Po-2LNB Light Aircraft,Technical Specifications (The USSR)

Po-2LNB Light Aircraft
  • Crew – 2 people
  • Engine – M-11D
  • Power – 115 hp
  • Wingspan-11.4 m
  • Wing area – 35.15 sq. m
  • Empty aircraft weight-773 kg
  • Maximum take-off weight-1400 kg
  • Full load weight-627 kg
  • Maximum speed at altitude / near the ground-138 / 152 km / h
  • Practical ceiling – 4350 m
  • Maximum range-530 km
  • Armament: 1 x 7.62 mm SHKAS machine gun
  • Maximum bomb load-240 kg and 4 NURS M-82.

Po-2LNB Light Aircraft Details

In the 1920s, due to the development of aviation in the Soviet Union, the need for creating a training aircraft of initial training, easy to fly and cheap to produce, increased many times. This served the interests of mass training of pilots in the shortest possible time. In the flight-technical requirements for the future training aircraft, developed by the Scientific and Technical Committee of the Air Force Directorate (UVVS), it was indicated that the speed of such a training aircraft should not exceed 120 km/h. In addition, to ensure the simplicity and cheapness of the design, it was decided to give the aircraft an extremely simple rectilinear “chopped” shape without any curved edges: the wings and tail with a constant profile and chord, the upper and lower wings, right and left, were to be interchangeable, and the elevators and rudders and both ailerons were the same and also interchangeable.

In July 1926, the aircraft designer N. N. Polikarpov received an official assignment to design a training aircraft (intended for the initial training of pilots in aviation schools) for a very successful domestic M-11 aircraft engine with a capacity of 100 hp. Already in early 1927, N. N. Polikarpov presented the project of such an aircraft to the training department of the UVVS. The first version of the U-2 training aircraft (training second) with the M-11 engine was a single-column two-seat biplane of mixed design with an open cockpit and a non-retractable landing gear. The aircraft was mainly a wooden structure made of pine and plywood, with a canvas covering.

On June 24, 1927, the first flight of the U-2 took place, which was piloted by test pilot M. M. Gromov. It was distinguished by its reliability and ease of operation in flight. In general, the aircraft received a good rating, but it was overloaded and had a low rate of climb: it gained 2000 m in 29 minutes. On the second car, we managed to eliminate the identified shortcomings, while: the wing profile became thinner, the ends of the wings and tail were made elliptical, and the rudder was very large. On January 7, 1928, the upgraded U-2 made its first flight, while showing excellent static longitudinal stability. With a large angle of attack and loss of speed, the aircraft lowered its nose and picked up speed again, at full throttle it went up, at low engine speeds it lowered its nose and went down. The plane did not go into a tailspin, but, being introduced intentionally (and with great effort), it quickly came out of it when the control stick was in neutral, even allowing the handle to be thrown for a short time. This was so contrary to the established practice of flying other aircraft of the time, strict in piloting, that the new aircraft was immediately granted general recognition.

The U-2 aircraft was used in Soviet aviation for 35 years, having no equal in this respect not only in the Soviet Union, but also abroad. The durability of the U-2 aircraft testified to the perfection of its design, versatility and successful compliance with newly emerging requirements. Already at the end of 1928, after the test of the experimental U-2 series was completed, its large-scale production was mastered at plant No. 23 in Leningrad. By 1939, the design capacity of plant No. 23 was to produce 2,000 U-2 aircraft per year. At the same time, both the aircraft itself and its power plant were constantly being improved during production, and numerous changes were made to their design. So, since the second half of the 1930s, the U-2 aircraft began to install a more powerful M-11D engine of 115 hp.

For many years, the U-2 aircraft was the main training aircraft of all Osoaviakhim flying clubs and flight schools of the Air Force and Civil Air Fleet. Almost 100,000 pilots were trained on this aircraft during the Great Patriotic War. Despite the fact that the U-2 was originally created as a school aircraft of initial training, the simplicity of its maintenance, as well as the possibility of operating in non-aerodrome conditions, provided it with wide application in a wide variety of variants: agricultural U-2AP “Aeropyl” (for pollination); sanitary-in modifications C-1, C-2, C-3 (SKF), U-2C; three-seat transport, up to the famous night bomber. Such goals were not set in advance when creating it, but the scheme and design of the aircraft were up to par, and life proved what reserves and opportunities were hidden in it.

The arrival of U-2 aircraft in the Red Army Air Force began in 1930. They received their first baptism of fire in the area of Lake Khasan in 1938. There, several sanitary versions of this C-1 aircraft were used to evacuate the wounded. By June 22, 1941, there were 3,500 U-2s in the Soviet Air Force. With the beginning of the Great Patriotic War, the U-2 became truly legendary. This aircraft has received a new, seemingly unexpected application, unprecedented for a light training aircraft of initial training. Already in the autumn of 1941, N. N. Polikarpov, G. I. Bakshaev and other aircraft designers converted it into a light night bomber (LNB). The bomb load of this aircraft reached 350 kg, which became possible due to the exceptional qualities of the U-2 to take a large load without a special elongation of the run-up and without the risk of breakage in the air. At the same time, the aircraft could perform all sorts of aerobatics. As for take-off, the U-2 biplane box with a very low specific load (about 27 kg / sq. m.m) allowed a significant increase in take-off weight (up to 1400 kg) within the capabilities of a 100-horsepower engine. Under its fuselage and lower wing, appropriate holders with cable drop control were installed, and sometimes cassettes for small aerial bombs were placed in the fuselage and under the wing.

In the back seat, 7.62 mm SHKAS or DA machine guns were mounted on a pivot mount, and the pilot received a bomber sight. 50 and 100 kg aerial bombs, M-82 rockets, pipes and bags of flammable liquid, etc. could be suspended from the aircraft. Since 1942, U-2 aircraft of the Armed Forces (military aircraft) began to be delivered from factories ready-made. The main purpose of the new light night bomber was to carry out extremely low-altitude bombing attacks on the front edge and near rear of the enemy, conducted mainly at night – in order to haunt the enemy; deprive him of sleep and rest; exhaust him; destroy its aircraft at airfields, fuel, ammunition and food depots; interfere with the actions of transport, headquarters, operational points, etc. In the role of a light night bomber, these aircraft played a significant role in the Battle of Moscow. During this most difficult period of the Great Patriotic War, from October to December 1941, the Soviet Air Force was formed on outdated biplane aircraft-71 aviation regiment on the U-2 (LNB), 27 air regiments on the R-5 and 5 air regiments on the R-Z. These units took an active part in all subsequent battles of the war. 588th Night Bomber Air Regiment (later 46th Guards Taman Women’s Night Bomber Air Regimentschikov), who flew on the U-2, was equipped with female crews-pupils of aero clubs. During the war years, the 23rd female pilots of the regiment were awarded the title Hero of the Soviet Union. The Germans called the brave pilots of this regiment “night witches”. In 1942-1945, the 46th Guards Night Bomber Aviation RegimentShchikov flew almost 24,000 combat missions.

The range of use of the U-2 aircraft of the Armed Forces at the front was very wide – they were used throughout the war for reconnaissance, communication between military units. These planes also had to fly behind the front line-to the partisans, delivering them weapons, ammunition, food and medicine. Polikarpov’s U-2BC aircraft became a true favorite of Soviet soldiers, who called it affectionately ” cornhusker “(because of its low-level flight), and the German Luftwaffe command, which nicknamed this aircraft” Russ-faner”, even issued an order that ordered pilots to present awards for each downed Po-2 aircraft. U-2BC made its worthy contribution to the Victory in the Great Patriotic War. The U-2 aircraft was renamed Po-2 in 1944, after the death of the aircraft designer N. N. Polikarpov.

During the Great Patriotic War, along with the main version of the U-2BC, several other modifications were produced, including, in 1943, the production of the U-2NAK was mastered – a night artillery spotter, which differed from the U-2BC in the absence of bomb weapons and the installation of artillery correction devices. As a defensive weapon, it had only one 7.62 mm SHKAS machine gun. An exhaust manifold with a silencer was mounted on the engine, which provided a relatively silent flight at a distance of 200-300 m, and a generator driven by the M-11 engine shaft, a radio station and a night sight were also installed.

The U-2NAK was widely used on the Soviet-German front. In 1944, N. N. Polikarpov developed a special version of his aircraft for the special propaganda U-2GN (“Voice of the Sky”), equipped with a powerful radio installation with a loudspeaker, generator and muffler on the exhaust manifold, which was also successfully used at the front.

In total, from 1928 to 1953, more than 33,000 U-2 (PO-2) aircraft were produced at several aircraft factories in 14 modifications, which made it one of the most popular aircraft in the world, and only at plant No. 23 in 1929 – 1940, 10972 U-2 aircraft were manufactured. Between June 22, 1941, and May 1, 1945, the Soviet Air Force received 11,918 U-2 (PO-2) biplanes from OPEC. Moreover, even after the cessation of its production by aircraft factories, this aircraft continued to be built in workshops and repair bases of Aeroflot, until 1959.

The Central Museum of the Great Patriotic War exhibits a mock-up of the U-2 LNB light bomber aircraft (tail number 14), which was part of the 46th Guards Taman Night Bomber Regiment. The model of the aircraft was made by Avion LLP in August 2001. The fabric covering of the aerodynamic surfaces is made according to the technology adopted for the U-2 aircraft. The rudder and aileron control system is operational. The air screw is driven by an electric motor. The model contains fragments of the original U-2 aircraft: crankcase; cylinders; crankshaft; propeller; landing gear wheels; cabin instrumentation.

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