Pro-inflammatory cytokines: IL-1, IL-8, IL-10, IL-12

IL-12

(according to NATO:
Coach
- “intercity bus”) is a passenger (transport) aircraft for short and medium-haul airlines. The design is an all-metal twin-engine low-wing aircraft with a traditional layout with piston engines and a tricycle landing gear with a nose wheel. The first flight was carried out on August 15, 1945 under the command of test pilot Vladimir Kokkinaki. Il-12 replaced Li-2 and DC-3 on USSR airlines. Later, a more advanced IL-14 was created on its basis.

History of creation

In October 1943, the S.V. Ilyushin Design Bureau began work on the design of a passenger aircraft on its own initiative[4].

The first version of the Il-12 aircraft project was designed for 29 passengers housed in a pressurized fuselage. The maximum flight range was assumed to be 5000 km with a cruising speed of about 400 km/h. It was planned to install four M-88V engines on it (a modified version of the M-88B, which had proven themselves on the Il-4).

In its further development, the aircraft project underwent significant changes.

Four M-88V engines were replaced with two ACh-31 diesel engines, the number of passengers was reduced to 27, and it was decided to abandon the pressurized fuselage.

On March 2, 1944, the layout and general appearance of the Il-12 with ACh-31 engines were approved by S.V. Ilyushin.[5] By the fall of 1944, the preliminary design was completed, and construction of the prototype aircraft began.

The first flight of the Il-12 with ACh-31 diesel engines took place on August 15, 1945. Several flights of test pilots Vladimir and Konstantin Kokkinaki under the factory test program revealed the need for significant modifications to the experimental engines, which could seriously delay the release of the Il-12 on regular lines.

S.V. Ilyushin decided to replace the ACh-31 diesel engines with ASh-82FN gasoline engines. The design of the aircraft was modified to accommodate the installation of new engines, and on January 9, 1946, the first flight of the Il-12 with ASh-82FN engines took place. In the first flights, strong shaking of the propellers manifested itself, which arose due to insufficient rigidity of the blades. Flight tests were carried out on three versions of the propellers, and the shaking was eliminated.

State tests of the Il-12 were successfully completed from July 1 to September 16, 1946.

On August 18, 1946, the first public display of the aircraft took place at an air parade in Tushino.[6]

On October 21, 1946, the Ministry of Aviation Industry issued an order to launch the Il-12 into mass production at Moscow plant No. 30.[6]

Tests

In 1950, the Yak-12 UT was tested at the NIIVVS Group of Companies and was recommended for air force flight schools as an effective simulator for training flight personnel. The following disadvantages were identified:

• 1700 blade revolutions per minute indicated the weak power of the GSK-1500 wind generator.
• The antenna used had insufficient power - the receiver only worked at an altitude of no higher than 1850 meters.
• The range of the compass was 160 km. This was not enough, since the commission put forward requirements of at least 180 meters.

After testing in June, a repeat test was scheduled in October of the same year. After modifications, the Yak-12 UT was equipped with:

• the VD-5 wind engine, which was characterized by a change in the pitch of the blades during flight;
• The installed T-shaped antenna worked effectively at any height.

In 1952, this aircraft successfully passed new tests. But nevertheless, nowhere in the documents is it listed as the Yak-12 UT.

Exploitation

At the beginning of 1947, five Il-12 aircraft of the experimental series were transferred for operational testing to the first separate air group of the Civil Air Fleet, which was based at Vnukovo airport. During operational testing, 1,500 flights were performed. According to the pilots, the Il-12 was easy to control and could be piloted by both I and II class pilots[7]. Operational tests were completed on May 20.

On May 1, 1947, a group of Il-12s took part in an air parade over Red Square.

On June 1, 1947, regular passenger operation of the Il-12 began at Aeroflot[2].

In 1948, the Il-12 was launched on international scheduled flights. The first airline to use the Il-12 was Moscow - Sofia. Then Il-12s began to fly regularly to Berlin, Belgrade, Budapest, Bucharest, Warsaw, Vienna, Kabul, Prague, Tehran, Stockholm, Helsinki, and Ulaanbaatar. In 1954, the Moscow-Paris airline opened.

In the USSR, the longest flight of the Il-12 was Moscow - Khabarovsk, with a length of 7000 km. The flight took 28 hours, with five intermediate landings.

Since 1956, Il-12 aircraft began to be used in Antarctica.

From the second half of the 1950s, the new Il-14 gradually began to replace the Il-12. In the USSR, Il-12 aircraft were operated until 1968, when the crew of Major V.M. Bazilevich transported the last Il-12 from the 478th training aviation regiment in Borisoglebsk to the Cheboksary school of junior aviation specialists[2].

In China, IL-12s were used on passenger lines until 1988[8]. And two military vehicles with tail numbers “35240” and “35241” were used until October 1993, when they were installed in eternal parking at the Datan Shan Museum[3].

Advantages and disadvantages of IL-12

The IL-12 managed to quickly “conquer” the domestic passenger airlines of the Soviet Union, and then just as quickly “settle” on international airlines. The secret of its success was quite simple: this aircraft was the first fully passenger aircraft developed and produced in the USSR. The ease of operation of the Il-12 was also repeatedly noted, making it accessible to even less experienced pilots.

Thanks to the IL-12, a new era in the life of piston aircraft began. In particular, it was on its basis that the more advanced Il-14 was developed and put into mass production, which was operated an order of magnitude longer - right up to 1989.

As for the aircraft's shortcomings, the main one is the inability to carry out an extended takeoff. This meant that if one of the engines failed, the Il-12 had little chance of landing unscathed. It was this drawback that became the main headache of S.V. Ilyushin’s experimental design bureau during the development of the Il-14.

You can also point out a number of relatively minor design flaws of the machine. In particular, these are some aerodynamic shortcomings of the Il-12, as well as errors in the design of its landing gear doors.

Modifications

Special options

: Two IL-12s were used as flying laboratories: meteorological and testing experimental PIS (anti-icing systems). Several Il-12s were equipped for aerial photography and at least one was equipped for aerial electromagnetic surveying, used for geological mapping and mineral exploration.

Description

The 1947 Yak-12 is a strut-braced high-wing aircraft using the M-11FR engine. The aircraft design may have a two- or three-seat cabin. Initially, the Yak-12 was designed as a two-seater. The wing struts are V-shaped and converge at a point for attaching the landing gear. Due to the presence of a fixed duralumin slat, a significant angle of attack is not dangerous. Improved pyramidal chassis (tested on the Yak-10) contain a special guy band that stretches from each wheel to a rubber shock absorber.

The braking function is carried out by main wheels measuring 6 x 18 cm and tail wheels measuring 20 x 11 cm. Skis can be attached to them. The control contains cable wiring. Slats located on the wing significantly improve landing properties and have a positive effect on safety during flight.

Flight performance

Data source: Shavrov V.B., History of aircraft designs in the USSR 1938-1950, 1988.

Specifications

• Crew: 4-5 people
• Passenger capacity: 18-32 people
• Length: 21.31 m
• Wingspan: 31.7 m
• Height: 7.8 m
• Wing area: 103.0 m²
• Wing profile: Clark-YH
• Wing aspect ratio:
  9,75
• Average aerodynamic chord:
  3593 mm
• Chassis base:
  5.184 m
• Chassis track:
  7.92 m
• Empty weight: 11,000 kg
• Curb weight: 14,310 kg
• Normal take-off weight: 17,250 kg
• Full load weight:
  6118 kg
• Fuel mass in internal tanks: 2940 kg
• Fuel tank capacity:
  4170 l
• Powerplant: 2 × radial ASh-82FN
• Engine power: 2 × 1850 l. With. (2 × 1380 kW)

Flight characteristics

• Maximum speed: at an altitude of 2000 m:
  407 km/h
• at the ground:
  366 km/h

Comparative table of characteristics of experimental and production models

Data source:

From the history of Soviet aviation: Aircraft of the S.V. Ilyushin Design Bureau /
G.V. Novozhilov, D.V. Leshchiner, V.M. Sheinin, etc.;
edited by Novozhilova G.V. - M.: Mechanical Engineering, 1990. - P. 374-375. — ISBN 5-217-01056-8

The fate of TU-70

There were several reasons for this, and the most important was the heavy workload of factories producing aircraft with the production of military aircraft for the Air Force. Aeroflot then used the Il-12 for 27 seats, the LI-2 for 28 passengers, and it was believed that this was enough. Although they had a short flight range, they had to be used both on long routes and on routes with popular destinations. For example, at a cruising speed of 350 km/h, a 700 km flight along the Moscow-Leningrad route in 1949 lasted 3 hours.

Such flights were carried out on the Li-2, but longer flights were made with the help of the Il-12, carrying 18 passengers each. The flight Moscow - Vladivostok (6800 km) was carried out with nine landings to refuel the aircraft, and this took more than 32 hours.

However, it was considered that Aeroflot’s needs were fully satisfied by the Il-12 and Li-2, and domestic airlines at that time did not need such a large aircraft. There was also another reason that did not allow the use of the TU-70: the technical backwardness of the airfields. A new aircraft requires a concrete runway, and at that time there were very few airports that had them. The issue of modernizing airfields was not yet on the government’s agenda at that time. The TU-70 aircraft was simply ahead of its time.

The Tu-70 was not written off at that time, but was transferred to the Air Force and was used for official civil air transportation of passengers. Sometimes it was used by Air Marshal V. Stalin. After his father's death, he resigned, and the TU-70 was decommissioned in 1954.

The T-75 aircraft had a similar fate; it was a military transport vehicle, which was considered inappropriate for the Airborne Forces at that time. However, the beginning of work on building machines with a long flight range, with turbojet and turboprop engines was laid, and it was not in vain for the Soviet aircraft industry.

https://youtube.com/watch?v=lMKnxnL1HsQ

Disasters

37 Il-12 aircraft were lost in accidents and plane crashes [ source not specified 2466 days

].

Manufacturing parts for the product

Based on the existing drawings, you can begin cutting out the required parts. It's good if the part has a large number of straight lines. In this case, it is considered simple.

To work with such a drawing you will need a needle. Using it, all available angles are marked with punctures. Then, along a ruler placed from one puncture to another, paper cuts are made using a stationery knife. They are carried out sequentially until the drawing produces a part of the future aircraft that is completely ready for gluing.

When gluing them, it is important to ensure that the dimensions and geometry of the future model are not violated

On each sheet there may be excess areas that need to be cut off. As a result, all fragments of the structure must fit perfectly together. Only after this can they be glued using a syringe.

Notes

1. Official website of JSC Aviation Complex named after. S.V. Ilyushin." Dates of first flights. Archived copy from June 28, 2013 on the Wayback Machine
2. ↑ 1 2 3 Talikov N.D.
   Three quarters of a century of “Ilyushin’s” sky... - M.: Bulletin of the Air Fleet, 2008. - P. 116
3. ↑ 1 2 Udalov K. G., Maraev R. V.
   Ilyushin’s first-born passenger // Aviation and time. - 2000. - No. 5. - P. 16
4. Talikov N.D.
   Three quarters of a century of “Ilyushin’s” sky... - M.: Bulletin of the Air Fleet, 2008. - P. 97
5. Talikov N.D.
   Three quarters of a century of “Ilyushin’s” sky... - M.: Bulletin of the Air Fleet, 2008. - P. 98
6. ↑ 1 2 Talikov N.D.
   Three quarters of a century of “Ilyushin’s” sky... - M.: Bulletin of the Air Fleet, 2008. - P. 115
7. Ed. board: Kutepov A. Ya., Makarevsky A. I., Minaev A. V., Novozhilov G. V. and others. Scientist and designer S. V. Ilyushin. - M.: Nauka, 1978. - P. 79
8. Egorov Yu. A.
   Aircraft from the S. V. Ilyushin Design Bureau. - M.: RUSAVIA, 2003. - P. 217
9. Talikov N.D.
   Three quarters of a century of “Ilyushin’s” sky... - M.: Bulletin of the Air Fleet, 2008. - P. 120
10. Talikov N.D.
    Three quarters of a century of “Ilyushin’s” sky... - M.: Bulletin of the Air Fleet, 2008. - P. 117
11. The Search Engine that Does at InfoWeb.net
12. Execution over Hua Gou, November 25, 2015 Natalya Sergeeva. Internet portal "Rossiyskaya Gazeta - Russian Weapons"
13. Review of the IL-12 model from Amodel