like the Lim-5 fighter. One important change was the addition of two underwing weapon pylons close to the fuselage. Another was the fitting of a braking parachute container below the rudder. These aircraft entered the service in the Polish Air Force in 1963, but were not officially accepted until 14 September 1964. By 1964, 70 Lim-6bis were built and a number of Lim-5Ms and Lim-6s were rebuilt as Lim-6bis. A number were also converted to a reconnaissance variant Lim-6R (or Lim-6bisR) with an AFA-39 camera under a fuselage. As Lim-5P fighters became obsolete, from 1971 they were also converted to the Lim-6bis standard, under the designation of Lim-6M. Their radars were removed, but the radar covers in the central air intake remained. They were fitted with additional underwing pylons, but not with a braking parachute. Some aircraft were modified to a reconnaissance variant designated the Lim-6MR. Design The Lim-6bis was armed with two NR-23 23 mm cannons (80 rounds) and one N-37D 37 mm cannon (40 rounds), like the 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 consisted of two Polish-made Mars-2 launchers 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. Operational history Lim-6bis, 6R, 6M and 6MR were used by the Polish Air Force as its most numerous attack aircraft until the 1980s. The last were finally withdrawn in 1992. Some were exported to the East Germany (German Democratic Republic), Egypt and Indonesia. Some GDR machines found themselves in Guinea-Bissau in the 1980s. Variants Lim-5 Day-fighter (licensed MiG-17F) (serial numbers: 1C 00-01 to 1C 19-14). Lim-5R Reconnaissance version of Lim-5. Lim-5P All-weather interceptor (licensed MiG-17PF) (serial numbers: 1D 00-01(?) to 1D 06-41). Lim-5M Attack aircraft (serial numbers: 1F 01-01 to 1F 03-30). Lim-6 Experimental attack aircraft (serial numbers: 1J 04-01 to 1J 04-40). Lim-6bis Basic attack aircraft (numbers 1J 05-01 to 1J 06-40). Lim-6R (Lim-6bisR) Reconnaissance variant of Lim-6bis. Lim-6M Interceptor aircraft, conversion of Lim-5P. Lim-6MR Reconnaissance aircraft, conversion of Lim-5P. Operators Current Operators Guinea-Bissau Air Force: In storage. Former Operators Bulgarian Air Force: 29 Lim-5, 2 Lim-5P Egyptian Air Force East German Air Force: 120 Lim-5, 40 Lim-5P All scrapped or sold to Guinea Bissau. Indonesian Air Force: