to –6g). Many Z-50L and LA versions were rebuilt to Z-50LS standard in the early 1980s. A Z-50LS won the World Aerobatic Championships in 1984 and 1986, but the debut of the Sukhoi Su-26 in the 1986 eventually edged out the Zlin from world-class competition. Another version derived from the Zlin Z-50 aircraft is a "baby fifty" – Z-50M with a LOM M137AZ engine of 134 kW (180 HP). This was introduced as a replacement for the Z-526, which was often converted to N (normal) category and used as a glider tug at aero clubs. The Z-50M has limit maneuvering load factors of +7 and -5,5. Only five Z-50M aircraft were built. In April 1990 a Z-50LS received modified wings and was evaluated to determine if maneuvrability was improved. The plane was designated Z-50LE (Experimental). This unit remained as a prototype and is currently in Moravska Trebova, at the Czech air school. The last version of Zlin 50 is the Z-50LX, which first flew in 1991, piloted by Zlin chief pilot Vladmir Peroutka. This version received additional fuel tanks in the wings and a robust smoke system for airshow routines; it was produced principally at the urging of show pilot Victor Norman. From 1992 to 1995 seven Z-50LX were built, and four of them are used by the Red Bull Flying Bulls Aerobatics Team led by Radka Máchová. Z-50LS are still in use; the Polish Aerobatic Team Zelazny uses 3 of them. Variants Z-50L First production variant with a Lycoming AEIO-540-D4B5 engine, certified in 1977, conversion to 50LA and 50LS variants, 25 built. (0001-0025) Z-50LA Variant certified in 1980, five built and 18 conversions from Z-50L. Z-50LS Variant certified in 1982 with a Lycoming AEIO-540-L1B5D engine, 34 built and 18 converted from Z-50, one aircraft was rebuilt as a Z-50M and two as Z-50LX. Z-50LX Variant certified in 1991 with a Lycoming AEIO-540-L1B5D engine, nine built with two converted from Z-50LS, two were rebuilt as Z-50LS. Z-50M Variant certified in 1989 with a LOM M 137 AZ engine, six built and one conversion. Specifications (Z-50L) References Firth, John. US wins world aerobatics". Flight International, 20 September 1980. p. 1183 Frazer, Jeanne. "Czechs are world aerobatic champions". Flight International, 23 September 1978. pp. 1156–7 Mondey, David. Encyclopedia of The World's Commercial and Private Aircraft, Zlin Z 50 L (p. 248). Crescent Books, New York NY (1981) Postlethwaite, Alan. "Czech flights". Flight