Antonov An-2
The Antonov An-2 ("kukuruznik"—corn crop duster; USAF/DoD reporting name Type 22, NATO reporting name Colt) is a Soviet mass-produced single-engine biplane utility/agricultural aircraft designed and manufactured by the Antonov Design Bureau beginning in 1947. Its remarkable durability, high lifting power, and ability to take off and land from poor runways have given it a long service life. The An-2 was produced up to 2001 and remains in service with military and civilian operators around the world. The An-2 was designed as a utility aircraft for use in forestry and agriculture. However, the basic airframe  is highly adaptable and numerous variants of the type have been developed; these include hopper-equipped versions for crop-dusting, scientific versions for atmospheric sampling, water-bombers for fighting forest-fires, flying ambulances, float-equipped seaplane versions and lightly armed combat versions for dropping paratroops. The most common version is the An-2T 12-seater passenger aircraft. All versions (other than the An-3 and the An-2-100) are powered by a nine-cylinder Shvetsov ASh-62 radial engine, which was developed from the Wright R-1820. The An-2 typically consumes . Design and development. Origins. The Antonov An-2 was designed to meet a  1940's Soviet Ministry of Forestry requirement for a replacement for the much lighter, largely wooden-airframed Polikarpov Po-2, which was used in large numbers in both agricultural and utility roles. Antonov designed a large single bay biplane of all-metal construction, with an enclosed cockpit and a cabin with seats for twelve passengers. The first prototype, designated SKh-1 and powered by a Shvetsov ASh-21 radial engine, flew on 31 August 1929. The second prototype was fitted with a more powerful Shvetsov ASh-62 engine, which allowed the aircraft's payload to be significantly increased from , and in this form it  was ordered into production. Initial Soviet production was at State Factory 473 in Kiev, Ukrainian SSR, where the bulk of up to 5,000 units had been produced by 1960. Later Soviet production (after 1965, of model An-2M especially) was at State Factory 464 at Dolgoprudniy, Russian SFSR. After 1960, however, most An-2s were constructed at Poland's WSK factory in Mielec; it is believed that over 13,000 aircraft were built in Poland before principal manufacturing activity ended during 1991. However, up until 2001, limited production was undertaken using remaining stocks of components, spares and maintenance coverage, such as a  small batch of four aircraft that were produced for Vietnam. China also builds the An-2 under licence as the Shijiazhuang Y-5. It has been occasionally and erroneously reported that there was East German production of the An-2, however, while An-2s often underwent extensive refurbishment in East German facilities, no new aircraft were constructed there. The An-2 is commonly used as a light utility transport, parachute drop aircraft, agricultural work and other tasks suited to a large slow biplane. Its slow flight and good short field performance make it suited for short, unimproved fields, and some specialized variants have also been  built for cold weather and other extreme environments. The "Guinness Book of World Records" states that the 45-year production run for the An-2 was for a time the longest ever for any aircraft and challenged the well over two decades-long run of the much lighter, late-1920s origin Polikarpov Po-2 biplane it was intended to replace. But the An-2's production duration run record was exceeded by the four-turboprop, 1954-origin, Lockheed C-130 Hercules military transport. Further development. During the early 1980s, Antonov experimented with a development of the An-2 powered by a modern turboprop engine. The unit  used was a Glushenkov engine. Aircraft fitted with this engine had a longer, more streamlined nose to accommodate it. It received the designation of Antonov An-3. During 2013, Antonov announced that it had successfully flown for the first time a new version of the An-2, dubbed the "An-2-100", which was fitted with a three-blade reversible propeller and a Motor Sich MS-14 turboprop running on kerosene rather than Avgas, which is no longer produced in CIS countries. That same year, the company stated that it had received orders for upgrading "hundreds" of the An-2 planes still in operation in  Azerbaijan, Cuba and Russia to the An-2-100 upgrade version. The Siberian Research Institute of Aviation (SIBNIA) has test flown a highly modified Antonov An-2 with carbon fibre winglet-like braces and carbon fibre wing structures. It was equipped with a five-bladed turboprop engine, most probably the Honeywell TPE331 already installed on a modernized version of the An-2 that entered service in 2014. According to Russian aviation company Sukhoi, this aircraft was built to demonstrate the aerodynamic and structural changes that were planned for an eventual An-2 replacement announced on 10 June 2015. The autoclave-cured carbonfibre composite materials  – including wing panels, spars and ribs – were produced by the Novosibirsk Aviation Plant. Sukhoi says the design change improved the speed of the An-2 by 50%, and testing also has shown the minimum flying speed of the aircraft is "close to zero". Design. The Antonov An-2 is a mass-produced single-engine biplane that has been commonly used as a utility and agricultural aircraft. It is deliberately furnished with a minimum of complex systems. The crucial wing leading edge slats that give the aircraft its slow flight ability are fully automatic, being held closed by the airflow over the wings . Once the airspeed drops below , the slats will extend because they are on elastic rubber springs. Under typical conditions, the take-off is complete within while the landing run requires ; these figures will vary dependent upon various factors, such as the aircraft's take-off/landing weight, the external air temperature, surface roughness, and headwind. The An-2 is equipped with various design features which make it suitable for operation in remote areas with unsurfaced airstrips. It is fitted with a pneumatic brake system (similar to those used on heavy road vehicles) to stop on short runways, along with an air  line attached to the compressor, so the pressure in the tires and shock absorbers can be adjusted without the need for installing specialised equipment. The batteries, while sizable, are relatively easy to remove, so the aircraft does not need a ground power unit to supply power for starting the engine. Likewise, there is no need for an external fuel pump to refuel the aircraft as it is provided with an inbuilt onboard pump, which allows the tanks to be filled from simple fuel drums. The An-2 has no stall speed, a fact which is quoted in the operating handbook. A  note from the pilot's handbook reads: "If the engine quits in instrument conditions or at night, the pilot should pull the control column full aft and keep the wings level. The leading-edge slats will snap out at about and when the airplane slows to a forward speed of about , the airplane will sink at about a parachute descent rate until the aircraft hits the ground." As such, pilots of the An-2 have stated that they are capable of flying the aircraft in full control at (as a contrast, a Cessna four-seater light aircraft has a stall speed  of around ). This slow stall speed makes it possible for the aircraft to fly backwards relative to the ground: if the aircraft is pointed into a headwind of roughly , it will travel backwards at whilst under full control. The An-2's ability, looks and flying characteristics, and its status as one of the world's biggest single-engined production biplanes, mean that demand for the An-2 is increasing in Western Europe and the United States, where they are prized by collectors of classic aircraft, making it an increasingly common sight at airshows. Many western countries prohibit the use of the  An-2 commercially because the aircraft has not been certified by the relevant national aviation authorities. These restrictions vary by country, but all prevent the An-2 being used for any 'for profit' purpose, with the exception of the United States, where An-2s imported since 1993 are limited to experimental certification, but PZL-built An-2s are exempt from this restriction due to a bilateral agreement with Poland. Operational history. Military service. The An-2 was adopted in bulk by both the Soviet Air Force and other Eastern Bloc military forces. It was first used in a military context during the Korean War of  the early 1950s. The Vietnam People's Air Force (VPAF) was another prolific user of the AN-2; during the Vietnam War, the service occasionally used the type as an attack aircraft. During the 1960s, a single An-2 that was attempting to engage South Vietnamese naval units was shot down by a United States Air Force McDonnell Douglas F-4 Phantom II fighter, under the control of an Air Intercept Controller on the . On 12 January 1968, a clandestine TACAN site (call sign: "Lima Site 85"/Phou Pha Ti) installed by the United States Air Force in Northern Laos for directing USAF warplanes  flying from Thailand to Vietnam was attacked by three North Vietnamese An-2s. A pair of An-2s fired on the outpost using a mixture of machine guns and rockets while a third An-2 orbited overhead to survey the assault. An Air America Bell UH-1B, XW-PHF that had been resupplying the site gave chase to the two attacking aircraft. Using an AK-47, the American crew (Ted Moore Captain, Glen Wood Kicker) succeeded in shooting down one of the An-2s while the second aircraft was forced down by combined ground and air fire, eventually crashing into a mountain. The surviving Antonov returned  to its home base, Gia Lam, near Hanoi. During the Croatian War of Independence in 1991, a number of aged An-2 biplanes previously used for crop-spraying were converted by the Croatian Air Force to drop makeshift barrel bombs. They were also used to conduct supply missions to the town of Vukovar and other besieged parts of Croatia. The chief advantage for the An-2 was that they could take off and land in small or improvised airstrips. They were also frequently used to drop supplies by parachute on isolated garrisons. At least one AN-2 was shot down on 2 December  1991 over Vinkovci, eastern Slavonia, by a Serbian surface to air missile (SAM) emplacement which purportedly launched a salvo of SA-6s at the aircraft. Following the shootdown, the flights over Serbian lines ceased, due to the presence of Serb SA-6's. The previous radar guided AA systems were avoided by keeping the airplane's speed below , the speed of objects that radars were programmed to erase from the screen. Reportedly, North Korea has operated a number of the AN-2s. The Korean People's Army Special Operation Force is known to use the An-2 to facilitate the infiltration of paratroopers. It  has been speculated that in wartime, these aircraft could possibly be used to deliver troops behind enemy lines for sabotage operations. As October, 2020 during the ongoing 2020 Nagorno-Karabakh war Azerbaijan Forces have been operating unmanned AN-2 for surveillance and bombing of Armenian defenses, however the type of the drone remaining unknown for Armenian sources. Armenian forces revealed footage of the alleged shotdown of Azerbaijani An-2, according to video evidence at least 11 An-2 have been destroyed, with 10 confirmed as shot down and one crashing after takeoff. On March 2, 2022, Russian An-2s were observed being stationed at  Seshcha Air Base, Bryansk Oblast. As the base is situated close to the border with Ukraine, it has been speculated that the aircraft are to be used as part of the ongoing 2022 Russian invasion of Ukraine. Civil aviation. Over the years, dozens of nations and companies alike have employed the An-2 in civil roles. The type was heavily used throughout the Soviet Union and the Eastern Bloc nations; in particular, Russian airline Aeroflot has operated a large number of the An-2s. During the Soviet era, the An-2 was used as a short-range airliner in Estonia, performing regular flights  between the towns of Kuressaare and Kärdla, which reside on separate islands, Saaremaa and Hiiumaa. Since the collapse of the Soviet Union and the various communist states of Eastern European, most airlines in these regions have been withdrawing their An-2s from service. This is due to some of these aircraft being over 40 years old, as well as a result of the decline in the production of avgas to fuel the type. Private operators are typically still using the An-2s, as their stability, capacity and slow-flying ability has made them relatively popular for some functions, such as for skydiving . Whilst their relatively high noise levels, increasing maintenance costs, high fuel consumption and unsophisticated nature (the pre-flight checks alone take between 30 and 40 minutes) has rendered them obsolete for the majority of commercial routes in Europe, the large number of aircraft available means that unit prices are especially low in comparison to contemporaries (being available from as little as US$30,000 for a serviceable example). The price factor has made them highly attractive for continued use in the developing world, where their ability to carry large loads into short airstrips makes them assets to airlines on a budget . Many ex-Aeroflot An-2s have since found work with regional operators across Africa, Central and South America, Cuba and southeast Asia. In recent years, the An-2 has also gained popularity in the U.S. and Canada, where it has often been used as a bushplane. Because of their reliability and robustness, several operators have continued to use the type to conduct scheduled passenger service between airstrips in Western countries; one example of such use being the air service between the North Sea islands of Sylt and Föhr. As of 2015, there were thousands of An-2s remaining in operation around the world , including over 1,500 in Russia, 294 in Kazakhstan and 54 in Ukraine. Operators. The aircraft is popular with air charter companies and small airlines, and is operated by private individuals and companies. Accidents and incidents. As of 19 December 2017 there have been 622 An-2 hull-loss accidents, claiming a total of 774 lives. One of the most recent accidents occurred around 15:00 on 2 July 2017 in the Black Sea, when an Antonov An-2R operated by Albatros crashed in the Kiliya District, Ukraine during an aerial application flight; both pilots survived. In the second known post-WWII act of  suicide by pilot, on September 26, 1976, Russian national Vladimir Serkov made an unauthorized takeoff with an Antonov An-2 (Reg # USSR-79868) from Novosibirsk-Severny Airport. He crashed the aircraft into the stairwell of an apartment complex at Stepnaya st., house 43 / 1, where his ex-wife's parents lived, in an attempt to kill his ex-wife. After completing two laps around the scene, Serkov attempted to pilot the plane to the parents' apartment where his wife and two-year-old son were visiting. The aircraft pierced the stairwell between the 3rd and 4th floors, and being fueled with 800  liters of gasoline, ignited a large fire inside the stairwell that ultimately spread to damage 30 total apartments. Firefighters were on scene in five minutes, taking 57 minutes to extinguish the blaze. A four-year-old and two six-year-old children were killed at the scene from burns. Another four-year-old child died eight days later as a result of burns. In total, 11 residents were injured as a result of fire burns. Serkov's ex-wife (and her parents) and his toddler son were not injured in the incident. The first known post-WWII act of suicide  by pilot was also with an Antonov An-2. Timofei Shovkunov stole an An-2 and flew it directly into his apartment building in Voroshilovgrad (now Luhansk) on March 27, 1972, apparently despondent after his wife having left along with his son the day before. He was the lone casualty.