The Sukhoi Su-2 was the first aircraft design of Pavel Sukhoi and became a two-seat light bomber fielded by the Soviet Air Force in World War 2. Though a relatively modern design at the time of its inception, the Su-2 was quickly overcome by the changing face of war, limiting its reach in both combat and production - some 910 examples were produced in whole but losses for the type were costly. The arrival of the stellar Ilyushin IL-2 saw little use for the Su-2 in the coming war years. As such, the type ceased production sometime in 1942.
The Sukhoi Su-2 had its origins in a 1936 directive under Soviet leader Josef Stalin. The requirement called for a multi-role combat platform that could be called upon to assist advancing troops through high-speed, low-level attacks against enemy formations and emplacements as well as undertake general wartime reconnaissance and assessment of targets. The project was codenamed "Ivanov".
Pavel Sukhoi was an employee of the Tupolev design bureau at the time, learning the ropes as a "student" under Andrei Tupolev himself. The firm put forth the ANT-51 design, a single-engine, two-seat fighter fitting the Shvetsov M-62 series air-cooled radial piston engine. First flight of the aircraft took place on August 25th, 1937 and proved performance to be inferior to what was desired. As a result, the aircraft was re-engined with a more powerful and efficient (yet somewhat unreliable) Tumansky M-87 series engine of 1,000 horsepower. The revised aircraft fulfilled the performance requirements and production was greenlighted under the designation " BB-1". In 1940, the M-87 series engine was supplanted by the better M-88 series. It was by this time that the BB-1 was re-designated to the commonly known "Su-2" designation, taking on the Sukhoi name and becoming the first aircraft design credited to the Sukhoi name - a name that would ultimately spawn such Cold War jet-powered performers as the successful "Fitter" and impressive "Flanker" series.
Design of the Su-2 revolved around its forward-placed radial piston engine. The engine powered a three-blade propeller capped by a conical spinner. Wings were low-mounted monoplane assemblies fitted to the middle portion of the fuselage and made primarily of duralumin. The fuselage featured internal workings made of wood and covered over in plywood. Resources were tight across Russia at the time and the prospect of an "all-metal" constructed fighter was far from a reality (at least for the time being). The two-man cockpit was housed under a "greenhouse" style framing that allowed for adequate views but the cockpit as a whole was set some distance aft of the engine compartment. The rear gunner sat in a ball-style turret emplacement to the rear of the pilot. The turret itself was powered by hand and featured a less-than-stellar arc of fire. Both crewmembers were protected to an extent by the use of armoring (up to 9mm thick) throughout the cockpit. The fuselage tapered off into a conventional empennage with a single rounded vertical tail fin and a pair of horizontal planes covered over in fabric. The undercarriage was wholly-retractable and was made up of two main landing gear legs and a single-wheeled tail wheel at rear. Armament varied from model to model but generally consisted of forward-firing fixed 7.62mm ShKAS machine guns in the wings and a 7.62mm machine gun in the rear turret. Some sported an additional 7.62mm machine gun along the cabin floor. To make the Su-2 a viable strike aircraft, the fighter had four underwing hardpoints designed for carrying drop bombs (up to 800lbs) or 10 / 20 x RS-82 / RS-132 series rockets respectively.
The Su-2 In-Action
Though a serviceable battlefield performer at the outset, the Su-2 was quickly done in by the changing face of war. Germany turned away from traditional ground support tactics and, instead, called upon fast-responding and better-performing single-seat, single-engine fighters to help their advancing hordes. The Su-2 was wholly outmatched no thanks to its inherent awkward qualities. The engine was addressed once again, this time in the form of the Shvetsov M-88B radial engine of 1,000 horsepower but did little to stem losses.
The Su-2 was under-armed, featured little in the way of defensive capabilities and fielded performance specifications well below what the Germans were matching against it. In their low-level attacks, many a Su-2 fell victim to accurate and lethal German ground-based flak attacks. Couple the lack-luster performance with the ill-trained aircrew that the Soviet's were relying on at the time and one produces a recipe for disaster.
However, 1941 proved a most critical year for the Red Empire. The Russians were in a desperate fight against Germany and any air-capable system was thrown into the fray - fielded in a macabre fight against overwhelming odds. The engine was once again upgraded to a new Shvetsov M-82 air-cooled radial of 1,520 horsepower. The M-82 now offered up performance specifications that included a top speed of 300 miles per hour, a service ceiling of 27,560 feet and an operational range of 685 miles.
In many further Su-2 production forms, the rear turret was removed entirely to save on weight and delete the uselessness of the hand-cranked turret with its simple defensive machine gun armament. Despite the changes, the aircraft saw little ongoing success. Nevertheless, Soviet High Command pressed the system to the extreme and even set about arming the type with drop bombs and rockets in what turned out to be suicide missions for her pilots.
The ShB was a proposed ground-attack variant fitting the M-88A series radial piston engine. The landing gears were revised and the total ordnance load was increased to 1,235lbs. However, the IL-2 was finally taking hold along the production lines and there was little need for the outclassed ShB. A such, the variant never entered production. The Su-4 became a short-lived improved form of the Su-2 fitting the M-82 engine. Armament was slightly improved by the addition of 2 x 12.7mm Berezin UB heavy caliber machine guns replacing the 4 x 7.62mm ShKAS systems in the wings. Sources also state an abandoned "Su-6" development which would have been another improved form, this time the Su-2 would have been redesigned from the ground up.
The End of the Line
Mercy for the Su-2 inevitably emerged with the quantitative arrival of the Ilyushin Il-2 "Shturmovik". This new single-engine, two-seat ground-attack fighter came as a godsend to the Soviets and went on to secure a legacy as one of the most important aircraft of World War 2. On the other hand, history would not be so kind to Pavel Sukhoi's first design for the Su-2 was quickly dropped from meaningful production by the middle of 1942. Many Su-2's ended their service careers in second-line duties or as emergency fighters when needed. In the bombing role, the Su-2 was superseded by the Tupolev Tu-2 and Petlyakov Pe-2 series.