Category Mig

PBSh-1

Throughout the 1930s the doctrines relating to the use of big armored units were completely reappraised. Because every new threat demand­ed an immediate answer, a new type of aircraft appeared in the USSR: the shturmovik, or assault aircraft. Several of the best-known aircraft manufacturers worked on this new weapon. At the start of the decade Tupolev proposed two heavy shturmoviks, the ANT-17 and ANT-18, but they were never built. The TsKB (central construction bureau) built four aircraft designed by D. P. Grigorovich, the LSh-1, TSh-1, TSh-

2, and ShON. In 1933 a design brigade under the leadership of S. A. Kocherigin—and assisted by the forty-one-year-old M. I. Guryevich, Mikoyan’s future right-hand man—built the TSh-3, also called the TsKB-4. N. N. Polikarpov, for its part, developed the R-ZSh.

All of these attempts led in 1936 to the Ivanov program (“Ivanov” was Stalin’s cable address), an air force initiative that resulted in the construction of such prototypes as the KhAI-5 (R-10) and KhAI-52, designed by Nyeman, winner of the contest; and the ANT-51 and ShB, both designed by Sukhoi. But in the end the true winner was a relative­ly unknown outsider, S. V. Ilyushin. More than 40,000 of its BSh-2s, renamed the 11-2 in 1940, were built because of the war.

Mikoyan and Guryevich started the preliminary design of their first assault aircraft in 1940. The PBSh-1 (Pushechniy Bronirovaniy Shtur – movik. armored assault aircraft with cannons) was a single-seater designed to attack frontline ground targets such as troops, strong points, and armored vehicles. It had a cantilever inverted gull wing and was to be powered by a 1,178 kW (1,600 ch) Mikulin AM-38 engine. Sensitive parts, the engine, and the cockpit would be protected by armor plating. But the weight of the armor alone was 1,390 kg (3,065 pounds), or 30 percent of the aircraft’s takeoff weight. The design had tc be completely reconsidered to integrate the armor into the stressed structure. It was to be equipped with two 23-mm cannons in fairings beneath the wing (96 rpg) and six 7.62-mm ShKAS machine guns on the wing leading edge (750 rpg). All of these weapons would fire out­side the propeller disc.

The bomber version of the aircraft was to carry in its fuselage either 24 10-kg (22-pound) FAB-10 or 24 8-kg (17.6-pound) FAB-8 bombs and either 280 2.5-kg (5.5-pound) FAB-2.5 or 120 1-kg (2.2-pound) ZAB – 1 bombs. (FAB indicates demolition bombs, while ZAB refers to incen­diary bombs. The number after the acronym reflects the bomb’s weight.) For dive-bombing missions, two FABs ranging in weight from 25 to 250 kg (55 to 550 pounds) could be added beneath the wings.

The preliminary design by N. Z. Matyuk, chief of the aerodynamic design department, was approved on 24 July 1940 by OKO chief engi­neer Mikoyan, his assistant Guryevich, and P. V. Dementyev, manager of Aviakhim factory no. 1. The OKO started work on a full-scale model of the aircraft in the fall. But as soon as the Ilyushin 11-2 was approved for series production, О KB engineers halted all work on the PBSh-1 and started in immediately on the preliminary design for the PBSh-2.

In some OKB documents the PBSh-1 is referred to as the MiG-4.

Specifications

Span, 13.5 m (44 ft 3.5 in); length, 10.145 m (33 ft 3.4 in); height, 3.2 m (10 ft 6 in); wheel track, 2.9 m (9 ft 10 in); wheel base, 6.6 m (21 ft 7.9 in); wing area, 30.5 rrF (328.3 sq ft); takeoff weight, 4,850 kg (10,690 lb); max takeoff weight, 6,024 kg (13,277 lb); wing loading, 159 kg/m2 (32.6 lb/sq ft).

Design Performance

Max speed, 441 km/h at 5,000 m (238 kt at 16,400 ft); max ground speed, 449 km/h (242 kt); range, 900 km (560 mi); service ceiling, 7,600 m (25,690 ft).

A note came with the PBSh-2 preliminary design created by the factory no. 1 OKO in July 1940. It said: "Considering that hedge-hopping flying in a highly wing-loaded aircraft is rather demanding and moreover that monoplanes seldom forgive pilots’ mistakes at very low altitudes, we have chosen the biplane configuration for the PBSh-2, even though it has been designed to carry out the same missions as the PBSh-1. Biplanes are much easier to fly. They have far better stability and maneuverability."

The PBSh-2 silhouette was quite unusual. Areas of the two wings of this biplane were quite different. The smaller upper wing had a for­ward sweep angle of 12 degrees and no ailerons. A light dihedral was applied to the lower wing outer panels. The whole trailing edge was

The unorthodox PBSh-2 was no more successful than the PBSh-1. The VVS chose instead the Ilyushin shturmovik, the 11-2.

occupied by large ailerons and two-segment flaps. The wings were braced by I-type struts.

Like the PBSh-1, the engine was to be a 1,178 kW (1,600 ch) AM-38 protected (along with the fuel tanks and cockpit) by case-hardening homogenized armor plates whose thickness varied from 7.5 to 15.5 mm. The planned armament was similar to that of the PBSh-1: two 23- mm cannons and six 7.62-mm machine guns.

The center section of the lower wing contained two bays for 1- to 10-kg (2.2- to 22-pound) bombs. As with the PBSh-1, the 25- to 250-kg (65- to 550-pound) bombs were strapped beneath the wings for dive – bombing missions, whatever the diving angle might be. But because 11- 2 production was stepped up at several factories, all work on the PBSh – 2 stopped by the end of 1940.

In some OKB documents the PBSh-2 is referred to as the MiG-6.

Specifications

Span, 8.6/12.4 m (28 ft 2.6 in/40 ft 8.2 in); length, 8.85 m (29 ft 0.4 in); height, 3.5 m (11 ft 5.8 in); wheel track, 2.97 m (9 ft 8.9 in); wheel base, 5.23 m (17 ft 1.9 in); wing area, 10.26/22.14 m2 (110.44/238.3 sq ft); takeoff weight, 4,828 kg (10,641 lb); wing loading, 149 kg/m2 (30.5 lb/sq ft).

Design Performance

Max speed at sea level, 426 km/h (230 kt); range, 740 km (460 mi); range with two 100-1 (26.4-US gal) auxiliary tanks, 929 km (577 mi).

DIS 200/Т

At the end of the 1930s the VVS could operate a fleet of long-range heavy bombers and tactical medium-range bombers but did not have the escort fighters needed to protect them. As early as 1940, the newly formed design bureau had tackled the development of a long-range escort fighter capable of performing high-speed reconnaissance, light bombing, and torpedoing roles. In the preliminary design it was planned to use new, efficient diesel engines developed by A. D. Charomskii, the M-40 and M-30, which would give the aircraft a much greater range because of their low specific fuel consumption.

But neither of these diesels were as yet reliable, so it was decided to equip the prototype—whose factory code letter was T—with two liq­uid-cooled in-line 1,030 kW (1,400 ch) AM-37s driving three-bladed vari­able-pitch propellers. The exhaust collectors were bent and extended above the wing upper surface. Fuel was distributed into six tanks, four in the wing center section and two behind the cockpit. Two oil coolers were located on each side of the engine cowlings as on the MiG-3. The glycol was cooled by two air scoops placed on each side of the cowl­ings, and the corresponding outlets were located beneath the trailing

edge of the wing. The engine supercharger inlets were located in the leading edge.

The single-seat, twin-engine T prototype had a low wing, a twin fin configuration, and a structure composed primarily of wood rather than scarce light alloys. The flight tests led to the installation of slats on the wing leading edge. On the trailing edge, to complement the two-seg­ment flaps, high lift was augmented by specially designed ailerons, which could be symmetrically lowered to 20 degrees. The latter feature was a great novelty at the time; today they are known as flaperons. The main gear (950 x 300 tires) retracted into the engine nacelles and the tail wheel into the fuselage, and both were pneumatically operated—a first in the USSR.

The cockpit was equipped for instrument flying, and the pilot had an oxygen dispenser and a radio receiver at his disposal. The sliding aft canopy could be jettisoned. The front, rear, sides, and underside of pilot’s seat were protected by armored plates, and the lower part of the fuselage nose was glazed to give the pilot some downward vision.

The DIS-200 T fighter variant was especially powerful, with one 23- mm VYa cannon in a removable fairing under the nose to complement two 12.7-mm BS and four 7.62-mm ShKAS machine guns on the leading edge of the wing. The cannon fairing could be replaced by a 1,000-kg (2,200-pound) bomb or a torpedo.

The T started its taxiing tests on 15 May 1941 and made its first flight at the end of the month, with A. I. Zhukov at the controls. Flight tests went on all summer at the Khodinka airfield near Moscow and were conducted by Zhukov and V. N. Savkin, an Nil WS test pilot.

Series production of the T was to have taken place at factory no. 1, but the Germans invaded just as the first tests got under way. The air­craft was moved to Kazan, and flight tests were not continued.

In some OKB documents the fighter version is referred to as the MiG-5 and the bomber version as the MiG-2. DIS stands for Dalniy Istrebityel Soprovozhdeniya: long-range escort fighter. The DIS-200 had three competitors: the Tairov Ta-3 (OKO-6bis), the Polikarpov TIS, and the Grushin Gr-1.

Specifications

Span, 15.1 m (49 ft 6.5 in); length, 10.875 m (35 ft 8.1 in); wheel track, 4.6 m (15 ft 1.1 in); wing area, 38.9 m2 (418.7 sq ft); empty weight, 6,140 kg (13,530 lb); takeoff weight, 8,060 kg (17,765 lb); fuel, 1,920 kg (4,230 lb); wing loading, 207.2 kg/m2 (42.4 lb/sq ft).

Performance

Max speed, 610 km/h at 6,800 m (329 kt at 22,300 ft); service ceiling, 10,800 m (35,425 ft); range, 2,280 km (1,415 mi); endurance, 5 h; climb to 5,000 m (16,400 ft) in 5.5 min.

Because neither Charomskii diesels nor Mikulin AM-37 engines were ready for use, the DIS-200 second prototype was powered by an M-82F, a mass-produced radial engine that could afford 1,250 kW (1,700 ch) at takeoff and 957 kW (1,300 ch) at 6,500 m (21,300 feet). The aircraft – built in Kuybyshev, where factory no. 1 and the OKB had relocated in October 1941 — was first called the IT (factory code).

Both T and IT prototypes had the same structure. The only differ­ence, except for the engines, concerned the heavier armament: four 7.62-mm ShKAS and two 12.7-mm BS machine guns plus two 23-mm VYa-23 cannons. The T could carry either a 1,000-kg (2,200-pound) bomb or a torpedo of the same weight, depending on mission require­ments. The IT rolled out of the factory in January 1942 and made its first flight later that month with G. M. Shiyakov (an LII pilot) at the controls. It was then transferred from Kuybyshev to Kazan, where it was test-flown. Meanwhile, the experience of the war demonstrated that escort missions could be handled successfully by frontal fighters, making the development of a special type of aircraft unnecessary. The IT flight tests were consequently terminated.

Specifications

Span, 15.1 m (49 ft 6.5 in); length, 12.14 m (39 ft 9.9 in); height, 3.4 m (11 ft 1.8 in); wheel track, 4.6 m (15 ft 1.1 in); wing area, 38.9 m2 (418.7 sq ft); takeoff weight, 8,000 kg (17,630 lh); fuel, 1,920 kg (4,230 lb); wing loading, 205.7 kg/m2 (42.11 lb/sq ft).

Performance

Max speed, 604 km/h at 5,000 m (326 kt at 16,400 ft); climb to 5,000 m (16,400 ft) in 6.3 min; service ceiling, 9,800 m (32,140 ft); range, 2,500 km (1,550 mi).