Ilyushin Il-18 (1946)

Ilyushin Il-18
Type:	Four-engine passenger aircraft
Design country:	Soviet Union
Manufacturer:	Ilyushin
First flight:	August 17, 1946
Commissioning:	Flight tests ended in 1947
Number of pieces:	1

The Ilyushin Il-18 ( Russian Ильюшин Ил-18 ) from 1946 is a four-engine passenger aircraft made by the Soviet manufacturer Ilyushin . The type was equipped with a retractable landing gear , radial engines and a pressurized cabin . The low-wing aircraft had a conventional tail unit. The first flight took place on August 17, 1946.

development

The design of the machine is based on the Tupolev Tu-4 and is comparable to its civilian offshoot, the Tupolev Tu-70 . The flight tests, which lasted until July 30, 1947, showed satisfactory flight behavior. The project was discontinued anyway. The official reason given was that the turbo-charged engines of the type ASch-73TK were not available in time. The fact that the Tu-70 could be manufactured more cheaply due to the use of around 75 percent of the parts of the mass-produced Tu-4 was also cited. It is more likely, however, that aviation in what was then the USSR simply did not need such a large civil aircraft at the time. That's why only one machine was built.

Technical specifications

The Il-18 had a round fuselage cross-section with a diameter of 3.5 m. In contrast to the smaller Il-12 developed at the same time, however, it had a pressurized cabin with oval windows.

The wings were designed as trapezoidal wings with a geometric aspect ratio of 12, which is high for commercial aircraft, which caused a high wing loading (up to 3400 N / m²).

The Il-18 was equipped with an extensive de-icing system for use over long distances . The nose edges of the wings were heated with engine exhaust gases. There was chemical de-icing for the cockpit windows and the propeller blades. As an innovation, the nose edges of the tail unit were electrically de-iced. Four generators were required for this.

The main landing gear had four wheels and moved forward into the engine nacelles. The nose landing gear had twin tires and retracted to the rear. What was new at the time was that the landing gear flaps closed again after the landing gear was extended.

Originally, the Il-18 was to have four ATsch-71 diesel engines . Even before the construction, based on the experience of flight tests of the Il-12, it was decided to use gasoline radial engines of the ASch-73K type with TK-19 turbochargers .

Flight testing

The prototype was built until the summer of 1946. The first flight on August 17, 1946 was carried out by the test pilot Wladimir Konstantinowitsch Kokkinaki at Moscow's M. W. Frunze Airport . Since the turbo compressors were not yet available at this point in time, the flight altitude was still limited to 2000 m. During the flight tests it was shown that the Il-18 could climb safely with 42.5 t and a failed engine. With a flight mass of 36 t it was possible to fly without a descent. On August 3, 1947, it was presented to the public at the air parade in Tuschino .

After the decision not to mass-produce the Il-18, the prototype was used for various test programs until 1950. Among other things, it was used as a tow plane for the cargo glider Il-32 . The prototype received the aircraft registration number СССР-Л1789.

Technical specifications

Parameter	Data
crew	5-6
Passengers	66
length	29.86 m
span	41.10 m
Wing area	140 m²
Empty mass	28,490 kg
Max. Takeoff mass	42,500 kg
Top speed	588 km / h
Range	2800 km
Engines	4 × Schwezow ASch-73
power	1680 kW (2285 PS) each

literature

• Ulrich Unger: Ilyushin IL-18 . In: Peter Bork (Ed.): Fliegerkalender der DDR 1987 . Military Publishing House of the GDR , Berlin 1986, p. 207-214 .
• de Agostini (ed.): Aircraft - The new encyclopedia of aviation . Munich-Karlsfeld 1993.

Individual evidence

1. ^ Karl-Heinz Eyermann , Wolfgang Sellenthin: The air parades of the USSR. Central Board of the Society for German-Soviet Friendship, 1967. p. 36.