An innovative feature on the Il-114 is its de-icing system, which is based not on the traditional hot-air method, but on a pulse-wave technology which causes the ice to lose its grip on the airframe and fall away.

The system, now patented in 14 countries with others pending, was developed by an Ilyushin team led by Dr Igor Levin in the 1960s. Levin calculated that up to 25% of the power needed to keep an Ilyushin Il-18 or Il-62 functional was being used to provide hot air for de-icing. In 1961 he began to develop a way to break ice on thin-walled surfaces, so that air flow will remove it from the aerofoil.

An Il-18 was used for the first tests. The new system weighed in at 1t, and yet the energy required to de-ice the aircraft fell to around one-six-hundredth of that needed before. On the Il-18 the tests were conducted at altitudes from 3,250 - 24,000ft in outside air temperatures (OAT) of - 6¹C to - 50¹C and with icing intensities of 0.3 to 2.3mm per minute.

The system was found to work efficiently, and with none of the interference with electronic systems that were, and can still be, evident on other de-icers. The new system was found to be increasingly effective as ice thicknesses built up. Its production was recommended and it was installed on the production Il-38 maritime-patrol aircraft. Later tests on an early Ilyushin 11-76 led to the second-generation system being installed on all production Ilyushin Il-86s - an aircraft with an exceptional safety record.

The development of new materials and microchips, which includes the fixed elements plus the cables, has resulted in a third-generation system for the Il-114, which weighs in at just 16kg. The system now consists of light patches which are fixed to the leading edges at points proved in tests to be ice gathering. It is electrically activated, requiring just 200W power. The system is linked to the aircraft's flight-data recorders and has thus been fully analysed during the Il-114 test programme down to temperatures of -44¹C and, in older service aircraft, down to -58¹C. These tests have been scrutinised by the NII VVS (the Russian Air Force's research body) and by the GosNII GA (Russia's civil aviation research institute).

With 18 years operational experience on the Il-86, and over 25 years on the Il-38, the "new" system has a good track record. Dr Levin has now set up his own company, Impulse, to design, develop and market the new system.

Source: Flight International