Antonov An-2

Antonov An-2

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http://en.wikipedia.org/wiki/Antonov_An-2

An-2 / Y-5

An-2 of Polish Air Force
Role	STOL Agricultural and utility aircraft
Manufacturer	Antonov WSK PZL-Mielec Shijiazhuang
Designed by	Oleg Antonov
First flight	1947^[1]
Status	Series production in China as Y-5
Primary users	Soviet Air Force Aeroflot North Korean Air Force Many others
Produced	1947-1992
Number built	18,000
Unit cost	As low as US$100,000
Variants	Antonov An-3

The Antonov An-2 (Russian nickname: кукуру́зник kukuruznik - a kolkhoz maize worker (inherited from Polikarpov Po-2)) also nicknamed "Annushka"; is an extremely durable, light, single-engine biplane which first flew on 31 August 1947 and was the first plane designed by Antonov. It is used as a light transport, capable of carrying 12 passengers, and for parachute drops and agricultural work. Its slow-flight and STOL capabilities 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 the longest ever, for any aircraft, only recently beaten by the Lockheed C-130 Hercules. (USAF/DoD reporting name Type 22,, NATO reporting name Colt).

Design and development

Private An-2 at the Miramar Air Show

The Antonov An-2 was designed to meet a 1947 Soviet requirement for a replacement for the Polikarpov Po-2 which was used in large numbers as both an agricultural aircraft and a utility aircraft. Antonov designed a large single bay biplane of all-metal construction, with an enclosed cockpit and a cabin with room for seats accommodating twelve passengers. The first prototype, designated SKh-1, and powered by a Shvetsov ASh-21 radial engine, flew on 31 August 1947. The second prototype was fitted with a more powerful Shvetsov ASh-62 engine, which allowed the aircraft's payload to be significantly increased from 1,300 kg (2,870 lb) to 2,140 kg (4,720 lb), and this form it was ordered into production.

By 1960 the USSR had produced over 5,000 units. Since 1960, most An-2s have been built at Poland's WSK factory in Mielec, with over 13,000 made there before full production ended in 1991. Limited production from parts stocks, as well as spares and maintenance coverage continued until 2001, when 4 aircraft were produced for Vietnam. China also builds the An-2 under license as the Shijiazhuang Y-5.

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 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, lightly armed combat versions for dropping paratroops, and of course the most common An-2T version, which is the 12-seater passenger aircraft. All versions (other than the An-3) are powered by a 750 kW (1,000 hp) 9-cylinder Shvetsov ASh-62 radial engine, which was developed from the Wright R-1820.

An-2 on skis at Volosovo air field, Moscow region

An-2 at Grand Junction aviation show.

The An-2 has design features which make it suitable for operation in remote areas with unsurfaced airstrips:

It has a pneumatic brake system (similar to those used on heavy road vehicles) to stop on short runways.
It has an air line fitted to the compressor, so the pressure in the tires and shock absorbers can be adjusted without the need for special equipment.
The batteries are large and easy to remove, so the aircraft does not need a ground power unit to supply power.
There is no need for an external fuel pump to refuel the aircraft, as it has an onboard pump that allows the tanks to be filled from simple fuel drums.
It has 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 64 km/h (40 mph), the slats will extend because they are on elastic rubber springs.
Take-off run: 170 m, landing run: 215 m (these numbers will of course vary depending on take-off/landing weight, outside air temperature, surface roughness, and headwind).

Private Lithuanian An-2

An interesting note from the pilot's handbook reads: "If the engine quits in instrument conditions (blind flying when you can't see the ground) or at night, the pilot should pull the control column full aft (it won't stall) and keep the wings level. The leading-edge slats will snap out at about 64 km/h (40 mph), and when the airplane slows to a forward speed of about 40 km/h (25 mph), the airplane will sink at about a parachute descent rate until the aircraft hits the ground."

The An-2 has no stall speed quoted in the operating handbook. Pilots of the An-2 say one can fly the aircraft in full control at 30 mph (as a contrast, a modern Cessna 4-seater light aircraft has a stall speed of around 55 mph). This slow stall speed makes it possible for the aircraft to fly backwards (if the aircraft is pointed into a headwind of, say, 35 mph (56 km/h), it will travel backwards at 5 mph (8.0 km/h) whilst under full control). (This is, of course, also possible with almost any other real Short Take Off and Landing (STOL) aircraft.)

Another private An-2 in the UK

Since the collapse of the Soviet Union and the Eastern European communist states, most airlines in these areas have been withdrawing their An-2s from service as some of these aircraft are now over 40 years old. Private operators are still using the planes as their stability, capacity and slow-flying ability make them very popular, for instance for skydiving.

In the early 1980s Antonov experimented with a development of the An-2 powered by a modern turboprop engine. The unit used was a 1,450 horsepower (1,080 kW) Glushenkov engine, and aircraft fitted with this engine were fitted with a longer, more streamlined nose to accommodate it. See Antonov An-3 article for more information.

Whilst their high noise levels, increasing maintenance costs, high fuel consumption and unsophisticated nature (the pre-flight checks alone take between 30 and 40 minutes) makes them obsolete in Europe, the huge number of aircraft available means that prices are low (from as little as $30,000 for a serviceable example). This makes them ideal for 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 work as regional airliners in Africa, Central and South America, Cuba and the Indian subcontinent.

Ukrainian Hryvna depicting the An-2 airplane

North Korea has a number of the aircraft.[6] It is believed that the wooden propellers and canvas wings on their variants (the Y-5 version license-built in China) give them a low radar cross-section, and therefore a limited degree of "stealth".[7] In a war they would probably be used to parachute or deliver special forces troops behind enemy lines for sabotage operations.

The An-2's ability, looks and flying characteristics, and its status as "The World's Biggest Biplane" mean that demand for the aircraft is increasing in the United States and Western Europe, where they are prized by collectors of classic aircraft. This makes the An-2 an increasingly common sight at airshows. However, in nearly all Western nations (the USA, Canada, the United Kingdom, France, Germany, etc.) one may not use the An-2 commercially (despite its obvious potential as a bush plane and parachute aircraft). This is because the aircraft has not been certified by the relevant national aviation authorities, which limits its use. These restrictions vary by country, but all prevent the An-2 being used for any 'for profit' purpose. In the United States, An-2s imported since 1993 are limited to flights within 300 miles (480 km) of their home airport, and may only land at that same airfield; the An-2s that PZL produced, however, are exempt due to a bilateral agreement with Poland, which, essentially, include any An-2 built after 1972 except Chinese Y-5, as at this time the production of the aircraft in Soviet Union ceased as per COMECON agreement.

Combat service

Initially used by combat service in Korean war. During the 1960s an An-2 attempting to engage South Vietnamese naval units was shot down by an F-4 Phantom II under the control of an Air Intercept Controller (AIC) on the USS Long Beach. The An-2 was used also during the Vietnam war as a Navy interceptor. This modification had two "Skvall" torpedoes under the wing and was difficult to detect due to its low-altitude flight. Even when detected it was difficult to intercept because the plane's cruise speed was 135-160 km/h (well below the landing speed of jet aircraft during the war).

On January 12, 1968, a clandestine TACAN site (call sign: Lima Site 85) installed by Special Forces (United States Army) in Northern Laos for directing USAF warplanes flying from Thailand to Vietnam was attacked by 3 North Vietnamese An-2s using machine guns fired from the cabin and hand thrown grenades. An Air America Bell UH-1B flying in the vicinity was radioed for help and chased the flight of 3 aircraft. By using a carbine the American crew succeeded to shoot down one of the An-2 while the second aircraft was forced down and crashed into a mountain. The surviving Antonov was later chased minutes before the border by another Air America helicopter and was forced down to ground too.

During the Croatian War of Independence in 1991, a few old Antonov An-2 biplane used for crop-spraying were converted to drop makeshift bombs and were used in supply missions to the besieged town of Vukovar.

Variants

An-2 variants

Antonov An-2E WIG

Sources:

Soviet/Russian production

SKh-1 — the original designation of the An-2
An-2F — experimental artillery-observation with a revised twin-tail, under-fuselage observer's position and defensive machine-gun dorsal position[8]
An-2L — fire-fighting with chemicals
An-2LV — Lesnoj Vodnyj (forest hydroplane), firefighting waterbomber
An-2M — modifizirovannij, modified agricultural version (developed by Beriev)
An-2P — passazhirskij, passenger version
An-2P — protivopozharnij, fire-fighting with water
An-2S — ambulance
An-2V — seaplane version, also known as An-4[9]
An-2VA — water bomber
An-2ZA — Zondirovanie Atmosfery (atmosphere sampling), high altitude meteorological research (also known as An-6 Meteo)[10]
An-2E — Ekranoplan conversion (Russian: Ан-2Э) [11] [12]

Russian/Ukrainian production

An-3 — New-build turboprop derived from An-2 that has spawned its own line of sub-variants

Polish production

An-2 Geofiz or An-2Geo — Geofiz geophysical model
An-2D5 — VlP transport with 5 seats
An-2D6 — VlP transport with 6 seats
An-2T — Polish version of initial An-2 model
An-2M or An-2W — Polish version of An-2V floatplane[13]
An-2P — passenger version with 12 seats with better soundproofing and propeller
An-2P Photo — Special version equipped for photogrammetric operators.
An-2PK — VlP transport with 5 seats prepared to usage in Arctic climate
An-2PF — modified for photography
An-2PR or An-2PRTV — TV relay work (PR for Polish Radio, TV for television)
An-2R — agricultural model with tank for 1.300 kg chemical substanions
An-2S — ambulance with 6 seats
An-2TD — paratrooper version with 12 seats
An-2TP — passenger/cargo, modified from An-2TD
An-2TPS - — ambulance derrived forim An-2TP in 1974
An-3M — prototype with turboprop engine TWD-20 (1054 kW/1432 KM) built with some components from the PZL-106 Kruk
Lala-1 — experimental version with revised, open-frame tail to accommodate turbofan engine; used as development model for M-15 Belphegor agricultural aircraft.[14] [15] Pictures [16] [17] [18]

Antonov An-2 converted into a WIG

Chinese production

Y-5 — Chinese version of An-2, initially built from Soviet blueprints and with supervision from Soviet advisors.[19]
Y-5A — First mass-produced Chinese version, light passenger transport [20]
Y-5B — Improved version introducing avionics upgrades and a new engine; some built as paratrooper transports [21]
Y-5C — Amphibian version of Y-5A [22]
Y-5D — Bomber crew trainer

Cockpit of a 1971 ex-Aeroflot An-2 at the Historic Aircraft Restoration Museum. See also [5] for a very high resolution image of this cockpit.

Antonov An-6

The An-6 "Meteo" was a high-altitude weather reconnaissance aircraft based on the An-2. It featured an extra glass cockpit just near the vertical stabilizer.

Operators

Antonov An-6

In addition to Aeroflot, the Soviet Air Force, and other Eastern Bloc military forces, dozens of nations and airlines have employed the An-2 in civil and military roles.

Specifications (An-2)

Data from

General characteristics

Crew: 1-2
Capacity: 12 passengers
Length: 12.4 m (40 ft 8 in)
Wingspan:
- Upper wing: 18.2 m (59 ft 8 in)
- Lower wing: 14.2 m (46 ft 9 in)
Height: 4.1 m (13 ft)
Wing area: 71.52 m² (769.8 ft²)
Empty weight: 3,300 kg (7,300 lb)
Loaded weight: 5,500 kg (12,000 lb)
Useful load: 2,140 kg ()
Powerplant: 1× Shvetsov ASh-62R 9-cylinder supercharged radial engine, 750 kW (1,000 hp)

Performance

Maximum speed: 258 km/h (139 kn, 160 mph)
Cruise speed: 190 km/h (100 kn, 120 mph)
Stall speed: ~50 km/h (26 knots, 30 mph)
Range: 845 km (456 nmi, 525 mi)
Service ceiling: 4,500 m (14,750 ft)
Rate of climb: 3.5 m/s (700 ft/min)
Power/mass: 140 W/kg (0.83 hp/lb)

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Published in July 2009.

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