Ilyushin Il-12

Ilyushin Il-12
Aeroflot Il-12, Budapest 1956
Type:	Airliner
Design country:	Soviet Union
Manufacturer:	OKB-240 Ilyushin
First flight:	August 15, 1945
Commissioning:	1947
Production time:	1946-1958
Number of pieces:	663

The Ilyushin Il-12 ( Russian Ильюшин Ил-12 , NATO code name : Coach ) was a Soviet airliner with two piston engines . It was developed from 1943 as a replacement model for the Lissunow Li-2 . Contrary to the original plan, the Il-12 was not equipped with a pressurized cabin .

history

During the Second World War , from around 1943, the chief designer of the OKB-240, Sergei Ilyushin , was still looking for a more modern and more powerful successor to the Li-2, which was a licensed version of the US Douglas DC , without having received a government contract -3 was. The Il-12 was in part inspired by the Li-2, but had significant structural differences in landing gear, wings and tail unit, so that it was more of a completely new type of aircraft than a further development of the Li-2. The original project included a four-engine aircraft with a pressurized cabin for up to 29 passengers and modified M-88 - radial engines . In January 1944 it was confirmed by the government, but in the same month it was decided to use only two Tscharomsky ATsch-3 diesel engines, each with 1300 hp. To do this, the engine nacelles had to be redesigned and the plans revised as a whole. The pressurized cabin was omitted and the number of passengers was reduced to 27. In autumn 1944, the planning phase was completed and the construction of a prototype began, which made its first flight on August 15, 1945. During testing, the diesel engines proved to be immature and since it was not foreseeable whether and when they would be suitable for series production, Sergei Ilyushin decided to use the already proven ASch-82 this time , which also took up less space, which means that the rear one The area of ​​the engine nacelles could now serve to accommodate the main landing gear. The modified Il-12 flew on January 9, 1946 - according to other information already on January 7 - with Vladimir Kokkinaki for the first time. The tests showed vibrations, but these could be eliminated by using other propeller blades. After completion of the trials, from July 1 to September 16, 1946, the state acceptance and approval for a takeoff weight of 16,800 to a maximum of 17,500 kg followed. At the beginning of 1947, aptitude tests were carried out at Aeroflot , which did not reveal any problems, so that the following June regular service began. Previously, the Il-12 was presented to the public at the traditional air parade on May 1st in Moscow-Tushino . The Il-12 was the starting point for the development of the Il-14 , the planning of which began immediately after the end of the test.

A total of 663 aircraft of this type were built in the Moscow plant No. 30 "Znamia Truda".

construction

The Il-12 is designed as a low-wing aircraft in all-metal construction. The fuselage has a circular cross-section and is made in half-shell construction. The three-piece wing shell construction are zweiholmig run, have a trapezoidal shape , and just like the normal tail -supporting . The Clark YH profile was used for the center section of the wing and the Clark K-4 profile for the outer wings . There are hydraulically operated split flaps on the rear edges. All control surfaces have a metal structure with fabric covering. A false keel was added in front of the vertical stabilizer due to insufficient directional stability during the test flights . The aircraft has a nose wheel landing gear with twin tires on the main wheels. When parked, the aircraft is secured by a rear support. The Il-12 is driven by two Schwezow Asch-82FNW radial engines (2 × 1850 HP) with four-blade adjustable propellers AW-9E-91. In later modifications, de-icing systems were used for the propellers, windows, tail units and engines.

Versions

In addition to the normal version for 27 passengers, there were also variants for 18 and 32 passengers.
The transport version can be recognized by the double-leaf door on the left.
The version Il-12D had an armed turret on the fuselage.
The Il-12T version could carry 26 fully equipped soldiers or 30 parachutists. In the medical variant, 16 patients on stretchers and six seated patients could be transported.

commitment

From 1947 the machine was used in scheduled service by the Soviet airline Aeroflot . The Il-12 was intended for 27 passengers or with a correspondingly reduced range for up to 32 passengers and four crew members, but this number was limited to 21 passengers due to a lack of engine power and after a crash near Voronezh in 1949 to 18, but this was limited to 1954 Ilyushin's operation was reversed. Mainly the Il-12 was flown in the Soviet Union, among other things also in the polar air fleet of Aeroflot. It was also used in a few copies by the Czechoslovak airline ČSA (see photo), the Polish LOT , the Chinese CAAC , the Bulgarian TABSO and the Romanian TAROM .

Incidents

From the first flight in 1946 to the end of operations in 1970, the Ilyushin Il-12 caused 49 total aircraft losses. 486 people were killed in 45 of them. Examples:

This list is incomplete and has only just begun (August 2017).

• On April 30, 1953, one of the 23 inmates died while ditching an Il-12P on the Volga on the domestic scheduled flight Aeroflot Flight 35 from Moscow via Kazan to Novosibirsk.

• On November 24, 1956, an Il-12B of the Czechoslovak airline CSA ( aircraft registration OK-DBP ) crashed , probably due to engine problems, 13 kilometers after take-off from Zurich-Kloten Airport , only 500 m from the southern outskirts of Wasterkingen (Switzerland) an agricultural area. All 23 passengers and crew members died.

Technical specifications

Parameter	Data
crew	4-5
Passengers	18-32
length	21.30 m
span	31.70 m
height	8.07 m
Wing area	100.00 m²
Wing extension	9.3
Wing swept	2 °
V position	3 °
Undercarriage track width	8.00 m
wheelbase	5.37 m
Empty mass	9,000 kg
Payload	8,000 kg
payload	3,000 kg
Takeoff mass	17,000 kg
Wing loading	170.0 kg / m²
Power load	5.3 kg / hp
drive	two 14-cylinder ASch-82FNW radial engines with 1,361 kW (1,850 hp) each
Top speed	375 km / h at an altitude of 2,000 m
Cruising speed	economical 300 km / h maximum 320 km / h
Landing speed	145 km / h
Climb performance	5.0 m / s
Service ceiling	6,500 m
Range	normal 1,500 km maximum 1,900 km
Take-off / landing runway	500 m / 700 m

See also

• List of aircraft types

literature

• Ilyushin Il-12 and Il-14 . In: de Agostini (ed.): AIRCRAFT. The new encyclopedia of aviation . No. 83 . Topic, Munich-Karlsfeld 1994, p. 2297-2301 .
• Jefim Gordon , Dmitri Komissarow: Ilyushin: Il-12 and IL-14 - Successors to the Li-2 . Midland, Hinckley 2006, ISBN 1-85780-223-3 .

Web links

Commons : Ilyushin Il-12  - collection of pictures, videos and audio files

Individual evidence

1. ↑ Ulf Gerber: The great book of Soviet aviation 1920–1990. Development, production and use of the aircraft. Rockstuhl, Bad Langensalza 2019, ISBN 978-3-95966-403-5 , p. 490
2. ^ Rudolf Höfling: Ilyushin since 1933. Motorbuch, Stuttgart 2013, ISBN 978-3-613-03604-8 , p. 120
3. ↑ Rudolf courtier: Ijuschin. Since 1933. Motorbuch, Stuttgart 2013, ISBN 978-3-613-03604-8 , p. 46
4. ↑ Holger Lorenz: The German variant of the Soviet IL-14P. (Ed .: Luft- und Raumfahrttechnik Sachsen-Thüringen), Groer, Chemnitz 2019, ISBN 978-3-00-062500-8 , p. 6ff.
5. ↑ Accident statistics Ilyushin Il-12 , Aviation Safety Network (English), accessed on December 17, 2017.
6. ↑ Air-Britain Archive: Casualty Compendium (English) Part 69, June 1998 pp. 98/55.
7. ^ Accident report IL-12 OK-DBP , Aviation Safety Network (English), accessed on August 20, 2017.
8. ^ Heinz A. F. Schmidt: Soviet aircraft . Transpress , Berlin, p. 45 .