"Il-2" redirects here. For other uses, see IL-2
The Ilyushin Il-2 (Cyrillic: Илью́шин Ил-2) Sturmovik was a ground-attack aircraft (Cyrillic: Штурмови́к, Šturmovík) in the Second World War, produced by the Soviet Union in very large numbers. With 36,183 examples of the Il-2 produced during the war, and in combination with its successor, the Ilyushin Il-10, a total of 42,330 were built, making it the single most produced military aircraft design in aviation history, as well as one of the most produced piloted aircraft in history along with the American postwar civilian Cessna 172 and the Soviet Union's own Polikarpov Po-2 Kukuruznik biplane, itself sometimes seen side-by-side with the big armored Ilyushin monoplane on the front lines.
To Il-2 pilots, the aircraft was simply the diminutive "Ilyusha". To the soldiers on the ground, it was the "Hunchback", the "Flying Tank" or the "Flying Infantryman". Its postwar NATO reporting name was "Bark". The Il-2 aircraft played a crucial role on the Eastern Front. Joseph Stalin paid the Il-2 a great tribute in his own inimitable manner: when a particular production factory fell behind on its deliveries, Stalin sent an angrily-worded cable to the factory manager, stating "They are as essential to the Red Army as air and bread." "I demand more machines. This is my final warning!"
Design and development
Il-2M at the National Aviation Museum in Krumovo, Bulgaria
The idea for a Soviet armored ground-attack aircraft dates to the early 1930s, when Dmitry Pavlovich Grigorovich designed TSh-1 and TSh-2 armored biplanes. However, Soviet engines at the time lacked the power needed to provide the heavy aircraft with good performance. Il-2 was designed by Sergey Ilyushin and his team at the Central Design Bureau in 1938. TsKB-55 was a two-seat aircraft with an armoured shell weighing 700 kg (1,540 lb), protecting crew, engine, radiators, and the fuel tank. Standing loaded, the Ilyushin weighed more than 4,700 kg (10,300 lb), making the armoured shell about 15% of the aircraft's gross weight. Uniquely for a World War II attack aircraft, and similarly to the forward fuselage design of the World War I-era Imperial German Junkers J.I armored, all-metal biplane, the Il-2's armor was designed as a load-bearing part of the Ilyushin's monocoque structure, thus saving considerable weight. The prototype TsKB-55, which first flew on 2 October 1939, won the government competition against the Sukhoi Su-6 and received VVS designation BSh-2. The prototypes - TsKB-55 and TskB-57 - were built at Moscow plant #39, at that time the Ilyushin design bureau's base.
The BSh-2 was overweight and underpowered, with the original Mikulin AM-35 1,022 kW (1,370 hp) engine designed to give its greatest power outputs at high altitude. Because of this it was redesigned as the TsKB-57, a lighter single-seat design, with the more powerful 1,254 kW (1,680 hp) Mikulin AM-38 engine, a development of the AM-35 optimised for low level operation. The TsKB-57 first flew on 12 October 1940. The production aircraft passed State Acceptance Trials in March 1941, and was redesignated Il-2 in April. Deliveries to operational units commenced in May 1941.
The 23 mm armament of Il-2 was subject to a competition. One of the first 1940 photographs of the Il-2 show it equipped with two MP-6 guns developed by Yakov Taubin (Яков Таубин) at OKB-16. The MP-6 gun weighed 70 kg and developed an initial muzzle velocity of 900 m/s. It operated on the short recoil principle and had a rate of fire of about 600 rpm. (The development of the MP-6 gun can be traced back to 1937. The initial version was tested in the spring of 1940 on a Bf 110 bought from Germany, because there was no suitable Soviet aircraft on which to mount it. In the summer of 1940 it was tested on the Pashinin I-21.) Factory trials of the MP-6 gun on the Il-2 were conducted in August 1940. In the early Il-2 prototypes, these guns were fed by 81-round clips. In flight, these clips sometimes became dislodged because of their large surface, which caused them to experience significant aerodynamic pressure. Competitive tests were conducted in the spring of 1941 between the MP-6 gun modified to belt-fed and the newly developed, gas-operated Volkov-Yartsev VYa-23, which had otherwise rather similar characteristics. The VYa-23 was declared winner at this trial. Subsequently, in May 1941, development of the MP-6 gun was terminated and Taubin was arrested and summarily executed in October that year.
The Il-2 is a single-engine, propeller-driven, low-wing monoplane of mixed construction with a crew of two (one in early versions), specially designed for assault operations. Its most notable feature was the inclusion of armor in an airframe load-bearing scheme. Armor plates replaced the frame and paneling throughout the nacelle and middle part of the fuselage, and an armored hull made of riveted homogeneous armor steel AB-1 (AB-2) secured the aircraft’s engine, cockpit, water and oil radiators, and fuel tanks.
In early 1941, the Il-2 was ordered into production at four factories, and was eventually produced in vast quantities, becoming the single most widely produced military aircraft in aviation history, but by the time Nazi Germany invaded the Soviet Union on 22 June 1941, only State Aviation Factory 18 at Voronezh and Factory 381 at Leningrad had commenced production, with 249 having been built by the time of the German attack.
Production early in the war was slow because after the German invasion the aircraft factories near Moscow and other major cities in western Russia had to be moved east of the Ural Mountains. Ilyushin and his engineers had time to reconsider production methods, and two months after the move Il-2s were again being produced. The tempo was not to Premier Stalin's liking, however, and he issued the following telegram to Shenkman and Tretyakov:
You have let down our country and our Red Army. You have the nerve not to manufacture IL-2s until now. Our Red Army now needs IL-2 aircraft like the air it breathes, like the bread it eats. Shenkman produces one IL-2 a day and Tretyakov builds one or two MiG-3s
daily. It is a mockery of our country and the Red Army. I ask you not to try the government's patience, and demand that you manufacture more ILs. This is my final warning.
As a result, "the production of Shturmoviks rapidly gained speed. Stalin's notion of the Il-2 being 'like bread' to the Red Army took hold in Ilyushin's aircraft plants and the army soon had their Shturmoviks available in quantity."