General Information
Type Yak-20
Function trainer
Year 1950
Crew 1+1
Powerplant
Type AI-10
Power at 0m 80hp
Size
Length 7.07m
Wingspan 9.56m
Wing area 15m2
Weights and loads
Empty 470kg
Loaded 700kg (750?)
Wing Load (kg/m2) 46
Power load (kg/hp) 87.5
Speed
Maximum 160km/h
Landing 60km/h
Maneuverability
Turn time ?sec
Roll
Landing m sec
Takeoff m sec
Range
Practical km
Flight Endurance hmin
Ceiling
Ceiling 3000m
Climb
1000m ?min
Payload
Fuel 70l

Yak-20 trainer by A.S.Yakovlev

36k b/w photo, courtesy of Stanislav Cerny

T

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.

48k b/w photo, courtesy of Stanislav Cerny

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
References
  • Thorny way to nowhere
  • Links
  • Early Yakovlev's trainers

  • Created April 9, 2001
    with help of Stanislav Cerny
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