Antonow An-26 1972. - History
232b Section 1972-09-13
See Antonov An-24.
In 1968, another design of the widely used An-24 transport aircraft was developed at the design office of Father K. Antonov. The aircraft was designated An-24 TW. The aircraft combined several solutions used in previous constructions. The changes were large enough that the aircraft received the new An-26 designation. At the same time, the plane wanted to be presented best abroad, so a new name was necessary.
The main innovation was the use of rear loading through a large gate closed by gates. When opening, the element is lowered down and then forms a gangway followed by loading. In addition, this element can be moved under the hull to allow e.g. direct unloading from the truck. These doors are opened both at standstill and during flight. The door allows passage of objects 2.1 m wide and 1.5 m high.
The aircraft hold is large. Equipped with a floor conveyor with a load capacity of 4,000 - 4,550 kg and a ceiling crane with a load capacity of 1 500 kg. The main element of the crane is a ŁPG-250 / 500T or BŁ-56 winch with a load capacity of 1 500 kg. It moves along the rail placed in the ceiling. The floor transporter has, among other things, the task of ejecting the load from the hold during a flight that will fall on a parachute. Loads are automatically dropped using the PGS-24 device. It can be programmed into cycles and groups. Loads dropped from the air (during a flight) can be dropped aiming at the drop area. The NKPB-7 sight is located in the navigator's cabin in a semicircular fairing of organic glass. Just the navigator can make this dump.
However, the basic function of the transporter is loading and unloading at the airport. The working element are chains hidden in the floor, which do not protrude. Suitable locks are attached to the slots. The chain is set in motion by electric motors that use power from the on-board electrical installation. A passenger car the size of the Volga or Mercedes or an off-road UAZ-469B (typical military vehicle 70/80 years) can board.
The hermetic cockpit and hold allow passengers to be transported at heights of up to 6,000 m without the need for oxygen equipment.
In addition to transporting cargo, the aircraft is adapted to landing skydivers. There are seating places for 41 people along the cargo hold sides. The last spot, on the right, is for the landing commander. The seats are easily folded. Under the ceiling there are two lines for forced opening of parachutes and a system for folding hanging release lines and a safety railing. They increase the safety of conducted exercises.
The aircraft can easily be adapted to evacuate patients. The hold can accommodate 24 people with stretchers and two medical staff.
The shape of the rear fuselage is aerodynamically unfavorable and increases the resistance of the aircraft. Exactly there are two unfavorable vortices. To partially eliminate this phenomenon, two fins were placed. The covering was made of laminate, filled with glass fiber and stiffened with foam.
New technologies were used in the aircraft production process. Among other things, welding and gluing. Eg the side members are spot welded to sheet metal. Then glue is applied, which capillary penetrates into the gaps between the stringers and plates. Heat treatment hardens the adhesive. Then the element undergoes X-ray inspection. Then anticorrosive coatings are applied. Elements prepared in this way are mounted to the skeleton. To reduce the weight of the structure, the fuselage plates and tailings are chemically etched.
The airframe was mainly made of large-size panels. The production uses mainly aluminum alloys and high-strength steel. Non-metals were also used; Volocite, powder molding, polarized organic glass, foam materials, polyamide resins, Teflon and polyurethane.
The propulsion system of the An-26 aircraft is a sensation on a global scale. It consists of three engines. Two main turboprop and one turbojet RU-19 A-300 with 1 x 8.80 kN (1 x 900 kG). This turbojet engine acts as a starter for main engines, supports start, and can also be a marching engine. The RU-19 A-300 engine is a typical APU and driving motor. Starting engines is independent of airport sources. In reality, however, the engine is started using airport power sources. During start, a failure of one of the engines does not interrupt its continuation. Main engines are AI-24 T with 2 x 2 103 kW.
The prototype of the aircraft was flown in 1969, and because it was decided to show it at the Paris Salon this year, it was given the new designation An-26 and board number CCCP-261. During this salon, the aircraft was described as one of the most interesting constructions. When returning from Paris, the plane had a stop at Okęcie. The first presentation of the Antonov An-26 aircraft in Poland took place then.
In 1969, serial production of the Antonov An-26 aircraft was launched. About 1,000 were built. In 1981, an improved version was flown, designated An-26 B. The aircraft has good flight characteristics. With a load of 2,100 kg it has a range of 2,550 km. Antonov An-26 aircraft has several more varieties. Versions are noteworthy; aerophotography An-30 with a glass bow. First flight in 1974. It has a glazed nose, in which the position of an officer-camera operator was placed. The cockpit was also rebuilt. It was placed higher to improve visibility. The aircraft has automatic and semi-automatic cameras on board. Some cameras are gyroscopically stabilized. On board, you can process movies and photos on an ongoing basis.
The drive unit consists of 2 x 2,003 kW AI-24 NT engines and a RU-19 A-300 turbojet engine with 1 x 8.83 kN thrust.
The second plane is An-32, or An-26 with much more powerful engines. The An-32 aircraft in 1977 was first shown at the Paris Air Show. AI-20 M engines with 2 x 3 862 kW. Thanks to these engines, the aircraft is able to operate from airports located at altitudes of 4,000 - 4,500 m above sea level and at an air temperature of up to + 25 degrees C. An-32 version adapted to Western standards was offered to Polish Military Aviation.
Antonow An-26 in Poland. 1972.
The An-26 aircraft belongs to the class of small transport aircraft, however in Polish conditions we treat it as a medium-sized aircraft.
In 1972, An-26 aircraft were introduced into the aviation equipment of the Polish Army. The main task of the An-26 aircraft was to secure the landing of soldiers of the 6th Pomeranian Airborne Division. They replaced the outdated Iliuszyn Ił-14 aircraft. In total, 12 pieces of Antonov An-26 were purchased.
The first three planes with the numbers 1308, 1309, 1310 were delivered to Poland on September 13, 1972. The next two nb 1402, 1403 were delivered on November 4, 1972, and a week later, on November 11, 1972, another two nb 1406, 1407. The remaining five machines were delivered the following year, on March 20, 1973.
Initially, Polish An-26 aircraft were painted according to the following pattern; in the middle of the fuselage at the height of the windows a navy blue belt, upper part is white, lower part is gray. Quickly reach, the planes were repainted in a gray uniform color.
The first public show of Polish An-26 aircraft took place on November 16, 1973, when a group of soldiers from 6 PDPD flew to Cairo, Egypt.
From autumn 1974, Polish An-26 aircraft were included in the transport of mail as part of the Post-LOT system. Planes carried mail from distant provinces to Warsaw and back at night. An-26 night flights have significantly improved the transport of letters and parcels throughout the country.
Along with Poland's accession to NATO, major repairs of almost all machines were carried out, enabling their operation for another 10-15 years, until about 2010-2015. The aircraft received new equipment with means of communication and navigation, as well as new multi-colored painting (camouflage). This camouflage means that these planes are eagerly photographed at Polish and foreign airports.
An-26 aircraft proved to be good machines and even the purchase of 10 modern CASA C-295 M did not cause their mass withdrawal. The huge demand for transport flights dictated by the changed war doctrine, causes the need to increase the transport capacity of Polish Military Aviation. However, since 2005, the slow process of decommissioning An-26 aircraft has begun. The last flights were made at the beginning of 2009.
An-26 aircraft belong to machines in the Polish Army that have not suffered any major disasters.
Written by Karol Placha Hetman