Tipos de fluido
Wikipedia contém um bom resumo dos diferentes tipos de fluido:
Types
Type I fluids have a low viscosity, and are considered "unthickened". They provide only short term protection because they quickly flow off surfaces after use. They are typically sprayed on hot (130–180°F, 55-80°C) at high pressure to remove snow, ice, and frost. Usually they are dyed orange to aid in identification and application.
Type II fluids are pseudoplastic, which means they contain a polymeric thickening agent to prevent their immediate flow off aircraft surfaces. Typically the fluid film will remain in place until the aircraft attains 100 knots or so (almost 200 km/h), at which point the viscosity breaks down due to shear stress. The high speeds required for viscosity breakdown means that this type of fluid is useful only for larger aircraft. The use of type II fluids is diminishing in favour of type IV. Type II fluids are generally light yellow in color.
Type III fluids can be thought of as a compromise between type I and type II fluids. They are intended for use on slower aircraft, with a rotation speed of less than 100 knots. Type III fluids are generally light yellow in color.
Type IV fluids meet the same AMS standards as type II fluids, but they provide a longer holdover time. They are typically dyed green to aid in the application of a consistent layer of fluid.
Chemical Composition
The main component of deicing fluid is usually propylene glycol or ethylene glycol. Other ingredients vary depending on the manufacturer, but the exact composition of a particular brand of fluid is generally held as confidential proprietary information.
Ligue com antecedência para o aeroporto para ver que tipo de fluido de gelo / anti-gelo eles têm, porque cada um é diferente.
Limites de tempo
Todos os anos, a FAA publica tabelas que incluem informações sobre quanto tempo os vários fluidos do deice fornecerão proteção sob várias condições climáticas. Aqui está uma tabela de exemplo:
Para este fluido específico (ABAX ECOWING AD-49 Tipo IV), podemos pesquisar um exemplo específico como:
- -10 graus Celcius
- 75% de fluido e 25% de água
- Light Snow
Isso mostra que o fluido fornecerá proteção para 1:40 a 2:05. Se você está atrasado mais do que isso, você precisará deitá-lo novamente. Uma vez que todas as partes da aeronave precisam ser protegidas, o tempo começa quando elas começam a pulverizar a aeronave. Note que outros tipos de fluidos (particularmente fluidos do Tipo I) têm muito tempos de permanência mais curtos do que isso, então tenha cuidado e certifique-se de verificar!