Mikoyan-Gurevich MiG-17 - Development

Development

While the MiG-15bis would be destined to introduce swept wings to air combat over Korea, by 1949, the Mikoyan-Gurevich design bureau had already begun work on its replacement, originally the MiG-15bis45, which would fix any problems found with the MiG-15 in combat. The result was one of the most successful transonic fighters introduced before the advent of true supersonic types such as the Mikoyan-Gurevich MiG-19 and North American F-100 Super Sabre. The design would ultimately still prove effective into the 1960s when pressed into dogfights over Vietnam against supersonic types which were generally flown at subsonic speeds, and not optimized for subsonic maneuvering short-range engagements.

While the MiG-15 used a Mach sensor to deploy airbrakes because it could not safely exceed Mach 0.92, the MiG-17 was designed to be controllable at higher Mach numbers. Early versions which retained the original Soviet copy of the Rolls-Royce Nene VK-1 engine were heavier with equal thrust. Later MiG-17s would be the first Soviet fighter application of an afterburner which offered increased thrust on demand by dumping fuel in the exhaust of the basic engine.

Though the MiG-17 still strongly resembles its forebear, it had an entirely new thinner and more highly swept wing and tailplane for speeds approaching Mach 1. While the F-86 introduced the "all-flying" tailplane which helped controllability near the speed of sound, this would not be adopted on MiGs until the fully supersonic MiG-19. The wing had a "sickle sweep" compound shape with a 45° angle like the U.S. F-100 Super Sabre near the fuselage (and tailplane), and a 42° angle for the outboard part of the wings. The stiffer wing resisted the tendency to bend its wingtips and lose aerodynamic symmetry unexpectedly at high speeds and wing loads.

Other easily visible differences to its predecessor were the three wing-fences on each wing, instead of the MiG-15's two, the addition of a ventral fin and a longer and less tapered rear fuselage that added about 3 feet in length. The MiG-17 shared the same Klimov VK-1 engine and much of the rest of its construction such as the forward fuselage, landing gear and gun installation was carried over. The first prototype, designated I-330 "SI" by the construction bureau, was flown on the 14 January 1950, piloted by Ivan Ivashchenko.

In the midst of testing, pilot Ivashchenko was killed when his aircraft developed flutter which tore off his horizontal tail, causing a spin and crash on 17 March 1950. Lack of wing stiffness also resulted in aileron reversal which was discovered and fixed. Construction and tests of additional prototypes "SI-2" and experimental series aircraft "SI-02" and "SI-01" in 1951, were generally successful. On 1 September 1951, the aircraft was accepted for production, and formally given its own MiG-17 designation after so many changes from the original MiG-15. It was estimated that with the same engine as the MiG-15's, the MiG-17's maximum speed is higher by 40–50 km/h, and the fighter has greater manoeuvrability at high altitude.

Serial production started in August 1951, but large quantity production was delayed in favor of producing more MiG-15s so it was never introduced in the Korean War. It did not enter service until October 1952, when the MiG-19 was almost ready to be flight tested. During production, the aircraft was improved and modified several times. The basic MiG-17 was a general-purpose day fighter, armed with three cannons, one Nudelman N-37 37mm cannon and two 23mm with 80 rounds per gun, 160 rounds total. It could also act as a fighter-bomber, but its bombload was considered light relative to other aircraft of the time, and it usually carried additional fuel tanks instead of bombs.

Although a canopy which provided clear vision to the rear necessary for dogfighting like the F-86 was designed, production MiG-17Fs got a cheaper rear-view periscope which would still appear on Soviet fighters as late as the MiG-23. By 1953, pilots got safer ejection seats with protective face curtain and leg restraints like the Martin-Baker seats in the west. The MiG-15 had suffered for its lack of a radar gunsight, but in 1951, Soviet engineers obtained a captured F-86 Sabre from Korea and they copied the optical gunsight and SRD-3 gun ranging radar to produce the ASP-4N gunsight and SRC-3 radar. The combination would prove deadly over the skies of Vietnam against aircraft such as the F-4 Phantom whose pilots lamented that guns and radar gunsights had been omitted as obsolescent.

The second prototype variant, "SP-2" (dubbed "Fresco A" by NATO), was an interceptor equipped with a radar. Soon a number of MiG-17P ("Fresco B") all-weather fighters were produced with the Izumrud radar and front air intake modifications.

In early 1953 the MiG-17F day fighter entered production. The "F" indicated it was fitted with the VK-1F engine with an afterburner by modifying the rear fuselage with a new convergent-divergent nozzle and fuel system. The afterburner doubled the rate of climb and greatly improved vertical maneuvers. But while the plane was not designed to be supersonic, skilled pilots could just dash to supersonic speed in a shallow dive, although the aircraft would often pitch up just short of Mach 1. This became the most popular variant of the MiG-17. The next mass-produced variant, MiG-17PF ("Fresco D") incorporated a more powerful Izumrud RP-2 radar, though they were still dependent on Ground Control Interception to find and be directed to targets. In 1956 a small series (47 aircraft) was converted to the MiG-17PM standard (also known as PFU) with four first-generation Kaliningrad K-5 (NATO reporting name AA-1 'Alkali') air-to-air missiles. A small series of MiG-17R reconnaissance aircraft were built with VK-1F engine (after first being tested with the VK-5F engine).

Over 6,000 MiG-17s were built in the USSR by 1958. Another 2,000 were built under licence in Poland and China.

The next development, the MiG-19 was yet another derivative intended to reach supersonic speeds in level flight. The first prototype I-350 was based on the MiG-17 with an even greater wing and tail sweepback of 60 degrees, though the finalized design would look quite different from the original MiG-15.