (1,365 mi); takeoff roll at 46,200 kg (101,825 lb), 1,200 m (3,935 ft), landing roll, 800 m (2,625 ft)

The FF program was an update of the production MiG-9 or FS that boosted the engines’ thrust and reinforced the pilot’s armor protection.

The BMW 003 turbojets were retooled in factory no. 17 in Kazan. This modification was at the heart of the RD-20F, later redesignated the RD-21 and built entirely with components and accessories made in the USSR. The thrust of the hotted-up engine increased to 980 daN (1,000 kg st). The brakes were also improved, and 12-mm armor plates were installed in the front and rear of the cockpit, and the windshield front glass panel was replaced by a pane of bulletproof glass 44 mm thick. The total weight of the armor was 60 kg (132 pounds). Wheel braking was much improved. Externally very similar to the FS, the FF left the factory and made its first flight in September 1947,1. T. Ivashchenko at the controls. Tests were completed by the end of the year, and the FF was produced in small quantities with the same armament as the FS.

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, 3,471 kg (7,650 lb); takeoff weight, 5,117 kg (12,278 lb); fuel, 1,300 kg (2,865 lb); wing loading, 281.2 kg/m2 (57.6 lb/sq ft).

Performance

Max speed, 950 km/h (513 kt); climb to 5,000 m (16,400 ft) in 2.9 min; service ceiling, 13,000 m (42,640 ft).

In addition to its usual armament suite, the experimental SD-21 was fit­ted with two wing store stations for 210-mm S-21 unguided air-to-sur – face rockets. This same prototype was tested in overload conditions with two S-21 rockets and two 250-1 (66-US gallon) drop tanks.

MG-15 bis / SD-57

This modified production MiG-15 bis was developed for tests of two automatic rocket pods (each carrying twelve 57-mm ARS-57 rockets), which were attached to the store stations usually reserved for drop tanks.

MiG-15 bis / ISh

This version of the MiG-15 bis was equipped with two wing pylons that could accept either heavy rockets, automatic rocket pods (six or twelve rockets per pod), or drop tanks. Twelve of these planes were built and flight-tested at the Nil WS.

The SDK-5 was a MiG-17 modified to simulate the flight track of a winged air-to-surface missile and to test the airborne guidance equip­ment of the whole system (mother aircraft plus missile) On this proto­type all cannons were removed. Above the air intake, a small radome housed an electromagnetic detector to vector the missile/aircraft toward its target, another small radome on top of the fin housed the antenna that received radio signals—transmitted by the mother air­craft-coordinating the missile’s/’aircraft’s flight path. Similar equip­ment was mounted to a MiG-9L during development of the KS-1 cruise missile

These four modified MiG-19S were used to develop and test air-to-sur – face winged homing missiles. During flight tests the SM-20 was carried under the fuselage of a Tu-95 bomber. The pilot was in tbe fighter cockpit, but tbe engines were off. When the preselected altitude was reached, the pilot started the engines and released his airplane from the bomber. He then had to check on the operation of the radio remote control enabled by the mother aircraft and to return to his base when the test was oyer. The first SM-20 was built in 1956, and tests started in October of that year.

The second "flying simulator” or SM-20/P was built in early 1957. The aircraft was modified to help the engines start at high altitudes—a problem that had plagued the SM-20. On this version, ignition of the combustion chamber was aided by a carburetor. In all other respects the SM-20/P was identical to the SM-20. Both aircraft were flight-tested by Sultan Amet-Khan of the LII and V. G. Pavlov of the ministry of radio equipment industry research center. The chief engineer respon­sible for both programs was A. I. Vyushkov.

Two more flying simulators were tested in 1957 and 1958, the SM – K/l and SM-K/2. Both were derived from the MiG-19S and were also intended to help in the development of flight management and guid­ance systems for air-to-surface winged missiles.

The Ye-4 and Ye-5 frontline single-seat fighters were built in 1955 and 1956. Unlike the Ye-2 and Ye-2A, built at the same time, the Ye-4 and Ye-5 had a delta wing with a sweepback of 57 degrees at the leading edge. But the fuselages were identical; so because the wheel wells for the main gear were at the same place, the legs had to be modified to retract into the delta wing. That modification gave the Ye-4 and Ye-5 a slightly larger wheel track. A high degree of commonality between the two competing aircraft was to have allowed engineers to choose the wing shape for the future frontline fighter with full knowledge of the implications of their choice.

The wing profile was a TsAGl-S9s, the ailerons were axially trimmed, and the single-slotted Fowler flaps were rectangular. The air­brakes were placed beneath the fuselage—two of them near the wing root, the third hinged farther back on frame no. 28. The three sets of fuselage fuel tanks had a total capacity of 1,570 1 (414 US gallons), and the aircraft could store an additional 400 1 (106 US gallons) under the fuselage in a "supersonic" drop tank. The two NR-30 cannons (at sixty rounds per gun) flanked the lower part of the forward fuselage The shell cases were ejected, but the ammunition belts and links were col­lected in the empty part of the shell sleeves that ran across three fuse­lage sections. A pylon under the fuselage could carry either an auto­matic rocket pod (16 ARS-57) or one FAB 500 bomb. The ASP-5N gun – sight was linked to the SRD-1M Konus ranging radar. The slab tailplane was actuated by a BU-44 servo-control unit and the aileron controls were boosted by a BU-45 servo-control unit, both of the irreversible variety. The slab tailplane was fitted with the ARU-3V feel computer to modify the gear ratio between the stick and the stabilator and to con­trol the stick load according to flight speed and altitude. The ejection seat was identical to that of the MiG-19S (the curtain type). Main equip­ment included the RSIU-4V VHF, the ARK-5 automatic direction finder, and a radar warning receiver.

The last stage of the long development process that was to lead to the MiG-21, the Ye-4 was powered by the AM-9 turbojet rated at 3,185 daN (3,250 kg st with reheat). This was virtually the only thing differen­tiating this aircraft from the Ye-5. The Ye-4 arrived at the flight test cen­ter in June 1955. After the usual proceedings (weight determinations, ground roll tests, and a few “leapfrog" takeoffs) the Ye-4 was first pilot­ed by G. A Sedov on 16 June. Factory tests ended on 20 September 1956.

During these fifteen months, several methods were tested to straighten the airflow on the wing—either six fences over the upper surface (four of which protruded ahead of the leading edge) or two

The pros and cons of the delta wing approach were assessed on the Ye-4. The wing had two fences on the lower surface, but the Ye-4 has also flown with a clean wing.

On the Ye-4 with fences on the lower surface of the wing, the wing tips were markedly pointed.

On the same Ye-4, fitted this time with six fences on the wing’s upper surface, the square wing tips reduced the span by 600 millimeters (23.6 inches).

The Ye-5 retained the delta wing and upper-surface fences of the Ye-4, but the wing tips are again markedly pointed.

fences over the lower surface and an increase in wingspan (sharp wing tips). Finally a third solution was found: a chord extension on about one-third of the leading edge that formed a vortex-generating "tooth." After this modification the Ye-4 was transferred to the LI1, where it was tested a number of times at great angles of attack.

The Ye-5 was powered by the AM-ll turbojet with 3,725 daN (3,800 kg st) of dry thrust and 5,000 daN (5,100 kg st) of maximum thrust with afterburner. Its wing had six fences (four of which protruded ahead of the leading edge). It was moved to the flight test center on 10 Decem­ber 1955 and was first piloted on 9 January 1956 by V. A. Nefyedov. During a ground run-up on 20 February the engine caught fire, and the turbine was destroyed. After being repaired at the factory the Ye-5 made eight flights between 26 March and 19 May. Tests were suspend­ed once more when the turbine broke and the engine had to be removed. On 18 October the aircraft was grounded. On 27 October the AM-11 was returned to the factory to increase the volume of the after­burner, and on 24 November the nose of the fuselage was returned to the workshop to be lengthened by 400 millimeters in order to move the aircraft’s center of mass forward and increase the fuel capacity to 1,810 1 (478 US gallons). Those modifications had a strong influence on the final choice between the Ye-5’s delta wing and the Ye-2A’s sweepback wing.

The Ye-5 resumed its test schedule on 1 April 1957 and went up thirteen times before 26 May for reassessments of the aircraft’s flight envelope after the modifications to its engine and fuselage. No fewer than ten AM-11 test models and one production engine were used to complete the aircraft’s factory tests. According to the test pilot, the Ye-5 cockpit was roomier than that of the MiG-19, and the approach and landing procedures of both aircraft were quite similar. Extension of the gear had no effect on the aircraft’s trim characteristics. There was no change in the longitudinal trim anywhere in its flight envelope, and it was easier to fly than the MiG-19 at supersonic speeds. The forward movement of the cone ahead of the air intake plane was automatic from Mach 1.4 upward.

The factory tests of the Ye-5 or MiG-21 came to a close without major problems. All of its design parameters were met except for the range, which fell short because of the excessive specific fuel consump­tion of the engine that was renamed the R-l 1. Altogether seven Ye-5s were built, two prototypes and five preproduction machines.

The following details refer to the Ye-4

Specifications

Span, 7.749 m (25 ft 5 in); fuselage length (except cone), 11.737 m (38 ft 6.1 in); wheel track, 2.692 m (8 ft 10 in); wheel base, 4.48 m (14 ft 8.4 in); wing area, 23.13 m2 (248.9 sq ft); takeoff weight, 5,200 kg (11,465 lb), fuel, 1,300 kg (2,865 lb); wing loading, 224.8 kg/m2 (46.03 lb/sq ft).

Performance

Max speed, 1,970 km/h (1,064 kt); climb to 5,000 m (16,400 ft) in 1.6 min; service ceiling, 16,400 m (53,800 ft); range in clean configuration, 1,120 km (695 mi).

The following details refer to the Ye-5.

Specifications

Span, 7.749 m (25 ft 5 in); fuselage length (except cone), 11.93 m (37 ft 2 in); wheel track, 2.692 m (8 ft 10 in); wheel base, 4.48 m (14 ft 8.4 in); wing area, 23.13 m2 (248.9 sq ft); takeoff weight, 5,700 kg (12,565 lb); fuel, 1,500 kg (3,305 lb); wing loading, 246.4 kg/m2 (50.47 lb/sq ft).

Performance

Max speed, 1,970 km/h (1,064 kt); climb to 5,000 m (16,400 ft) in 0.6 min; service ceiling, 17,650 m (57,900 ft); range, 1,330 km (825 mi), takeoff roll, 730 m (2,395 ft); landing roll, 890 m (2,920 ft).

As its appellation suggests, the MiG-21 MT was also a modified MiG – 21M. But the letter t (for toplivo fuel) indicated that the aircraft’s fuel capacity had increased significantly, from 2,650 1 (700 US gallons) to

3,250 1 (858 US gallons). All the fuel for the uplift was held in the long dorsal fairing from the back of the cockpit to the base of the tail fin; this space contained a remarkable 900 1 (238 US gallons) of fuel. The capacity of this segment was later reduced to 600 1 (159 US gallons), cutting the aircraft’s total fuel capacity to 2,9501 (779 US gallons).

The aircraft was powered by the R-13F-300 turbojet capable of 6,360 daN (6,490 kg st). Its armament and radar were identical to those of the MiG-2 IMF. The MiG-21MT was only a transitional aircraft, and only fifteen copies were built in 197] in the MMZ Znamya Truda facto­ry in Moscow. Five were allocated to the pilots of the WS service eval­uation department.

Specifications

Span, 7.154 m (23 ft 5.7 in); fuselage length (except cone), 12.285 m (40 ft 3.7 in); wheel track, 2.787 m (9 ft 1.7 in); wheel base, 4.71 m (15 ft 5.4 in); wing area, 23 m2 (247.6 sq ft); takeoff weight, 8,800 kg (19,395 lb); fuel, 2,700 kg (5,950 lb); wing loading, 382.6 kg/m2 (78.4 lb/sq ft); max operating limit load factor, 8.5.

Performance

Max speed, 2,175 km/h at 13,000 m (1,175 kt at 42,640 ft); max speed at sea level, 1,300 km/h (702 kt); climb rate at sea level in clean con­figuration, 150 m/sec (29,530 ft/min); climb to 16,800 m (55,100 ft) in 9 min; service ceiling, 17,300 m (56,745 ft); range, 1,300 km (810 mi); with 800-1 (211-US gal) drop tank, 1,670 km (1,035 mi); takeoff roll, 900 m (2,950 ft); landing roll with SPS and tail chute, 550 m (1,800 ft).