|Power at 0m||80hp|
|Weights and loads|
|Wing Load (kg/m2)||46|
|Power load (kg/hp)||87.5|
he Yak-20 was designed to match demands of the aeroclubs in new trainer machine, replacing aging Po-2 biplane. Choice of relatively low output 80hp AI-10 radial engine put strict demands on the airframe weight.
The all-metal construction was relatively light, durable and feasible for mass production (construction of fuselage utilized steel pipes and wing used aluminum alloys). Side by side design of cabin was used in order to spare weight, to save instruments (costs), to simplify systems and to maintain better contact between teacher and student (which should accelerate the training for about 30%). The large canopy provided good view, necessary for training and cross country flying. Fixed taildragger landing gear was chosen to save weight and simplify primary training.
Two-blade adjustable propeller V-515 was installed, total fuel capacity in two wing tanks was 70l.
The maiden flight of Yak-20 occurred in Winter 1950. Good flying and handling qualities were confirmed by contemporary civil and military test pilots (Sergey Anokhin, Georgiy Shijanov). Except minor problem (solved during trials) with canopy sliding mechanism, trials were successful.
It was not put into production. The reason was Cold War and growing need for military training. Yak 18 with its more powerful engine, tandem cockpits and tricycle landing gear was more suitable for this purpose. Also the engine design bureau of A.Ivchenko switched its effort to other (military) programs.
Today all civil aircraft and many combat planes use side-by-side cockpit arrangement. Trainer similar to the Yak-20 could be useful today - of course with application of modern materials and technologies.
|3D drawing used for background on this page, courtesy of Stanislav Cerny|