Lim-6

The Lim-6 was a Polish attack aircraft, a variant of Mikoyan-Gurevich MiG-17 (NATO reporting name Fresco).

Development

In 1955 Poland bought a licence for manufacturing the Soviet fighter aircraft, the MiG-17, being the basic jet fighter of Warsaw Pact countries. It was given a designation Lim-5 in Poland (an abbreviation of: licencyjny myśliwiec – "licence fighter"). The first Lim-5 was built in WSK-Mielec on November 28, 1956, replacing in production Lim-2 (MiG-15bis). By production's end in 1960, 477 Lim-5's were built, becoming Polish basic fighter (serial numbers: 1C 00–01 to 1C 19–14). In this number, there was also a number of reconnaissance variant Lim-5R, with AFA-39 camera. From 1959 there was produced also a licence interceptor MiG-17PF, equipped with the Izumrud-5 (RP-5) radar, named Lim-5P. By 1960, 129 were built (serial numbers to 1D 06–41).

As soon, as in the late 1950s, there started works in Poland to develop a light attack aircraft basing on the Lim-5. The basic MiG-17 and Lim-5 could carry only two bombs 250 kg, instead of underwing fuel tanks. Ater building some prototypes, designated 'CM', in 1960 started production of an attack aircraft Lim-5M. It introduced several modifications to a fighter, mostly in order to enable basing on ground airfields. It had double undercarriage wheels, braking parachute and attachments for RATO. Most noticeable were additional fuel tanks in thicker wing sections close to the fuselage. Instead of two bombs, it could carry two launchers for eight 57 mm rockets S-5. By 1961, 60 Lim-5M's were built and from November 1961 given to the Polish Air Force (serial numbers: 1F 01–01 to 1F 03–30). They were not succesfull; thicker wings with fuel tanks decreased their performance and made flying tricky, while the range was not increased due to drag. The Lim-5M was regarded only as an interim variant, and works upon more advanced plane continued, testing many different ideas. In 1961, 40 attack aircraft Lim-6 were built (serial numbers: 1J 04–01 to 1J 04–40). They introduced new blown flaps, but tests showed problems with the modified Lis-6 jet engine and the aircraft were not given to the Air Force. As a result, it was decided to resign of thick wing sections with fuel tanks, blown flaps, double wheels and RATO and return to only slightly modified Lim-5 construction.

The Lim-6bis

In 1963 started production of the final variant of an attack plane, Lim-6bis. It had standard wings and single wheels, like Lim-5 fighter. Most important change was adding two underwing weapon pylons, close to the fuselage. Other change was adding a braking parachute container below a rudder. From 1963, these aircraft started equipping the Polish Air Force, but it was officially accepted only on September 14, 1964.

By 1964, there were built 70 Lim-6bis (numbers 1J 05–01 to 1J 06–40), and a number of aircraft were rebuilt of Lim-5M and Lim-6 to Lim-6bis standard. A number were made in a reconnaissance variant Lim-6R (or Lim-6bisR) with AFA-39 camera under a fuselage.

As Lim-5P fighters became obsolete, from 1971 they were also rebuilt to Lim-6bis standard, designated Lim-6M. Radars were removed from them, but there remained radar covers in central air intake. They were fitted with additional underwing pylons, but not with a braking parachute. Some aircraft were modified to a reconnaissance variant Lim-6MR.

Lim-6bis, 6R, 6M and 6MR were used by the Polish Air Force, as most numerous attack aircraft, until the 1980s. They were finally withdrawn in 1992.

Reportedly some were exported to GDR, Egypt and Indonesia

Armament

The Lim-6bis was armed with two NR-23 23 mm cannons (80 rounds) and one N-37D 37 mm cannon (40 rounds), like MiG-17 (the Lim-6M was probably armed with three NR-23 23 mm cannons, like MiG-17PF). It had four underwing pylons. Typical armament were two launchers Mars-2 (Polish-made) for 16 unguided 57 mm rockets S-5 each, or 100 kg bombs. It could also carry 250 kg bombs or launchers on standard outer underwing pods, but usually they were used for 400l fuel tanks.

Specifications (Lim-6bis)

General Characteristics

• Crew: One
• Length : 11.36 m ( ft in)
• Wing Span : 9.628 m ( ft in)
• Height : 3.80 m (12 ft 5.5 in)
• Wing area: ft² ( m²)
• Empty: 4271 kg ( lb)
• Loaded: 5651 kg
• Maximum takeoff: 6652 kg ( lb)
• Engine : One 33.1 kN (7,452 lbf) thrust Lis-5 (licence Klimov VK-1F) turbojet

Performance

• Maximum Speed : 1150 km/h
• Range : 1080 km (without additional tanks)
• Service Ceiling : 16,470 m (with afterburner)
• Rate of climb: ft/min ( m/min)
• Wing loading: lb/ft² ( kg/m²)
• Thrust-to-weight:

Armament

• One 37-mm N-37D cannon (40 rds)
• Two 23-mm NR-23 cannon (80 rds each)
• 780 kg of bombs, rocket launchers or napalm tanks on 4 pylons

Related content

Related development: MiG-17 - Shenyang J-5

Comparable aircraft: F-86D Sabre

Designation sequence: Lim-1 - Lim-2 - Lim-5 - Lim-6

External links

• article in Polish with photos in Wiraże 2/2004