Kraków 2020-09-01
101b Section 1952
WSK Nr 4 PZL Okęcie Jak-12
Poland
History the business plane Jak-12 (Як-12).
Description to the photo: Jak-12 plane No. 169653 with SP-KRC registration, with the AI-14 R engine, 260 HP (191 kW). The plane is owned by the Rzeszów Aeroclub.
Description to the photo: Jak-12 aircraft No. 5013 with SP-ASZ registration, with the M-11 engine up to 160 KM. The plane is an exhibit of the Polish Aviation Museum in Czyżyny in Krakow.
Jak-12 for Poland. 1952 year.
In 1952, a few Yak-12 R planes were brought to Poland. Probably four or five. We know the following machines No. 0225, 5013, 4640213 and 4640216. In fact, these were Yak-12 machines with M-11 FR engines, built between 1950 and 1951. Attempts were made to enter them into the state of the Polish Army. The tests carried out proved their total uselessness (long run-up, low lifting capacity, short range – a definite lack of power of the drive unit). Nevertheless, before the end of the tests, Lieutenant General Ivan Turkiel (Russian in the Polish Army), the then Commander of the Air Force, ordered the planes to be entered in the state.
On September 13-30, 1959 (i.e. a few years later), one of these aircraft was shown at the Wrocław Exhibition at Pilcze Airport.
At the end of January 1952, one of the planes, Jak-12-M-11 FR No. 5013, was transferred to the Aeroclub of the Aviation League. It was registered on February 16, 1952, with marks SP-ASZ. Checkers are painted over the airframe. The machine was painted green as standard, and the underside was blue. Later, the colors were standardized at the Aero Club of the Polish People’s Republic; red-cream. On September 14, 1971, the plane was removed from the register and handed over to the Museum of Aviation and Astronautics in Krakow.
At the Aero Club, attempts were made to use the Jak-12-M-11 FR to tow gliders. But the low engine power and the improper structure of the tail section made it impossible to mount the hook for the tow rope.
At the beginning of the 1960s, the remaining military copies of the Jak-12-M-11 FR were handed over to the Aeroclub of the Polish People’s Republic. They received registrations; SP-CFO, SP-CFP. They served until (respectively) 1968 and 1971.
In 1956, the Polish Army received 5 Jak-12 R machines. Again, they were not new machines. An interesting fact in these machines was the installation of a metal claw, which was extended from the tail part. This claw was to be an additional brake when landing in unprepared terrain. It is not known whether it was a patent developed by designers or a home-grown invention of pilots and mechanics from a Soviet unit.
The first public show of the Jak-12 R nb 01 aircraft took place at the Okęcie Airport on August 26, 1956 – September 9, 1956, at the 1st Warsaw Aviation Exhibition.
Jak-12 production in Poland. 1956.
The Jak-12 M version was the first mass-produced variant. The CCCP industry has not been able to meet the needs. The industry was focused on the production of combat aircraft. The CCCP website offered Poland a license production of this aircraft.
Here are a few sentences of explanation. In 1954, the PZL Okęcie plant produced several hundred Junak-3 and CCS-13 aircraft of different versions. In 1955, the production rate slowed significantly. Only 147 machines. The outlook for 1956 was even worse. The Polish market has already saturated. Theoretically, you could look for buyers abroad. However, without the approval of the CCCP, these were vain intentions.
There was also another point. During the Polish People’s Republic, the construction of the Jak-12 M was presented as much more modern than the ones developed in the first years of the People’s Republic of Poland. In fact, that was not the case at all. Yes, wood and plywood were no longer used in the construction. However, the structure of the fuselage did not differ much from the planes developed by Tadeusz Sołtyk’s team. Besides, it should be remembered that both occupiers of Poland completely destroyed Poland’s pre-war aviation construction potential, which was among the world’s best. All documentation and unique instrumentation were destroyed. Never again has the Polish aviation industry developed to the world level. In the 21st century, freemasons and liberals put the last cross on the Polish Aviation Industry, selling all factories for a song.
In 1955, a decision was made to obtain a license for the production of the Jak-12 M. However, the documentation had to be developed by yourself in the WSK-4 PZL-Okęcie. That was the name of the plant then. The production line had to be significantly rebuilt. This was due to the fact that Polish post-war structures had a mixed structure (metal truss, other wooden elements and covering).
Mieczysław Miłosz fled the first Polish Jak-12. The first production series consisted of 20 aircraft and was completely completed in 1956. In Poland, the Jak-12 M – 1,053 (1,054) units and the Jak-12 A – 137 units were built. Production of the Jak-12 A at WSK PZL Okęcie lasted from 1959 to 1960. In 1960, the licensed production of the Jak-12 aircraft was completed in Poland.
PZL Kalisz started the production of IA-14 R engines. The letter R means the use of a reducer. The use of a reducer allows the use of a larger diameter propeller. Even 2.70 m. Such a propeller gives high static thrust and higher efficiency at low speeds. This improves the take-off characteristics and enables trouble-free towing of the sailplane. However, there are also cons. The larger diameter propeller reduces the top speed from approximately 210-220 km / h to 180-190 km / h.
A significant part of the machines built in Poland went to the Polish Army. The users were DWL (command of air forces), KBW (public security corps), WOP (border protection forces), MW (navy). Many machines went to aviation regiments and were used in liaison squadrons. The army operated 51 machines, including 27 double-deckers, which had the designation UJak-12 M. The last Jak-12 M was removed from the state in 1983. The military also took over 32 Jak-12 A machines.
The Jak-12 M plane with checkerboards was shown for the first time at the 2nd Warsaw Aviation Exhibition in front of the Arsenal on September 7-15, 1957, and at the 3rd Warsaw Aviation Exhibition at Victory Square on August 30, 1958 – September 15, 1958.
The Polish Army provided its Jak-12 M / A planes mainly to flying clubs, institutes and business entities.
Apart from the Polish Army, the Jak-12 M / A planes produced in Poland went to; aeroclub aviation, sanitary aviation, selected business entities. Obviously, the largest number of aircraft was exported to the CCCP.
Written by Karol Placha Hetman
Kraków 2020-09-01
101b Section 1952
WSK Nr 4 PZL Okęcie Jak-12
Poland
Construction Jak-12 (Як-12).
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.
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).
Fuselage.
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.
Tail.
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.
Chassis.
Fixed landing gear, classic, with a tail wheel. The main chassis is equipped with brakes.
Engine.
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
Kraków 2020-09-01
101b Section 1952
WSK Nr 4 PZL Okęcie Jak-12
Poland
Tally.
Jak-12 planes with M-11 FR engines. 1952. Probably four copies of No. 0225, 5013, 4640213 and 4640216, built 1950-1951.
Airplane No. 5013 on February 16, 1952, with registration from SP-ASZ, was transferred to the Aeroclub of the Aviation League. On September 14, 1971, it was removed from the register and transferred to the Museum of Aviation and Astronautics in Krakow.
At the beginning of the 1960s, the remaining military copies of the Jak-12-M-11 FR were put at the disposal of the Aero Club of the Polish People’s Republic. They received registrations; SP-CFO, SP-CFP.
Jak-12 planes R. 1956. 5 machines for the Polish Army were brought to Poland. They were not new machines. The first public show of the Jak-12 R nb 01 aircraft took place at the Okęcie Airport on August 26, 1956 – September 9, 1956, at the 1st Warsaw Aviation Exhibition.
Jak-12 planes M. 1956. Serial production in Poland at WSK-4 PZL-Okęcie. The first production series of 20 units. Mieczysław Miłosz fled the first Polish Jak-12 M.
Jak-12 M airplanes. 1956-1959. 1,054 machines were built in Poland.
Jak-12 A. 1959-1960. 137 machines were built in Poland.
Jak-12 M planes in the Polish Army. In total, 51 machines were used; 27 two-rudders (UJak-12 M), 24 single-rudders.
Jak-12 A planes in the Polish Army. In total, 32 machines were used.
Written by Karol Placha Hetman