WSK Nr 4 PZL Okęcie Jak-12. 1952 - Construction

Category: Airplanes Last change: September 2020 History Construction Tally

Kraków 2020-09-01

101b Section 1952

WSK Nr 4 PZL Okęcie Jak-12


Construction Jak-12 (Як-12).

Jak-12 nb SP-ASZ. 2018 year. Photo by Karol Placha Hetman
Jak-12 nb SP-ASZ. 2018 year. Photo by Karol Placha Hetman

Jak-12 nb SP-ASZ. 2018 year. Photo by Karol Placha Hetman
Jak-12 nb SP-ASZ. 2018 year. Photo by Karol Placha Hetman

The Jak-12 is a multi-purpose, single-engine, high-strut wing, metal structure, covered with duralumin sheet, 0.4-1.0 mm thick, and canvas.


Wings with a rectangular contour. In the Yak-12 A version, the outer parts of the wings have a trapezoidal outline. Double-spar wing structure; main girder and rear auxiliary girder, which connects to the main girder near rib no. 19. The wing has 36 ribs. The wings are covered with duralumin and linen. A reflector and a Pitot tube are placed on the left wing. The wing is equipped with ailerons, flaps and slots (gills - fixed in the early versions, automatic in the Yak-12A).


The fuselage of the truss structure, made of 30HGSA steel pipes. They are profiled with duralumin stringers. The front part of the fuselage is covered with D16A-T duralumin sheet. The back is covered with AM-100 natural or synthetic canvas. The fuselage begins with a firewall made of steel sheet. The bed is attached to this partition, and the engine to it. Access to the fuselage is provided by doors on both sides. They have an emergency dump system. The windows are made of organic glass.


Classic tail with the division into rudders and fins. The rudders are equipped with balancing flaps. Rudder controlled 25 degrees to both sides. The elevator tilts 30 degrees up and 20 degrees down.


Fixed landing gear, classic, with a tail wheel. The main chassis is equipped with brakes.


The first versions of the Jak-12 were equipped with the M-11 engine with a capacity of up to 160 HP. The M-11 engines were manufactured and repaired in Poland.

9-cylinder AI-14 R engine with a nominal power of 220 HP (161 kW) and a starting power of 260 HP (191 kW). The engines were produced in Kalisz in PZL-Kalisz under the designation PZL AI-14R. Air cooled. Air flow regulated by a shutter. The engine is covered with a two-piece cover (upper section and lower section).

Adjustable pitch two-blade propeller. Spans up to 2.70 m.

Two fuel tanks in the wings with a total capacity of 225 liters. Two additional tanks with a capacity of 95 liters can be suspended under the wings.

Data T-T Jak-12 M:

Span 12.60 m

Length 9.00 m

Height 3.12 m

The bearing area is 22.60 m

Curb weight 1 026 kg

Gross weight is 1,450 kg

Load weight 300-424 kg

Fuel supply 115-180 liters

Top speed 180 km / h

Cruising speed 160 km / h

Rate of climb 4.1 m / s

Landing speed 82 km / h

The maximum range is 765 km

Range with a load of 450 km

Flight time 3 hours

Service ceiling 4 169 m

Takeoff 126 m

Landing distance 90 m.

Data T-T Jak-12 M:

Span 12.70 m

Length 9.00 m

Height 3.12 m

The bearing area is 23.80 m

Curb weight 1 059 kg

Gross weight is 1,588 kg

Load weight 529 kg

Fuel supply 225 liters

Top speed 210 km / h

Cruising speed 180 km / h

Rate of climb 3.9 m / s

Landing speed 89 km / h

The maximum range is 1,070 km

Range, laden 600 km

Flight time 3.5 hours

The ceiling is 4,000 m

Runway 153 m

Landing distance 131 m.

Written by Karol Placha Hetman