The Z-50L is a cantilever low-winged single-engine monoplane with a fixed tailwheel undercarriage. Unlike the Zlín Z 26 series which it replaced, the Z-50 was of all-metal construction, with limit manoeuvring load factors of +9.0 and -6.0 g’s. It hasn’t got landing flaps but in their place, two-section ailerons extend the full wingspan, providing an exceptional rate of roll. The designers made ample provision for trimming: automatic trim tabs are used on the inboard aileron sections on one of the elevators and on the fabric-covered rudder. One aileron has a ground-adjustable trim tab; the elevator has a trim tab which can be adjusted in-flight.
The standard fuel capacity can be supplemented by wingtip auxiliary tanks for ferry flights. The bubble canopy has very good visibility can be jettisoned in-flight if the need arises .
Late in 1973 a design team headed by Jan Mikula , a noted Czech designer decided to develop a new single seat aerobatic airplane. During the design phase, computer optimization was used to achieve the desired aerodynamic characteristics. The principal goal was to determine the optimum engine and propeller combination for this aircraft. Designers settled on the Lycoming AIO-540 D4B5 horizontally-opposed six-cylinder piston engine, rated at 260 hp, driving a three-blade Hoffmann constant speed propeller. On the 18 July 1975 less than two years later the prototype Zlín Z-50L (L for its Lycoming engine), with civil registration OK-070, took to the Czechoslovakian skyforits maiden flight , the first flights were very successful.
The Zlín Z 50 made its competition debut at the 1976 World Aerobatic Championships, being flown by both the Czechoslovak and Polish teams, with a Czechoslovak Z-50 finishing in third place (behind two Soviet-flown Yakovlev Yak-50s), while the Czechoslovak team finished in second place in the team competition. In the 1978 championships, the Zlín was more successful, with Czech-flown Z 50’s finishing first and third in the individual competition, and a German-flown Zlín finishing fourth, with the Czechoslovak team winning the team competition. Zlín Z-50s finished fourth in the 1980 championship, and third in the 1982 competition.
The Zlin Z-50LS, with a more powerful 300 HP Lycoming AEIO-540 L1B5D engine, was first flown by Zdenek Polasek on 29 July 1981. The more powerful engine enhanced vertical maneuvers. The Zlin Z-50LS can fly at 760 kg gross weight in the aerobatic category (+8g 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.
Zlín Z-50M affectionately Known as the “Baby Fifty” was later released and as a replacement for the Zlin 26 and was fitted with a Avia M-137AZ engine producing 180 HP The Z-50M has limited manoeuvring 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 manoeuvrability 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.
Variants of the Zlin 50 include:
Z-50L
First production variant with a Lycoming AEIO-540-D4B5 engine, certified in 1977, conversion to 50LA and 50LS variants, 25 built. Serial numbers 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.
General characteristics of the Zlin 50 LS
Crew: 1
Length: 6.62 m (21 ft 8¾ in)
Wingspan: 8.58 m (28 ft 1¾)
Height: 1.86 m (6 ft 1¼ in)
Wing area: 12.5 m² (134.55 ft²)
Airfoil: NACA 0018 at root, NACA 0012 at tip
Aspect ratio: 5.89:1
Empty weight: 570 kg (1,257 lb)
Max. takeoff weight: 720 kg (1,587 lb)
Powerplant: 1 × Lycoming AEIO-540-L1B5D air-cooled flat-six engine, 300 hp
Performance
Never exceed speed: 181.5 knots, 209 mph
Maximum speed: 158 knots, 182 mph at 1,640 ft
Cruise speed: 129 kt, 149 mph economy cruise at 1,640 ft
Stall speed: 53 knots, 61 mph
Range: 640 km (345 nmi, 397 mi) with max fuel, including tip tanks
Service ceiling: 19,675 ft
Rate of climb: 2,360 ft/min
Wing loading: 57.6 kg/m² (11.8 lb/ft²)
Power/mass: 3.71 kg/kW (6.10 lb/hp)
Many of these amazing machines made their way to South Africa over the years and are still used in aerobatic competitions today, Werner Nel took to the air at Kitty Hawk airfield on Sunday 1 October 2017 in his rebuilt Zlin 50 LS under the watchful eye of Chris Joubert, Chris also owns a Zlin 50 LS and they are both expected to take part in the upcoming competition aerobatics season this coming year.
