As the T-34 Medium Tank was to the success of the Soviet ground effort in World War 2 (1939-1945) so too was the Ilyushin IL-2 "Shturmovik" ground-attack aircraft. The single-engine, twin-seat IL-2 was so critical during the period that it reached production totals in excess of 36,000 units over the span of 1941 to 1945. The type was further adopted by Soviet-aligned nations in the post-war world that included Bulgaria, Czechoslovakia, Hungary, Mongolia, Poland, and Yugoslavia. its successor became the similar Ilyushin IL-10 "Beast" (detailed elsewhere on this site) and this aircraft went on to see a peace-time production total of 6,166.
The IL-2 remains the most-produced combat aircraft in history (2018). During its time in the air, the IL-2 was known by various names including the famous "Shturmovik". "Flying Tank" and "Hunchback" became popular with Soviet Army personnel and NATO assigned it the codename of "Bark". The Germans came to know the machine as "Black Death" for obvious reasons - such was its effect on German Army morale.
Background and Development
As early as the 1930s, the modernizing Soviet military was experimenting with the idea of a dedicated ground-attacker complete with armor protection directly for the pilot and critical operating systems (such as engine and fuel stores). Performance was always lacking in these early attempts which shelved many of the initiatives but fortunes changed when Sergey Ilyushin designed the single-engine, twin-seat "TsKB-55" in 1938 that involved an armored "tub" supporting its crew (weighing some 1,500lb overall). To support the stresses of flight, the wing mainplanes were critical support / load-bearing members of the airframe as a whole.
The basic idea was to field a "flying tank" or sorts, a precise (and useful) combination of armor protection, performance, and firepower to neutralize armored and unarmored ground targets - all the while operating under intense enemy ground-based fire and the threat of direct-interception by enemy fighter aircraft.
It was this unique flying form (becoming the "BSh-2") with its Mikulin AM-35 engine of 1,370 horsepower that was successfully tested and ultimately satisfied Soviet authorities in 1939 (beating out the competing single-seat, single-engine "Su-6" offered by Sukhoi). A first-flight was recorded on October 2nd of that year and a second flyable prototype followed as "TsKB-57" with a Mikulin AM-38 engine of 1,680 horsepower. The engine switch was required for the AM-35 was found to make the original model quite underpowered at low altitudes - defeating the purpose of the attack aircraft.
The TsKB-57 was flown for the first time on October 12th, 1940. Following testing, trials, and formal evaluations, the aircraft was ultimately certified for service and serial production (as the "IL-2") in March of 1941. The first examples were delivered to Soviet Air Force units as soon as May 1941. The German invasion of the Soviet Union then followed in June through Operation Barbarossa - turning the course of the war for all.
The resulting design showcased a combat aircraft of wholly unique appearance for the period. Despite its heavy-class role, only a single - yet-powerful - inline engine was used and this was fitted in the nose in the usual way to drive a three-bladed propeller unit in "puller" fashion. The engine compartment resulted in a noticeably long nose section being used, forcing the cockpit to reside closer to midships. The cockpit seated one or two depending on production model (the original approach seated one crewman). In the lengthened, two-seat cockpit arrangement, the crewmembers were seated back-to-back so the rear gunner could engage targets to the rear of the aircraft with his machine gun with some ease. The fuselage was aerodynamically refined and tapered at the tail to which a single-finned vertical unit was affixed along with low-set horizontal planes (all of these planes featured rounded tips).
The wing mainplanes were positioned well-forward of midships and low-mounted on the fuselage sides to provide the necessary balance and control though its large surface area reduced vision out-of-the-cockpit (as did the long nose). A typical "tail-dragger" undercarriage was used for ground-running which involved two single-wheeled main legs (retractable) and a small, swiveling tail wheel under the vertical tail fin. The canopy was relatively heavily glazed with entry-exit made through sliding and hinged panel sections. For some machine gunners, the canopy was removed in-the-field altogether to promote broader firing angles.
The cockpit featured the usual instrumentation at the forward panel: airspeed, altimeter, and system dials were all present. Pertinent system gauges were to the lower left of center with critical performance dials seated directly ahead. To the lower-right were various indicators including the undercarriage and bomb-release lights. The throttle lever was positioned along a left-hand console and the flight stick was found in its traditional place between the knees at center.
The IL-2 was reaching frontline Soviet Air Force squadrons at the time of the German invasion in June 22nd, 1941 though, in its early-going, the aircraft was found to lack the needed "punch" against advancing German armor and ultimately proved fodder for German fighters when left unprotected in contested skies. This forced Ilyushin to heavily revise the design with improved armor protection and the addition of the second crewman to manage the defensive-minded, trainable machine gun facing the rear.
In addition to this, the original 1,680 horsepower AM-38 inline engine was succeeded by the AM-38F offering 1,750 horsepower output. The original 2 x 20mm ShVAK wing-mounted autocannons were given up in favor of 2 x 23mm VYa autocannons and bomb-dropping and rocket-launching capabilities were both retained but broadened in future applications.
These changes gave rise to the definitive "IL-2M3" which began appearing in useful numbers as soon as August 1942.
In practice, the aircraft (piloted by both men and women in Soviet service) were heavily used in the low-flying and very-low-flying role to enact ferocious attacks on undefended (soft), as well as fortified (hard), enemy targets and positions. Rockets provided a devastating explosive and psychological effect while bombs penetrated all sorts of protected cover and armor. Flights would sometimes fly no higher than tree-top level, giving little to no response time for enemy Anti-Aircraft (AA) crews, and line up to attack the rear flanks of advancing armored formations (typically less defended and weaker as a whole). Over 10,000 IL-2s were thought to be in active circulation at peak usage, the period running from late-1943 into late-1944.
The IL-2 proved itself ten-fold during its years-long commitment to the fight and hugely instrumental in the final two years of the conflict. The airframe had an uncanny ability to withstand excessive amounts of punishment before giving out and many returned to home bases with whole chunks of airframe removed or riddled with FlaK / machine gun fire but the aircraft still deemed flyable. Many of their pilots were awarded the highest Soviet aviation honors and many more of these men and women reflected fondly of their time in the cockpits of their excellent IL-2s.
All this to say that the IL-2 was instrumental in helping to turn the tide of the War in the East - the German advance ultimately stalled and was then forced into retreat all the way back to Berlin by the time the war in Europe ended in May of 1945. IL-2s were active in the air over the famous battles of Stalingrad (August 1942 - February 1943) and Kursk (July 1943 - August 1943) to name a few of their aerial commitments.
Despite its impressive production total (36,000+ examples), the IL-2 was branched out into only a handful of variant forms. This included the original single-seat and twin-seat prototypes as well as the original IL-2 (TsKB-57P) single-seat and IL-2 twin-seat combat-ready production models. The IL-2M, or Model 1943, used the upgraded AM-38F inline engine and switched to the 23mm VYa autocannons for greater forward-facing firepower. The IL-2 Type 3M brought about use of Nudelman-Suranov NS-37 autocannons in streamlined gunpods under the wings (leading to a deletion of the wing-mounted 20mm/23mm cannon sets). Production of this "tank-killing" mark reached 3,500 units.
The IL-2M3 (or "Type 3M" or "Model of 1944") was given broader use of duralumin in its construction allowing for all-metal wings to be used in the series. The mainplane's planform was also revised to include a sweepback of the outer wing section while retaining a straight trailing edge appearance. A training model emerged as the twin-seat IL-2U (also known as the "UII-2") and the IL-2T was drawn up as a proposed maritime torpedo bomber. The latter lost its wing-mounted cannon armament in favor of carrying a single 450mm aerial torpedo but it appears this project went nowhere. Another prototype was the IL-2I intended as something of a "bomber destroyer" - fully armored and heavily armed but crippled by the added weight - it did not progress.
The IL-2 (M-82) was intended as an emergency war measure should production lines of the Am-35 and AM-38 aero engines be disrupted in the German march to Moscow. The M-82 was an inline fighter engine intended to take the place of the original Mikulin installations but testing revealed the mating to be poor in performance and control at the required low altitude flight envelopes.
The IL-10 (NATO codename of "Beast") was a further late-war/post-war evolution of the IL-2 which made it to operational service in 1944 (and was license-built by Czechoslovakia as the Avia "B-33"). The type, detailed elsewhere on this site, became the ground-attack standard of the Soviet Air Force going forward and was fielded by the North Koreans in the upcoming Korean War of 1950-1953.
The IL-16 appeared in up to three prototype forms to cover a modern ground-attack requirement in the post-World War 2 period. It was a further development of the in-service IL-10 but not furthered.
The related IL-1 (detailed elsewhere on this site) was developed as a close-support platform against the competing Sukhoi Su-7. Powered by a Mikulin AM-42 12-cylinder engine of 1,973 horsepower and showcasing a single-seat cockpit and an appearance akin to the IL-2 line, the aircraft was first-flown on June 19th, 1944 (despite its IL-1 designation it appeared after the IL-2). However, the Soviet progress in the war negated the type's usefulness and further development was ultimately abandoned - leaving just a sole, flyable IL-1 prototype to show for the investment.
The IL-2 continued in service into the Cold War period (1947-1991) where it was delivered to Soviet allies across Europe. Bulgaria took on a fleet of 120 IL-2 attackers and 10 IL-2U trainers in 1934 and operated these well into 1954. Similarly, the IL-2 formed a portion of the Hungarian Air Force and these were flown into 1952. Czechoslovakia took on 33 IL-2 attackers and 2 trainer forms for their part and operated them during the war in 1944 into 1949. Mongolian Army Aviation fielded 71 IL-2 aircraft from 1945 onwards and actively supported them into 1954. Yugoslavia fielded the IL-2 in no fewer than ten Air Force squadrons - the last ones were retired in 1954.
The legacy of the IL-2 lives on today in the Sukhoi Su-25 "Frogfoot", the Soviet answer to the American Fairchild Republic A-10 "Thunderbolt II" (Warthog). Like the IL-2, the Su-25 bristles with a broad armament array (missiles, rockets, gunpods and the like), is developed for low-altitude fighting, and has survivability features such as an ejection seat, twin-engine configuration, and armored systems and sub-systems not to mention active and passive warning and countermeasures systems.
The IL-2 can still be found flying in various Russian air show presentations, particularly those centered on the "Patriotic War" as related to World War 2. The aircraft has also been the subject of several long-running, and well-received, flight simulators for armchair pilots.