First reference to this aircraft came in a Novosti Press Agency bulletin on 30 June 1975, which stated that tests of a new Yakovlev sporting aircraft, designated Yak-50, had been carried out near Arsenyev in the Soviet Far East. Mr Nikolai Sazykin, director of the Progress Engineering Works in which all Yakovlev sporting aircraft are assembled, was quoted as saying that the Yak-50 was intended to participate in the 1976 world aerobatic championships. Test pilot Anatoly Sergeyev stated only that it was more advanced than the familiar Yak-18 training and aerobatic monoplane, with a more powerful engine, better manoeuvrability, a speed of over 215 knots (400 km/h; 248 mph) in a dive, and the ability to perform all aerobatics with its landing gear retracted or extended.
When six Yak-50s participated in the 1976 world aerobatic championships at Kiev, their evolution from the Yak-18 was apparent, but with significant changes. Basic configuration is little different from that of the single-seat Yak-18PS, with tailwheel type landing gear. This was deliberate, to keep the handling characteristics of the two types as similar as possible. However, overall dimensions are reduced; control surface hinge lines have been moved to keep control forces light; and overall structural strength has been increased by switching entirely to metal covering. In particular, the fuselage is now semi-monocoque instead of steel tube with fabric covering to the rear of the cockpit. Designers responsible for these and other changes were Sergei Yakovlev (son of Alexander Yakovlev) and Yuri Yankievich.
The wings dispense with the Yak-18’s centre-section, have 2° dihedral and 2° incidence, and retain an asymmetric section. To ensure a high power/weight ratio in a relatively large aerobatic aircraft, the power plant is a 268 kW (360 hp) Vedeneyev (Ivchenko) M-14P aircooled radial piston engine, driving a V-530TA-D35 two-blade variable-pitch propeller, instead of the 224 kW (300 hp) Ivchenko AI-14RF of the Yak-18PS. Mainwheel tyre size is 500 x 150, tailwheel tyre size 200 x 80. The main fuel tank, capacity 55 litres (14.5 US gallons; 12 Imp gallons), is aft of the engine firewall, the electrical system battery behind the pilot’s seat. A Zyablik radio transceiver is standard.
Observers at the 1976 world championships at Kiev reported that the Yak-50s performed the all-important Aresti manoeuvres with precision, their primary shortcoming being excessive directional stability. Yak-50s flown by V. Letsko and I. Egorov finished first and second in the men’s competition. Others came fifth, seventh and ninth, to win the team prize. First five places in the women’s championship were taken by Yak-50s.