One of the meteorological phenomena that can affect an aircraft is the icing. It is the ice deposit on the aircraft and is produced when sub-melted liquid water freezes when it impacts with it.
In this article we are going to tell you all the characteristics, origin and importance of icing.
What is icing
We are talking about a meteorological effect that takes place in the upper part of the atmosphere and that can affect the aircraft when it passes through these areas. In this phenomenon, the ice mainly adheres to the elements that are exposed to the wind. All the elements that protrude from the plane can be altered due to icing.
Let's see what are the main alterations that can cause icing in the parts that protrude from the aircraft cell:
- Reduced visibility. If ice adheres to certain parts, the aircraft can cause reduced visibility at short and medium distances.
- Alterations of aerodynamic properties: When the means of transport is air, the aerodynamic properties are essential for efficient use of fuel. Ice can create instability in the aircraft's aerodynamics.
- Weight gain: the aircraft may experience an increase in weight depending on the ice remaining due to the surface.
- Power loss: it is a direct consequence of weight gain. As the weight increases, the aircraft loses power little by little.
- Vibrations: These delays on a continuous basis can cause structural fatigue in all the elements of the aircraft.
We know that icing on an airplane can occur in clouds, mist or fog. It all depends on the environmental conditions that are found at that time. It can also occur in the bosom of a precipitation. In this case, it is called freezing rain.
Protection against icing
The first thing to know to protect yourself from icing is to know those areas where it tends to occur more frequently. It is not advisable to fly in areas where meteorological conditions are favorable for icing formation. One way to protect against this phenomenon is to have de-icing equipment that helps remove whatever accumulates. However, this protection measure is more expensive since it must be incorporated into the aircraft.
There are antifreeze equipment to avoid the formation of the same and do not let it adhere to the surface. These systems can be of several types:
- Coated Mechanics: They are those that have a matic coating that, when inflated with air in the engine, breaks the ice. They are often used in algae and the tail of the tail.
- Thermal: They are those electric heaters that can be used in the Pitot tube. They are also air heaters that can be used on the leading edge of the water, on the propellers, on the carburetor and on the tail tail.
- Chemicals: These are various baths that are made with substances that help keep the subcooled water in a liquid state. The most normal thing is that the windshield glass is used frequently on the propellers.
Triggers
Let's analyze what the icing triggers are. First of all, a liquid water content is required, at a very low ambient temperature (the most normal thing is that it is below zero) and a surface temperature of the aircraft also below zero. Large drops may exist so inside the clouds with temperatures of -2 and -15 degrees and small droplets found at temperatures of -15 and -40 degrees.
Some of the favorable environmental conditions for the generation of icing are convergence at low levels and atmospheric instability. During atmospheric instability, strong rises of masses of hot water are very frequent, which, when they collide with a mass of cold water, generate vertically developing clouds. The pockets of cold air in height favor vertical movements and the development of clouds and greater instability.
The passage of frontal systems with high-speed winds also often causes icing. Depending on the area through which the aircraft passes, this effect is more or less likely to occur. For example, mountainous terrain often favors air rises and contributes to an increase in the amount of water droplets that form clouds. This increases the probability of icing. The effect of the coasts is quite similar to the orographic effect. The humid air that comes from the sea reaches a level of condensation when its rise increases. Once the height increases, a higher content of liquid water is generated in the clouds and the probability of icing increases.
Basic shapes
Let's analyze what are the basic forms of icing that exist:
- Granulated ice: It is a white, opaque, porous ice that comes off quite easily. They are usually formed at temperatures between -15 and -40 degrees mainly from small droplets. The process of forming this type of granulated ice is done quite quickly.
- Transparent ice: it is a type of ice that is clear, transparent, smooth and that it comes off with greater difficulty. It is usually formed at temperatures between -2 and -15 degrees and is mostly formed from large droplets. The freezing process of this type of ice is quite slow. And the fact is that the drops can flow a little before being frozen. In this way, the freezing surface increases. The flow of the current around the wing of the aircraft can be disturbed to a greater extent than the previous type of ice.
- Freezing rain: it is one of the most dangerous that exists. It is a very dangerous icing on the aircraft. And is that the ice is transparent and the precipitation intact uniformly on the plane. A thermal profile in height that has an inversion in the average levels is quite favorable to the formation of freezing rain.
I hope that with this information you can learn more about icing and its characteristics.