HISTORY OF THE AN2
The Antonov An-2 is an extremely durable, relatively light, single-engine biplane which first flew in 1947. It is used as a light transport, parachute drops and agricultural work. Its extraordinary slow-flight capabilities make it supremely suited for short, unimproved fields, and some specialized variants have also been built for cold weather and other extreme environments.
The An-2 is the largest single-engine biplane ever produced and still flying. It was produced in great numbers; over 5,000 were built in the USSR. Since 1960, most An-2's have been built at Poland's PZL factory in Mielec, with over 12,000 made before full production ended in 1992. Limited production from part stocks continues. The An-2 is also built under license in China as the Shijiazhuang Y-5.
The An-2 was designed as a utility aircraft for use in government-owned 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 para-troops, and of course the most common An-2T version, which is the 12-seater passenger aircraft.
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) allowing it 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 'in the field'.
-The batteries are large and easy to remove, meaning that the aircraft does not need a ground power unit to supply power.
-It has it has an onboard fuel pump that allows the fuel tanks to be filled from simple fuel drums on the ground.
-It has the minimum of complex systems. For example, the crucial wing leading edge slats that give the An-2 its slow flight ability are automatic, being held closed by airflow over the wings. Below 40 mph (64 km/h), they extend as they are on elastic rubber springs.
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 40 mph (64 km/h), and when the airplane slows to a forward speed of about 25 mph [40 km/h], 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 handbooks (the stall speed being the speed at which the aircraft is travelling too slowly for the airflow over the wings to keep it aloft). Pilots of the An-2 say the aircraft can be flown 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, it will travel backwards at 5 mph whilst under full control). This is a rare ability, even amongst other Short Take Off and Landing (STOL) aircraft. Only the German Fieseler Fi156 'Stork' of World War II has better slow-speed ability.
Aircraft was designed by Oleg Konstantinovich Antonov at Kiev for utility transport use requiring short field performance.
HA-MKF was manufactured in 1980 by PZL-Mielec in Poland.
Power Plant: WSK-PZL-Kalisz (Wytwornia Sprzetu Komunikacyjnego-PZL-Kalisz) Shvetsov ASz-62 IR Geared 9 Cylinder 1823 Cu. In. Radial Engine, rated at 1000 HP max, driving a 4 blade AW-2 Propeller.
Take-Off Power : 1000 HP at 2200 RPM = 110 gallons/hr = 500 litres/hr 5 minutes max.
Rated Power: 820 HP at 2100 RPM
Max. Continuous: 738 HP at 2030 RPM
75% Power : 615 HP at 1910 RPM
50% Cruise : 410 HP at 1670 RPM = 45 gallons/hr = 200 litres/hr
Propeller Gear Ratio : 0.637 to 1 11:16
1800 RPM and 800 mm Hg manifold pressure for typical climb.
1600 RPM and 700 mm Hg for typical cruise.
Use 100 Octane Aviation Grade minimum.
The wings are of an unequal span single bay biplane design, all metal construction, with fabric covering. The wing area is 770 square feet total. Note: wings have full length leading edge slats and ailerons droop with flap actuation to provide great STOL performance. The fuselage is of all-metal stressed skin semi-monocoque construction. The tail is a braced all metal structure with fabric covering.
Ailerons, rudder, and elevators are all manually controlled with pushrods and cables. Flaps and trim electrically operated. Automatic leading edge slats provide excellent slow speed safety and high lift.
Conventional configuration (tail wheel design) with split axle, long stroke oleo shock absorbers on the main mounts and a fully castoring and self centring tail wheel. Brakes are pneumatically operated.
Crew: Normally two pilots, may be flown single pilot when no passengers are aboard.
Length = 41 feet, 9 inches; Wing Span = 59 feet, 8 inches; Height = 13 feet, 2 inches (tail down). Total Wing Lift Area = 256.6 sq. ft. (156.2 upper, 100.4 lower). Cargo compartment = 13.5 feet long by 5 feet wide by 5.9 feet tall (398.25 cubic feet). Cargo door opening - 4.5 feet wide by 5 feet tall.
Empty = 7,600 lbs.; Max Take Off = 12,125 lbs.; Max Landing = 11,574 lbs.;
Max fuel = 2,000 lbs. (312 USG);
Oil Qty.= 22 Gallons / 100 litres Max. (13 Gallons minimum to 18 Gallons normal.)
Useful load with max fuel= 2,525 lbs. (3500 lbs with half fuel carried).
Compressed Air System: 8 litre (490 Cu.In.) Air Cylinder at 49 bars (711 PSI) maintained by engine driven AK-50M compressor and AD-50 relief valve. Pressure gauge is on pilot's left hand console. A pressure reducer supplies 10 bars (145 PSI) for the main brakes.
The Air Pressure is required for the pneumatic main wheel brakes, but can be used to charge the landing gear shock absorbing oleo-pneumatic struts when dry nitrogen is not available. A fitting is also available to fill the tires from this system. The 8 litre air cylinder can also be charged from appropriate ground support equipment.
Electrical System: 24v DC battery with engine driven generator to maintain charge.
Voltmeter and Ammeter on Instrument Panel. The 28v DC generator requires at least 900-1000 RPM to kick in. 36v 3 phase 400hz AC power, supplied by two converters, is used to power the Russian Gyroscopic compass, Artificial Horizon and ADF.
CO2 Fire Extinguishing System with automatic fire detector: Nine fire detectors are located throughout the engine compartment. If the Fire Warning Lamp light, the CO2 system can be activated by breaking the safety seal and pushing the button. The CO2 bottle has an electrically activated pyrotechnic cartridge to release the CO2 into the collector. Portable CO2 Fire Extinguishers are normally installed in the cockpit and cabin as well. Oil Cooling System: The Oil System consists of a 125 litre (33 gal) Max. Permitted
22 gal. tank, suction pump and an external Oil Cooler with electrically controlled shutters. Use Aeroshell 100 Oil.
The following data applies to all An-2s except float versions which have reduced performance and load capacities. Data is based on a typical weight of 11,600lbs.
Red Line Speed: V-NE 162 kts = 300 Kph
White Line Flaps: V-FE 70 kts = 130 Kph
Best Glide: 65 kts = 120 Kph
Maximum Speed: 139kts or 160mph or 257Kph (120kts / 220Kph more typical) Economy Cruise Speed: 100kts or 115mph or 185Km (95kts / 175Kph more typical)
Minimum Speed: 49kts or 56mph or 90Kph
Take-Off Speed: 43kts or 50mph or 79Kph (15 degrees of flap).
Landing Speed: 46kts or 53mph or 85Kph (30 degrees of flap).
Stall Speed: 35-40kts or 65Kph but controlled descents are possible at 25kts/30mph/46Kph
Typical SL Take-Off distance to clear 50 foot obstacle: 1600 feet.
Minimum SL Take-Off Run: 560 feet.
Typical SL Landing distance over 50 foot obstacle: 1400 feet.
Normal Range: 485nm with 45 min. reserve.
(550nm max with approx. 6 hours endurance).
Max SL Rate of Climb: 680 fpm, 30 minutes to 14,425 feet.
Ceiling: 14,425 feet with 1,100lbs. of cargo.
Note 1: Tolerable Cross wind component is only 8 kts with full flaps.
Note 2: Aircraft cannot be taxied with wind in excess of 20 kts.