The Lim-6 (NATO reporting name Fresco) was a Polish attack aircraft used between 1961 and 1992 by the Polish Air Force. It was a variant of the Mikoyan-Gurevich MiG-17, which was produced in Poland as the Lim-5. Development In 1955 Poland bought a licence for the manufacturing of the Soviet MiG-17, the basic jet fighter of Warsaw Pact countries. The licensed aircraft was given the designation Lim-5 (an abbreviation of: licencyjny myśliwiec – "licensed fighter"). The first Lim-5 was built in WSK-Mielec on November 28, 1956, replacing the production of the Lim-2 (MiG-15bis). By production's end in 1960, 477 Lim-5s were built, becoming Poland's primary fighter. (This number includes the Lim-5R reconnaissance variant, equipped with an AFA-39 camera.) From 1959 Poland began to produce the licensed MiG-17PF interceptor, equipped with the Izumrud-5 (RP-5) radar, as the Lim-5P. By 1960, 129 were built. In the late 1950s work commenced in Poland on developing a light attack aircraft based on the Lim-5. The basic MiG-17 and Lim-5 could only carry two 250 kg bombs, which replaced their underwing fuel tanks. After building prototypes, designated 'CM', in 1960 Poles began production of an attack aircraft, Lim-5M. It introduced several modifications, mostly to allow use from rough airfields. It had double undercarriage wheels, a braking parachute, and attachments for RATO. The wing sections close to the fuselage were noticeably thicker, due to them containing additional fuel tanks. Instead of two bombs, it could carry two launchers for eight S-5 rockets (57 mm). By 1961, 60 Lim-5M's were built and from November 1961 operated by the Polish Air Force. They were not successful; thicker wings decreased performance, made handling tricky, and increased drag so much that the range was improved much less than planned. The Lim-5M was regarded only as an interim variant, and work on a more advanced design continued, testing many different ideas. In 1961, 40 Lim-6 attack aircraft were built. They introduced new blown flaps, but tests showed problems with the modified Lis-6 jet engine and the aircraft were not delivered to the Air Force. As a result, it was decided to redesign the thick wing sections with fuel tanks, blown flaps, double wheels and RATO and return to only slightly modified Lim-5 construction, with increased weapon-carrying capability instead. In 1963 the Poles started production of the final variant of the attack plane, the Lim-6bis. It had standard wings and single wheels,