Deicing fluid

De-icing fluid (LI) - A liquid for ground de - icing of aircraft (AC) before flight. It is a solution of glycol (monoethylene glycol, diethylene glycol or propylene glycol) in water with various additives to improve performance (thickeners, dyes, etc.). Due to the presence of glycol, it has a freezing point much lower than that of water (up to −60 ° C according to GOST 18995.5-73, up to −40 ° C according to ASTM 1177-94). It is used to melt frozen precipitation (when heated to +60 .. + 70 ° C) and to protect against the accumulation of precipitation on the aircraft surfaces (in cold form).

Depending on the presence or absence of a thickener, its concentration and chemical nature, the fatty acids are divided into type I, II, III and IV. Type I (first) liquids are intended for use in a heated form, mainly for removing snow and ice deposits from aircraft surfaces and for short-term aircraft protection. Type II, III, and IV fluids are used for long-term protection. Due to the presence of a thickener in their composition, they have a higher viscosity and form a film on the surface that takes up precipitation and prevents them from freezing to the surface of the aircraft. When applied to prevent ground icing, these types of coolant are used cold, that is, at ambient temperature.

The fluids must comply with international standards SAE AMS 1424 and ISO 11075: 2007 (for type I fluids), SAE AMS 1428 and ISO 11078: 2007 (for type II, III, IV fluids). Testing of all liquids produced in the world for compliance with these standards is carried out in the AMIL laboratory (Canada) , and it also publishes lists of all types of fluid safety standards that meet these standards. These lists are used to compile yearbooks of permitted liquids by the aviation authorities of all countries of the world. The most authoritative Holdover Time (HOT) yearbooks are published by Transport Canada and the Federal Aviation Administration (FAA USA) . All RLP used in Russia are additionally tested for compliance with GOST R 54264-2010 (inspection body - State Research Institute of Civil Aviation ), the Federal Agency for Air Transport (Rosaviation) issues an annual list of permitted RLP.

De-icing fluids are available under the trademarks Killfrost, Safewing, Arctic DG, Octaflo, Defrost, etc.

Ground treatment of the aircraft’s outer surfaces with anti-icing liquid is an integral part of the implementation of the “clean” aircraft concept, according to which it is forbidden to start a flight if frost, wet snow or ice are on the surfaces of the wings, fuselage, controls, plumage, propellers, windshield, power installation or on air pressure receivers of barometric instruments of the aircraft. Refusal of de-icing treatment in the presence of snow-ice deposits on the outer surfaces of the aircraft is a gross violation of Russian and international aviation rules and may result in catastrophe with human casualties, as in the case of the crash of ATR 72 near Tyumen on April 2, 2012 ^[1] .

Note All military aircraft manufactured in the USSR and the Russian Federation do not require the use of life support systems, and the staffing table for the airfield support service simply does not provide special machines for processing life support systems. The preparation of the aircraft for the flight is entirely entrusted to the ground crew, including the mechanical removal of snow and ice.