The need for a sub-sonic speed required the adoption of a swept wing, and the design team was able to draw on the expertise of Gurevich himself and additional work made by Russian and German engineers. A swept-forward wing configuration was examined but it was quickly discarded in favour of the swept back configuration. It was designed around the RD-10A turbojet engine of 2205lb of thrust, which was based on the German Junkers Jumo 004. However, as the Soviet authorities signed a commercial deal with the United Kingdom, they received the next year 25 Rolls-Royce Nene engines, which was more attractive and was reverse-engineered by Klimov design bureau and was called RD-45. The original imported Nene engines powered all three of the I-310 exemplars.
The layout of the fuselage involved air fed from a bifurcated nose intake via four ducts which passed either side of the cockpit and then over and under the unbroken wing centre section. The wing was swept back at 35 degrees at the leading edge and was built up from two main spars skinned with light alloy. The upper surfaces had two full chord fences on each sides and large Fowler flaps, set at 20 degrees for takeoff and 55 degrees for landing and were attached to the wing, just forward of the trailing edge. The ailerons were the only power-operated aerodynamic controls.
The circular-section fuselage was built in two halves which could be separated by quick-release bolts at the attachment point of the rear-wing spar, leaving the whole engine exposed for maintenance purposes. Air brakes were fitted to both sides of the rear fuselage and tailplane was swept back by 40 degrees and its incidence could be adjusted manually before takeoff. It had also two secondary fuel tanks in the rear fuselage with a capacity of 90 litres (19.8 imp. gal.) each, but the main one was contained in a 1225 litre (269 imp. gal.) fitted between the wing spars. The undercarriage was made wide on purpose to make it able to operate from rough airfields and the levered-suspension mainwheels retracted inwards to lie within the fork of the front main spar.
Avionics for navigation, communications and fire control, shined for its simplicity and correctness when it was tested in combat. A gyro gunsight ,which was copied from the British GGS Mk.2, had a maximum range of 800m was used to aim the two 23mm NS-23KM cannons mounted under the nose. That weapon layout was later replaced with a single 37mm N-37 cannon on the right hand side and a pair of NS-23KM on the left. The wing hardpoints were strengthned to carry up to 500kg (1102lb) of bombs, mounted weapons, rockets or, as it became more usual, auxiliary external fuel tanks.
The I-310 was the first prototype of the MiG-15, designated S-1, and made its maiden flight some time in July 1947 and crashed during low-speed trials. To fix that error many small changes were made like installing wing fences and many changes to the back end. The second, more refined prototype flew for the first time on 30 December 1947, just two months after the prototype of the F-86 Sabre. It showed an exceptional performance reaching 1042 Km. per hour (647mph) at 3000m (9800ft) high and, in March 1948, the I-310 was cleared for mass production under the designation of Mikoyan-Gurevich MiG-15.
Sources:
1. http://all-aero.com/index.php/home2/6774-mikoyan-gurevich-mig-15--i-310
2. https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-15
3. https://forum.valka.cz/topic/view/808/Mikojan-Gurevic-I-310
4. Salamander Books - The Complete Book of Fighters
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