Ilyushin Il-10
The Ilyushin Il-10 (Cyrillic Илью́шин Ил-10, NATO reporting name: "Beast") was a Soviet ground attack aircraft developed at the end of World War II by the Ilyushin construction bureau. It was also license-built in Czechoslovakia by Avia as the Avia B-33. Development. From the start of Eastern Front combat in World War II, the Soviet Air Force (VVS) used the successful ground attack aircraft Ilyushin Il-2 Sturmovik, powered by the Mikulin AM-38 inline engine. As the war progressed, the Soviets laid plans for that aircraft's successor. The main goal was to increase speed and maneuverability at  low altitudes, mainly to evade small-caliber anti-aircraft artillery, which was the main threat for ground attack aircraft, and to remove some of the Il-2's faults. The most promising project was a modern, light and maneuverable close assault aircraft, the Sukhoi Su-6, developed by Pavel Sukhoi's bureau from 1942. At the same time, Sergei Ilyushin developed a heavier aircraft, the BSh M-71, (Il-8 M-71), derived from the Il-2 design, on which it was partly based, to be powered by the prototype Tumansky M-71 radial engine, which did not enter production. In 1943, Ilyushin started work on a  new aircraft, Il-1, which was to be a 1- or 2-seat heavily armoured fighter-interceptor, meant mainly for fighting enemy bombers and transports. The Il-1 was similar to the Il-2 design, but was more modern, compact, and powered with a new Mikulin engine: the AM-42. But the VVS gave up the idea of heavy armoured fighters, due to their low speed, which was not enough to intercept modern bombers. As a result, Ilyushin decided to turn the Il-1 into a two-seat ground attack plane, with the designation changed to Il-10 in early 1944 (odd numbers were reserved for  fighters). At that time, Ilyushin also finished a prototype of a heavier ground attack plane, the Il-8, using the same engine, and more closely derived from the Il-2. It carried a higher payload (1,000 kg/2,204 lb), but had lower performance than the Il-10. Both types first flew in April 1944, the Il-10 proving greatly superior to the Il-8, which had poor handling. The Il-10 successfully passed trials in early June 1944. The third competitor was a new variant of the Sukhoi Su-6, also powered by the AM-42 engine. After comparative tests, the Il-10 was considered the winner and was chosen  as the new ground attack plane, despite some opinions that the Su-6 was a better aircraft, notwithstanding inferior performance and payload, with better gun armament. Notably, the Su-6 prototype was tested with maximum payload, causing lowered performance, while the Il-10 was tested with normal payload. Some advantages of the Il-10 came from its technical similarity to the Il-2. Production. On 23 August 1944 the Il-10 was ordered into serial production by decision of the State Defense Committee (GKO) as a new ground attack plane. Its armament was initially similar to late model Il-2s, with two 23 mm VYa-23 cannons and  two ShKAS machine guns in the wings, and a 12.7 mm UBT machine gun for a rear gunner, and 400 kg, or a maximum 600 kg of bombs. Unlike the Il-2 and Su-6, it was not initially meant to carry rockets. Production of the Il-10 started in Kuybyshev's factories No. 1 and No. 18. The first production aircraft flew on 27 September 1944 and 99 aircraft were produced by the end of 1944. Early series aircraft showed teething problems, most notably engine faults and fires. Most problems were eliminated by 1945. Aircraft produced from April 1945 onwards could carry  four unguided air-to-ground rockets. Aircraft produced from 1947 onwards were fitted with stronger armament, consisting of four 23 mm NS-23 cannons in the wings and a 20 mm cannon for the rear gunner. Il-10 production ended in 1949, after a run of 4,600 aircraft; in the last two years, they were produced in factory No. 64. Between 1945 and 1947, 280 UIl-2 or Il-10U trainer variants were produced. The rear gunner' cockpit was replaced with a longer instructor's cockpit with dual controls. Its performance and construction were similar to the combat variant apart from armament, which was  reduced to two cannons, two rockets, and a standard load of bombs. In 1951, the Czechoslovak firm Avia secured a license to make Il-10s, with the designation B-33. The first one flew on 26 December 1951. Initially, their engines were Soviet-built. From 1952 onwards the engines were also produced in Czechoslovakia as the M-42. Besides the combat variant, a Czechoslovak trainer variant also entered service under the designation CB-33. In total, 1,200 B-33s were built by 1956. In 1951, due to experience acquired during the Korean War, the Soviet Air Force decided that propeller ground attack aircraft might still  be useful, and decided to renew Il-10 production in a modified variant, the Il-10M, which first flew on 2 July 1951. It was slightly longer, with a wider wingspan, and larger control surfaces, with a fin under the tail. Four of the more recently developed NR-23 cannons were mounted in the wings, while the payload stayed the same, and newer navigation equipment was installed, giving partial all-weather capability. Speed decreased slightly, but handling improved. Between 1953 and 1954, 146 Il-10Ms were made, all but 10 in Rostov-on-Don's factory No.168. In total, 6,166 of all Il-10  variants were made, including those built under license. Trials of Il-10s mounted with more powerful AM-43 and AM-45 engines took place, but proved unsuccessful. Ilyushin next designed a lighter close support aircraft, the Il-16, with improved performance and similar armament. It first flew on 10 June 1945. A short run entered production, but the project was cancelled in 1946 due to the AM-43 engine's unreliability. Design. Technical description. The airframe was a one engine two-seat monoplane, with a metal-covered frame. It was highly armoured. The front part of the fuselage, with the cockpit, was a shell of  armour plates 4–8 mm thick; the thickest, 8 mm, were under the engine, there was no armour above the engine. The front windshield was made of armour glass 64 mm (2.5 in) thick. Also armoured were: the roof above the pilot, side window frames in the pilot's cab, the wall between crew seats, and the rear wall behind the cab. Total armour weight was 994 kg, including its attachment. The wing consisted of a central section, with two bomb bays, and two detachable outer panels. The undercarriage was retractable. The main wheels folded to the rear after rotating by  86°. Early Il-10s had two 23 mm VYa-23 autocannons (150 rounds each) and 2 7.62 mm ShKAS machine guns (750 rounds each) fixed in the wings, and a 12.7 mm UBT machine gun in a rear gunner station BU-8, with 150 rounds. The horizontal angle of the rear machine gun field of fire was 100°. From 1947, the aircraft were armed with four NS-23 23 mm cannons in the wings (150 rounds each) and 20 mm B-20T cannon in a rear gunner station BU-9 (150 rounds). The IL-10M had four 23 mm NR-23 cannons in wings  (150 rounds each) and 20 mm B-20EN cannon in a rear gunner station BU-9M (150 rounds). Avia B-33 had four 23 mm NS-23RM cannons in wings and 20 mm B-20ET cannon in a rear gunner station BU-9M. The normal bomb load was 400 kg, maximum load was 600 kg. This could be small fragmentation or anti-tank bomblets, put in bomb bays, or four 50–100 kg bombs in bomb bays and externally under wings, or two 200–250 kg bombs attached under wings. Small bomblets were put directly on bomb bay floors, in piles. A typical load was 182 (maximum  200) 2 kg AO-2,5-2 fragmentation bombs, or 144 PTAB-2,5-1,5 anti-tank HEAT bombs. Apart from bombs, four unguided rockets RS-82 or RS-132 could be carried on rail launchers under wings. Avia B-33s were also fitted to carry other rocket types. Late Soviet aircraft could carry ORO-82 and ORO-132 tube launchers. In the tail section was a DAG-10 launcher with 10 anti-aircraft or anti-personnel grenades AG-2 (after being thrown, they would fall with parachutes and then burst, but were not widely used in practice). The Il-10 engine was a 12-cylinder inline V engine Mikulin AM-42, liquid -cooled, power: 1,770 hp continuous, takeoff power: 2,000 hp. Three-blade propeller AV-5L-24 of 3.6 m diameter. Two fuel tanks in the fuselage: upper 440 l over engine, ahead of the cockpit, and lower tank of 290 l under the cockpit. The aircraft had a radio set and a camera AFA-1M in a rear section of the fuselage. Operational history. In October 1944, the Il-10 first entered service with training units in the Soviet Air Force. In January 1945, the first Il-10 combat unit entered service with the 78th Guards Assault Aviation Regiment, but it did not enter action  due to unfinished training. However, three other Il-10 units managed to take part in the final combat actions of World War II in Europe. They were the 571st Assault Aviation Regiment (from 15 April 1945), the 108th Guards Assault Aviation Regiment (from 16 April 1945), and the 118th Guards Assault Aviation Regiment (on 8 May 1945). About a dozen aircraft were destroyed by flak or engine breakdowns, but the Il-10 appeared to be a successful design. One was shot down by an Fw 190 fighter, but a crew of the 118th Regiment shot down another Fw 190 and probably damaged  another. On 10 May 1945, the day after the official Soviet end of the war, (Victory Day), there were 120 serviceable Il-10s in Soviet Air Force combat units, and 26 disabled ones. After the USSR reentered the war against the Empire of Japan, with the invasion of Manchuria, from 9 August 1945, one Il-10 unit, the 26th Assault Aviation Regiment of the Pacific Navy Aviation, was used in combat in the Korean Peninsula, attacking Japanese ships in Rasin and rail transports. After the war, until the early 1950s, the Il-10 was a basic Soviet ground attack aircraft. It was withdrawn  from service in 1956. At the same time, work on new jet-powered dedicated armoured ground attack planes (like the Il-40) was canceled, and the Soviets turned to multipurpose fighter-bomber aviation. The Il-10 and its licensed variant, the Avia B-33, became a basic ground attack plane of the Warsaw Pact countries. From 1949 to 1959, the Polish Air Force used 120 Il-10s (including 24 UIl-10), and 281 B-33s. In Poland, the B-33 was modified to carry 400 l fuel tanks under its wings. From 1950 to 1960, Czechoslovakia used 86 Il-10s, including six UIl-10s, and about 600 B-33s. From  1949 to 1956, the Hungarian Air Force used 159 Il-10s and B-33s. From 1950 to 1960, the Romanian Air Force used 14 Il-10s and 156 B-33s. Bulgaria also used these aircraft. In the late 1940s, 93 Il-10 and UIl-10s were given to North Korea. They were then used in the 57th Assault Aviation Regiment during the early phase of the Korean War. They were initially used with success against the weak anti-aircraft defense of South Korean forces (following the US refusal to supply the south with "heavy weapons"), but then they suffered heavy losses in encounters against the United  States Air Force fighters and were bombed on the ground themselves. After several weeks, about 20 remained. In the summer of 1950, North Korea received more aircraft from the USSR. The North Koreans claimed that they sank a warship on 22 August 1950 with Il-10s, but it was never confirmed. From 1950, Il-10s were used by the People's Republic of China, in two regiments of an assault aviation division. They were used in combat during a conflict with the Republic of China, (Taiwan), over border islands in January 1955. They remained in service until 1972 (replaced by Nanchang Q-5 ). From 1957, Yemen used 24 B-33s. Kemlitz incident. On 14 April 1951 a flight of Soviet Il-10 aircraft of the 16th Air Army departed Reinsdorf for the bombing and strafing range at Lieberoser Heide. Thirteen aircraft crashed across a wide area in the vicinity of Kemlitz for the loss of 26 aircrew. The cause of the disaster – whether sabotage, a fueling error, or something else – remains publicly unknown. The aircrew are buried at the Soviet Cemetery Potsdam. In April 2011 a memorial stone was erected in the village square at Kemlitz.