The Soviet school of aircraft engineering at one time in practice repeatedly proved with its developments that it really was one of the best in the whole world. For several decades, a great many aircraft for various purposes were created in the USSR. Among all this diversity, the IL-18 aircraft is especially worth noting. We will tell you about this real miracle of domestic engineering in the article as much as possible.
Introduction
After the end of World War II, the number of military aircraft significantly exceeded the number of civilian vessels. In this regard, the question of providing the aircraft fleet with new machines that could significantly increase the number of passenger traffic by air, the demand for which after the end of hostilities grew day by day, was very acute on the agenda.
Even then, it was clear that in the face of an ever-increasing need for air travel, aircraft equipped with piston engines could no longer fully satisfy all the requirements. And therefore, a task arose for the leadership of the USSR, the solution of which was ultimately entrusted to the respected design bureau of Ilyushin.
Brief historical background
In the spring of 1945, the legendary design engineer S.V. Ilyushin began to actively develop the project, on the basis of which the Il-18 aircraft was subsequently created. The developer planned to install on this machine four of the most powerful aircraft engines ACh-72, created by A.D. Charomsky.
In 1956, the Council of Ministers of the USSR issued a decree that provided for the creation of a turboprop aircraft. The development of the machine proceeded very quickly, and the prototype took to the air after a fairly short period of time. In 1957, the IL-18 aircraft model was presented to the then party top of the Soviet Union and members of the government. The ship was really liked by the USSR Secretary General Nikita Khrushchev, and the machine itself was given its own name "Moscow". It was such a nickname that the first secretary of the Moscow Committee of the CPSU, Furtseva E.A.
Destination
The IL-18 airplane, the photo of which is given in the article, according to the idea of its legendary creators, should be able to provide comfortable transportation of passengers in the amount of 60-65 people over a distance of 5000 kilometers. At the same time, the cruising speed of the aircraft was planned within 450 kilometers per hour, and the flight altitude was calculated in the range of 7500 meters.
It was planned that the small fleet of IL-18 will operate without additional landings along the longest routes both within the USSR and outside the state. In particular, Moscow - the republics of Central Asia, Moscow - the Caucasus, Moscow - the Far East, Moscow - the industrial part of the Urals. At that time, the main movement of passengers, cargo and mail was carried out in these directions. In addition, such a serious, one might even say, absolutely comprehensive approach to creating an air fleet of civil aviation in practice in the Soviet Union was carried out for the first time in its entire long history.
Description
The appearance and many design solutions of the newly created IL-18 were largely borrowed from the model of the four-engine high-altitude aircraft Il-12. However, the latest development of Ilyushin at the same time received much larger linear dimensions and its own weight.
As for the aerodynamic layout of the wing, it was able to ensure the perfect perfection of aerodynamics and, as a result, the high level of safety of the IL-18. The design bureau decided to obtain very high aerodynamic performance and cruising flight speed, and therefore the wing was used on the plane with an extremely large geometric elongation, which was 12.
A very impressive specific wing load of 310-340 kilograms per square meter was also provided. Such an approach literally required engineers to solve several very complex engineering problems in the process of its creation, aimed at achieving the required strength and stiffness at the lowest possible weight costs while ensuring optimal flutter critical speed.
The structural subtleties of the wing mechanism of the aircraft and the presence of Fowler slotted flaps, as well as well thought-out landing gear parameters made it possible to operate the vessel on unpaved and concrete runways, the length of which was less than 1000 meters. From a practical point of view, this greatly expanded the scope of operation of the aircraft, because not every machine of this kind could take off or land on such short runways.
Fuselage
Passengers and crew of IL-18 (the USSR is the country of manufacture of this aircraft) were in a completely sealed fuselage, which was necessarily equipped with a ventilation system with air intake for delivery to the cabin from turbocharged compressors of power engines.
Initially, several options for the layout of the fuselage were developed, but in the end, a drawing with a round cross section, the diameter of which was 3.5 meters, was selected. Such a fuselage had the smallest possible mass multiplied by good stiffness and strength. The configuration of the main part of the aircraft made it possible to locate baggage and cargo rooms below, directly under the floor of the passenger part.
It is worth noting the particular pedantry of Ilyushin, who paid close attention to the design of the fuselage. For example, an engineer revealed that the oval-shaped windows used earlier did not work very well in practice. It was clear that cracks and deformations appeared at high altitudes along the edges of such windows, eventually leading to the final depressurization of the entire fuselage. In this regard, the IL-18 received round windows, and the fuselage itself allowed the cockpit, radio operator, on-board mechanic, passenger compartment, toilet, sideboard and wardrobe. The project initially included the installation of 66 seats for people flying in the first class.
Options
In addition to the main option, an aircraft was designed for 40 highly comfortable seats. A night option was also designed, where 28 beds were installed. Moreover, the IL-18, whose characteristics were advanced at the time, could also be used as a landing ship capable of carrying 90 soldiers on board. The cargo version of the aircraft allowed transporting 8 tons of cargo of various sizes.
The first major design changes
In the summer of 1945, the first Il-18, whose engines were originally ACH-72, received new power plants of the ASh-73TK air-cooled gasoline type and TK-19 turbocompressors. The take-off power of these engines was 2400 horsepower. Each of them rotated the air four-blade screws AB-46NM-95. But in the end, they were abandoned, and in the mid-50s they designed a completely new aircraft.
Security level
The IL-18, the photo of which is in the article, was equipped with equipment that allowed the vessel to be operated day and night, even in extremely difficult weather conditions, in which many other aircraft would not even try to fly into the air.
Optimum flight safety was guaranteed by a whole complex of various radio navigation aids, as well as the use of special protection against icing of the cockpit lantern, glass, propeller blades, keel, stabilizer and wing edges. The electric heating system consisted of the use of thoughtful sections of conductive rubber, which heated the required structural elements of the aircraft through the use of four fairly powerful generators mounted directly on the engines.
First flight
On August 17, 1946, the IL-18 first flew into the air, led by the most experienced test pilot Kokkinaki. As a result of this event, the aircraft received extremely positive reviews. During operation, it was revealed that the take-off of the machine is very simple, airborne take-off and take-off took place as usual. During climb, the ship showed steadiness and stability. Planning in the air went quietly, and the landing did not cause difficulties.
Very appreciated the comfort of the aircraft and passengers. The noise during the operation of the engines did not cause discomfort, and people could well communicate with each other in the cabin without raising their voices and hearing each other well, which was rare for flights of the time. The heating system in the winter period provided the most optimal temperature indicators.
Test Continuation
In August 1947, the IL-18 took to the sky at the head of a column of other aircraft in Tushino near Moscow and was demonstrated during the parade. After that, the ship was repeatedly operated in many more programs. In 1948-1949, the car was equipped with a special device for towing a heavy IL-32 glider. Over time, instead of piston engines, the IL-18 received AI-20 turboprops.
Final commissioning
In 1959, after passing all the mandatory state inspections, the aircraft began to make numerous flights within the Soviet Union. The machine was extremely unpretentious in maintenance, reliable and therefore for a long time remained in demand in the country, until the 1970s.
The ship's good performance allowed it to be sold to most countries of the socialist camp and other friendly powers, where it was positively received by both local experts and ordinary passengers. But nothing ever lasts in the world of technology, and already in the mid-1970s, the scale of production of the Il-18 began to decrease significantly, since it had serious competitors in the form of the Il-62 and Tu-154. These aircraft have already begun, in turn, to use jet engines rather than turboprops. In addition, the obsolescence of the aircraft began to affect.
main parameters
IL-18, the technical characteristics of which allowed him to be among the leaders for a long time, is still in operation in some countries of the world to this day. Among its main indicators are:
- Machine length - 35900 mm.
- Height - 10200 mm.
- Weight (empty) - 33760 kg.
- Wingspan - 37400 mm.
- The area of each of the wings is 140 square meters. m
- Speed (cruising) - 625 km / h.
- The maximum possible speed is 685 km / h.
- The flight ceiling is 10,000 meters.
- Power plants - 4 x AI-20.
- The maximum possible number of passenger seats can reach 120 people.
- The maximum allowable take-off weight is 64,000 kg.
- The capacity of the fuel tanks is 23,700 liters.
- The length of the run - 1000 m.
- The length of the passenger compartment is 24 m.
- Cabin width - 3.2 m.
- Cabin height - 2 m.
Modifications
For the entire period of production of the IL-18, a number of its variants were designed and put into operation, including:
- A - the first production model with NK-4 engines.
- "Salon" - a car specially designed for officials of the highest rank of the country.
- "Strip" - a vessel equipped with equipment for a fully automated flight, landing and take-off.
- IL-18V is an aircraft with three passenger cabins.
- D - equipped with fuel tanks with increased capacity. Used to fly to the North Pole.
- IL-18Gr - cargo version of the aircraft.
- "Pomor" - a machine designed to perform fish exploration.
- "Cyclone" - a vessel for conducting meteorological research and reconnaissance.
- IL-18E is an aircraft with a superior cabin that can accommodate 110 people.
- LL is a fully autonomous flying research laboratory.
- IL-18RT is a vessel used to collect and register telemetric information.
- T - transport and sanitary option.
- IL-18TD - landing transport aircraft used for military purposes.
Conclusion
At the end of the article, we can confidently say that the IL-18 is the first medium-range passenger airliner of the Soviet Union, which served for several decades. Over the years of its operation, practically no serious damage happened to him, but the century of jet engines managed to deprive him of his palm in the issue of air transportation of passengers and cargo.
However, there were also tragic moments in the history of IL-18 flights. So, in December 2016, near the settlement of Tiksi, the plane of the Russian Aerospace Forces crashed, as a result of which 32 military personnel were injured on board. The cause of the accident was the failure of the fuel supply system, although the version and crew errors and bad weather conditions were considered.