Aircraft icing is a common and major hazard to the aviation industry. Depending on conditions, icing may have very little or major impact to aircraft performance. The types of icing that form on and affect aircraft, the variables in how each type of icing is formed and the categories of severity will be discussed. Numerous methods of prevention and treatment exist and all pilots should be well versed in flight rules and regulations concerning avoidance and response to icing situations.
Aircraft icing is nothing but trouble and a significant hazard to the aviation community. With the right upper level conditions, our winter season allows icing to occur when least expected and most pilots know very little about where icing will actually occur. With a small bit of meteorology related education, most can learn where ice may be waiting for them and how it can be avoided. Key items of merit would be where fronts were, where they were moving, the location of cloud tops/bases and what alternate routes are available. When flying, one should also be aware of several key locations in the United States: around mountains, the Great Lakes or other large bodies of water. And, if you don’t need to fly through a cloud, don’t do it. Although hazardous to all aircraft, each craft is either approved or not approved by the Federal Aviation Administration (FAA) for icy flight conditions. It is primarily the smaller and lighter aircraft that are not equipped with extensive forms of anti-icing protection and these are the ones most affected and legally banned from flight into known icing conditions (Landsberg, 2008).
Icing is normally encountered in when the temperatures range between 14 to 32 degrees Fahrenheit and liquid water is present in the atmosphere. There are basically two types of ice that adhere to airframe structures. They are known as rime and clear ice, and a mixture of the two is not uncommon. For rime ice to form, an aircraft needs to fly through an area of tiny super-cooled liquid drops. This super-cooled liquid is actually suspended in the cloud cover at temperatures already below freezing. Once the aircraft surface plows through this moisture, the drops are disrupted immediately adhere to and freeze before spreading out over the entire surface. This forms a rough and cloudy-white layer of ice known as rime. Even though the rime surface is rough and creates...