Zlin Z-50
Czechoslovak aerobatic aircraft
In May 1971, when we reported on the last acrobatic novelty of the Otrokovica Moravan - the Z-526 AFS aircraft - we expressed the hope that the era of acrobats in Moravan would not end with this type. We were all the more happy when, on July 21st, the chief pilot peeled off the Moravan VI. Berg from the factory airport brand new aerobatic aircraft marked Z 50 L.
The new acrobat is exceptional in every way. It is not at all a continuation of the proven Z-26 series, it is built specifically for acrobatics and what is the main thing and is unprecedented in our country - only 16 months (!) passed from the creation of the first "fly" to the first take-off.
The overall design and processing was undertaken by an initiative construction group headed by engineer J. Mikula, the author of the well-known Z-42 and Z-43. The biggest problem was probably the choice of a suitable power unit, since it was known from the time of the Z-526 that even the existing available engine was already quite weak for peak performance. The considerations of the designers were also influenced by the fact that successes at world competitions, which are closely related to the performance of machines, always influence business success for a time and are considered a measure of the technical maturity of the industry of the respective country. This is also why it was necessary to prove that we are not living off our former glory and that we are able to keep up with the world's best even in this demanding industry.
Although it is very early to judge the performance and flight characteristics of the Z 50 L, it seems so far that the designers had a lucky hand. Of course, the designers' work did not end with the successful flight. Currently, everything possible is tested, verified and improved before a new aircraft can go to its certification, i.e. obtain a certificate of competence according to international building regulations.
When we saw the first picture of the neat newborn, we immediately thought what many of you probably thought: after all, he is a model! That is also why we wanted to print the materials in our column as soon as possible, even if it is only a prototype design. On that occasion, we wish the employees of n. p. Moravan to reach the highest goals with the new Z 50 L.
TECHNICAL DESCRIPTION
The Z 50 L is a single-engine single-seater self-supporting all-metal low-wing aircraft with a fixed two-wheel landing gear.
The half-shell hull is made of duralumin sheet. The transparent one-piece cockpit cover is hinged to the right side. There is cabin ventilation on the front of the cover and a sliding window on the left side. The pilot's seat adapted for a back parachute is adjustable. In addition, it is also possible to change the inclination of the backrest and adjust the foot pedals, so that even a pilot with extreme body proportions can sit comfortably. The dashboard is equipped with all the necessary instruments for checking flight and engine operation. Under the board is a panel with the LUN 3524 radio station and all switches and controls.
The trapezoid-shaped wing without edge arches (just covered with ABS foil over the end profile) is all-metal, single-beam, structurally continuous. It has a NACA 0018 profile at the root, NACA 0012 at the tip. The wing has no flap. The cover is made of aluminum-plated duralumin sheet, and the wing is covered in the same way. The slight lift is only due to the decrease in the thickness of the profile from the root to the end, the upper side of the wing when viewed from the front is straight.
The tail surfaces are structurally unusual. While the keel surface grows organically from the hull, the stabilizer is bisected. Each of its halves is fixed at two points on the cleat and supported by a metal brace riveted from two halves. The tail surfaces, including the keel and stabilizer, are covered with canvas, while the edge arches, like the wing, are shaped from ABS.
Engine group. The flat six-cylinder air-cooled Lycoming AEIO 540 D4 B5 engine with an output of 191 KW (260 hp) at 2700 rpm drives a three-bladed propeller with constant speed of the Hoffmann type НО V123 K/200AH. The removable engine cover made of glass laminates is divided vertically into two parts . The 60 I main fuel tank is molded into the upper contour of the fuselage in front of the pilot so that it forms a direct part of the fuselage system. It is possible to mount additional tanks of 50 I on the ends of the wing.
An oil cooler is included in the oil system. Oil vapors from the engine are removed through a pipe along the landing gear to the level of the wheel, so that the cabin cannot be polluted during flight turns.
Landing gear. The fixed two-wheel chassis consists of a continuous spring made of light alloy, which is fixed to the hull with two yokes. The wheels have mechanical brakes. The spur consists of a spring equipped with a small wheel with automatic locking of positions: fixed (start) and free (non-linear travel).
Coloring. The first prototype, marked with the factory registration mark OK-070, flies in the natural colors of the material. The second prototype, registered OK-072, is painted on a natural red base (see drawing and photo). The registration marks OK-072 on the fuselage and the number 002 on the rudder are black, the upper side of the fuselage in front of the cabin is dull grey-green. On the keel there is Czechoslovak flag. The propeller has white front blades, the propeller cone and blade ends are red.
Technical data and performance: Wing span 8.58 m, total length 6.51 m, height 1.86 m; wing area 12.5 m2. The manufacturer has not given the weights yet. Speeds: maximum permissible 337 km/h, cruising 255 km/h, falling 90 to 100 km/h, maximum climbing speed 15 m/s. Takeoff length over a 15m obstacle 200m, landing length 300m.