75 years ago TsKB-55, prototype IL-2, took offThe problem of aircraft protection from ground fire appeared with the start of applying aviation for military purposes. In the beginning pilots had to put pieces of metal or even iron frying pans under their seats.
Aircraft designers of Great Britain, Germany and Russia tried to solve the problem of aircraft protection many times. Junkers and Sopwith even built aircraft armoured with flat sheets. But it appeared to be not so easy. After attaching armour the aircraft turned into a heavy slow machine. For a long time nobody couldn’t manage to combine demands of ground forces support and fire liveness in one aircraft. Aircraft designers even suggested for some time that it is impossible to engineer an armoured attack plane.
However such aircraft was designed. It is interesting, that it appeared not due to the order of authorities, but at the initiative of the outstanding aircraft designer Sergey Vladimirovich Ilyushin.
“It took some time to start engineering the attack plane, I was preparing for that for near three years. I properly analyzed the existing machines and came to a conclusion that the main thing is to combine weight, armour, weapon and speed”, - Ilyushin recalled later.
In January 1938 he applies to the government with a proposal to build a two-seat armoured attack plane, which he designed. In his letter to Stalin, Voroshilov and Molotov he wrote “The task of building armoured attack plane is difficult and risky in terms of technique, but I undertake it with enthusiasm and confidence”.
Since October 1937 Ilyushin combined two positions of high responsibility: General designer of Design Bureau plant No 39 and Chief of main directorate of testing aircraft building in people’s commissariat of defense industry of the USSR. Wishing to focus on design activity he asks the Government to free him from high state position, promising to build an attack aircraft of a new time – “flying tank” - in the shortest time.
He received this resolution and 2 October 1939 test armoured attack aircraft TsKB-55, prototype IL-2, made its first flight. “Ilyushin flew from Chief Directorate onboard IL-2” – there was a joke later.
While engineering the aircraft Ilyushin had to solve a lot of the most difficult technologic and design problems. The main novelty was undoubtedly streamlined armoured frame with the armour as a part of airframe, not attached. Before the armour was additional weight to the aircraft, but now it had functions of structure.
It became possible due to new armoured steel AB-1, engineered by All-Russian Research Institute of Aviation Materials under direction of S.T. Kishkin and N.M.Sklyarov. The armour had good impact toughness and what is the most important – armoured details could be produced by way of hot stamping. Armoured details were stamped in the air, after it they were cooled in oil and from tempering bath it was put back to stamping for final finishing size.
As Ilyushin told, there was endless rattle of shotgun firing to the armoured frame. In such a manner they defined the optimum thickness of the armour for different spots of the cabin, which was from 4 to 12mm.
Not everybody could understand what Ilyushin offered.
“When solders saw the thickness of the armour, they assured that it would be easily broken. But they were mistaken, because when bullet brakes armour with an angle 90 degrees, it is not the same when aircraft flies at high speed, and again, the cabin has a stream-line form. You can try to let off a bullet perpendicularly to the armour surface,’ – Sergey Vladimirovich proved.
The armoured frame protected almost all vital parts of the attack plane: engine, crew seats, fuel and oil systems. For the first time in the USSR transparent armour of K-4 type was applied. Wind screens of cockpit light were made of it.
The war was approaching, but IL-2 was still staying at the plant airdrome, there were endless controversies. Personal address to Stalin was needed, who having estimated the plane decided to put it into mass production.
Remarkable fact is that initially TsKB-55 No1 was double-seat. Together with pilot there was a gunner, who protects the rear semisphere of the aircraft. But the military demanded to increase flight range, speed and altitude ceiling. It could be achieved only by the aircraft weight reduction by gunner cabin and setting additional fuel tanks. The plane was instantly rearranged and it was put into serial production with one seat. It was considered that it would attack under cover of fighter aircraft. But in the beginning of the Great Patriotic War there was shortage of fighter aircraft and attack planes had to act self-sufficiently.
In February 1942 Stalin called Ilyushin and said: “Well, you were right. You’ve made a two-seat attack plane IL-2, and we, without researching it properly, on insistence of some advisors told you to rebuild it into single-seat. Single-seat attack planes suffer heavily from rear attacks. It is necessary to return two-seat machine! Do what you want, but the conveyor must not stop!”
So the attack plane became two-seat again and got its legendary appearance, which can be seen now at many pictures.
A pilot who masters the attack plane well could act as a fighter. One of the most frequently used actions is to reduce speed roughly and shoot a German plane, which went forward, from course guns. If the shooting was successful, the German plane simply broke into pieces. A different matter is that the aircraft was put to combatant forces in March 1941 and pilots were short of time to master it completely. 249 attack planes were produced by 22 June 1941. So pilots had to master IL-2 during the war.
In March 1941 Ilyushin received Stalin’s Prize of the second class for engineering the aircraft. And in five months, in August, he received one more, at this time first class, for perfect fighting characteristics of the aircraft. This is perhaps the only case when a person gets two Stalin’s Prizes for one work.
Modernization of the plant was carried out during the whole war. And in 1944 a new IL-10 attack plane flew to the sky, which had higher speed, armament power and protection.
Some more facts.
IL-2 became the most mass combat aircraft for the country’s history. Total 36 154 attack planes and modifications were produced by serial plants Stalin’s telegram, sent in 1942 to the plant directors Sheikman and Tretyakov in reply to slowdown of the planes production, says: “… IL-2 aircraft are needed by our Red Army as air, as bread… I ask you not to put the Government out of patience and demand more ILs to be produced. This is my last notification. Stalin”.
IL-2 got the name “humpbacked” in the Red Army. It should be not only due to its profile, but because it achieved results as a worker. “Humpbacked” – because it won the war on its shoulders” – pilots said.
The aircraft’s designer S.V. Ilyushin called it “flying tank”.
German pilots called it “concrete tank” for its vitality. Ground forces of Wehrmacht called it “butcher”, “mincing machine”, “iron Gustav”.
There is also a reference that in some German military units it was called “plague” or literally “Black Death”.