Aviation of Word War II

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UT-2L

UT-2L in flight
  • Training Aircraft
  • Firsr flight: 1944
  • Yakovlev

UT-2L. Considering the importance of training flight personnel, the design team headed by A.S. Yakovlev, and in the most difficult war years he improved our main training aircraft UT-2. In particular, in 1942 the UT-2M was created and put into mass production, and at the end of 1943 a new training aircraft UT-2L was designed. Developing his project, the designers sought to bring the training aircraft as close as possible to the combat aircraft in order to reduce the time for commissioning young pilots. The UT-2L was equipped with brake wheels, a landing shield, a closed cockpit, etc. Tests that began in the summer of 1944 showed that the UT-2L is much simpler than the UT-2 in terms of piloting technique,

The structure of the double UT-2L is wooden. The wing is two-spar with smooth plywood skin. Fuselage - truss, also wooden with plywood fairing. The empennage and aileron frame is duralumin. Linen upholstery. Non-retractable chassis, with oil-gas damping. Brake wheels are covered with fairings. A landing shield was installed under the center section.

The streamlined hood, which covered the cylinder heads, significantly reduced the aircraft's drag and improved the thermal regime of the M-11D engine with a power of 145 hp.

In the same 1944, a single-seat Yak-5 aircraft was created for training fighter pilots. It is similar in geometry and design to the UT-2L, but had retractable landing gear and a variable pitch propeller. More extensive flight and navigation equipment, including a powerful landing headlight, made it possible to conduct training on the Yak-5 in difficult weather conditions and at night. Additional equipment, a radio station, a radio compass and a synchronous ShKAS machine gun of 7.62 mm caliber brought this training aircraft as close as possible to combat.

The Yak-5 and UT-2L were completely unified and had almost the same flight characteristics. This greatly simplified the serial production and operation of both types of aircraft in educational institutions, and made it possible to reduce the time for pilot training. Takeoff weight of the Yak-5 - 940 kg, UT-2L - 950 kg, the maximum speed with the M-11D engine for the Yak-5 reached 250 km / h, for the UT-2L - 225 km / h, landing, respectively, 85 km / h h and 75 km / h, flight range - 450 and 700 km.

Both experimental training aircraft have been successfully tested.

It was assumed that the release of UT-2L will swing as the needs of the front in combat vehicles decrease. However, by 1944, our aviation was already armed with machines with very high speeds, the industry produced mainly aircraft of an all-metal design. Therefore, the release in 1945 of even a training wooden aircraft was considered inappropriate. Neither the Yak-5 nor the UT-2L were mass-produced. On the basis of the UT-2L, immediately after the end of the war, an all-metal Yak-18 was created. In appearance and geometry, the Yak-18 in many ways resembles the UT-2L. On this post-war machine, some elements tested on the UT-2L and Yak-5 were also used, including a power plant with a variable pitch propeller, a landing shield, a retractable landing gear, a cockpit canopy, and others.

It is worth noting that the design bureau team headed by A.S. Yakovlev has an integrated approach to the creation of training aircraft - two at once, as unified as possible - a double and a single. Their consistent use in the training process makes it possible to train qualified pilots faster and at lower cost.

UT-2L Specification
Crew 2
Dimensions
Wing span, m 10.50
Wing area, m² 17.00
Length, m 7.30
Powerplant
1 × PE air-cooled M-11D, hp 1 × 145
Masses and loads, kg:
Normal takeoff 950
Performance
Maximum speed, km/h 225
Cruise speed,km/h 200
Service range, km 700
Photo Description
UT-2L drawing

Drawing UT-2L


Yak-5

Як-5
  • Training Aircraft
  • Firsr flight: 1944
  • Yakovlev

In 1944, a single-seat Yak-5 aircraft was created to train fighter pilots. It is similar in geometry and design to the UT-2L, but had retractable landing gear and a variable pitch propeller. More extensive flight and navigation equipment, including a powerful landing headlight, made it possible to conduct training on the Yak-5 in difficult weather conditions and at night. Additional equipment, a radio station, a radio compass and a synchronous ShKAS machine gun of 7.62 mm caliber brought this training aircraft as close as possible to combat. Yak-5 and UT-2L were completely unified and had almost the same flight characteristics. This greatly simplified the serial production and operation of both types of aircraft in educational institutions, and made it possible to reduce the time for pilot training. Takeoff weight of the Yak-5 - 940 kg, UT-2L - 950 kg, the maximum speed with the M-11D engine for the Yak-5 reached 250 km / h, for the UT-2L - 225 km / h, landing, respectively, 85 km / h h and 75 km / h, flight range - 450 and 700 km. Both experimental training aircraft have been successfully tested.

The Yak-5 was not mass-produced. Taking into account the experience of designing, building and operating the UT-1 and Yak-5, the design team in 1945 developed the Yak-11 training fighter, which, with the ASh-21 engine with a power of 570 hp. developed a speed of up to 465 km / h.

Created during the war years, the experimental UT-2L and Yak-5 were further developed in the post-war years in the two-seat Yak-18A and the single-seat aerobatic Yak-18P; jet double Yak-30 and single Yak-32; piston single aerobatic Yak-50 and double Yak-52.

Yak-5 Specification
Crew 1
Dimensions
Wing span, m 10.50
Wing area, m² 17.00
Length, m 7.30
Powerplant
1 × PE M-11D, power hp 1 × 145
Weight, kg
Empty 770
Loaded weight 940
Performance
Maximum speed, km/h 250
Cruise speed, km/h 220
Service ceiling, km 450

Yak-11

Yak-11 with S-13 photo machine gun
  • Training Aircraft
  • Firsr flight: 1946
  • Yakovlev

Yak-11. The main aircraft for training pilots during the Great Patriotic War were the U-2 (Po-2) and the UTI-4, which were exhausted. Two-seat export fighters Ya-7V, Yak-9V and La-7UTI were a rarity in flight schools - they were not enough even in reserve regiments, and training pilots for them was a little expensive. In this regard, even during the war years, OKB-115, headed by A.S. Yakovlev, began developing the future Yak-18, which replaced the Po-2 as a "school desk" for pilots. However, future air fighters needed an aircraft to train them in shooting at air targets and bombing.

Under the very "curtain" of the Great Patriotic War, on April 29, 1945, factory tests of the latest modification of the Yak-3 fighter with the ASh-82FN star-shaped engine began at the Central Aerodrome of Moscow. During the tests, the pilot P.Ya.Fedrovi reached a speed of 682 km / h at an altitude of 6000 m. The climb time of 5000 m did not exceed 3.9 minutes. However, despite such high performance, the aircraft remained unclaimed.

A year later, on its basis, a training aircraft (UTS) Yak-U (subsequently designated Yak-11) with a single-row star-shaped ASh-21 engine with a take-off power of 700 hp was created. and variable pitch propeller VISH-IIIV-20. The ASh-21 engine with direct fuel injection was, as it were, half of the ASh-82 and had a drive centrifugal supercharger and gearbox. Initially, the motor resource was 100 hours, then it was increased to 150 hours. The first flight and factory tests were carried out by the pilot G.S. Klimushkin under the guidance of the chief engineer V.A. Shavrin in 1946. The pilots M.I. Ivanov and F.L. Abramov also flew around the machine.

In the same year, the Yak-11 passed state tests at the State Research Institute of the Air Force (leading pilot P.M. Stefanovsky) and was put into serial production at the plant No. 292 in Saratov. The Yak-11 glider basically repeated the Yak-3. The exception was the double cabin. Its armament consisted of a 12.7 mm UBS synchronous machine gun with pneumatic reloading and electro-pneumatic trigger and 100 rounds of ammunition, as well as two 50-kg bombs on BD2-45 wing holders, located outside the plane swept by the propeller, at a distance of 2055 mm from the axis aircraft. On the first serial machines, a PBP-1A sight was installed in the cadet's cockpit, and a PAU-22 photo machine gun was installed in the left wing console (a landing light was placed in the right console of the bearing surface). The chassis was preserved from the Yak-3, but the crutch wheel was made non-retractable.

Yak-11 Specification
Crew 2
Dimensions
Wing span, m 9.20
Wingarea, m² 15.40
Lenghth, m 8.50
Height, m 3.28
Powerplant
1 × PE ASh-21, power hp 1 × 570
Masses and loads, kg:
Empty plane 1,854
Maximum takeoff 2,418
Performance
Maximum speed, km/h 456
Cruise speed, km/h 330
Service range, km 1,290
Service ceiling, m 7000
Armament
4 × synchronized 12.7 mm UBS machine gun
2 × (25-100)-kg bombs, PAU-22 camera gun
Photo Description
Yak-11 drawing

Drawing Yak-11

Contrary to the conclusion of the Civil Code of the Air Force Research Institute and the opinion of K.P. Vershinin, serial machines had an insufficient margin of longitudinal stability, and controllability left much to be desired. I had to limit refueling to 150 kg instead of 268 kg. The last defect could be eliminated only by replacing the horizontal tail. "The Yak-11," test pilot A. Muravyov recalled, "was a beautiful aircraft. Blunt-nosed, sturdy and strict. It required extremely strict control." This brief description is confirmed by the statements of many pilots who have been trained on the "yak".

In the spring of 1948, the pilots of the Civil Aviation Research Institute of the Air Force I.M. Dzyuba and V.G. Ivanov conducted state tests of the Yak-11 with the new ASP-1N sight and the S-13 photomachine gun, which were equipped with fighters in those years. Unlike previous photo-machine guns, the S-13 was mounted on the visor of the cockpit canopy.

The need for the Yak-11 was so great that, starting next year, its production was mastered by the Leningrad plant No. 272. In the process of serial production of the Yak-11, changes were constantly made to its design, equipment and weapons. In particular, they replaced the wooden formwork of the fuselage and the canopy of the pilots' cabins with a metal one and changed the location of the individual rods of the machine gun truss. In 1950, pilot G.T. Beregovoy tested the ASP-ZN sight, which later replaced the PBP-1A collimator sight on a machine manufactured in Leningrad, and on which control tests were carried out after that. The aircraft equipment also included the RPKO-10P radio semi-compass and the RSI-6K fighter radio station, which were installed on new combat vehicles, and the SPU-ZM intercom. These and previous improvements were fully implemented on machines, starting with the 24th series in 1951. At the same time, the Yak-11 was equipped with an electric combined artificial horizon AGK-47B with a roll scale instead of the diving artificial horizon AGP-2 and the direction indicator UP with a vacuum pump AK-4S (stopped installing from vehicle No. 01209). On the visor of the cadet's lantern, a C-13 photo machine gun was installed instead of the wing PAU-22. An AFA-IM aerial camera was placed behind the cockpit. From aircraft no. 58201 changed the fuel system, now it allowed to fully develop fuel. The use of airborne navigation lights BANO-45 and new flight and navigation equipment increased flight safety.

Bibliography

  • History of aircraft designs in the USSR, 1938-1950. /V.B. Shavrov/
  • Experienced aircraft of the Second World War /Ivnamin Sultanov./
  • Yak-11: Winged school desk / Modeler-Constructor. M. Orlov, N. Yakubovich./
  • UT-2L, Yak-5 / Wings of the Motherland. V. Petrovich./