9.2 Weather Hazards

9.2 Weather Hazards

There are many weather hazard that cause great risk to aircraft. One that I believe is a great risk, is flying in icing conditions. I find this to be a great threat because it can sneak up on you and you may not even realize your leading edges are accumulating ice. It will change a smooth airflow surface and increase drag. In turn, it will decrease lift and add additional weight. (Landsberg, 2008)

Along with adding additional weight and drag to an aircraft, when icing occurs on an aircraft, especially on an aircraft that do not have an operational anti-icing or deicing system, it can block air inlets that are a part of the pitot and static systems. In turn it can cause erroneous indications on the instruments which could also be catastrophic. (Skybrary, 2019)

Water typically freezes at zero degrees Celsius. However in the atmosphere it will sometimes still exist in liquid form, even well below zero degrees. This is called a “super-cooled” liquid. As an aircraft gains altitude and flies through the air, the structure of the aircraft cools, making the aircraft structure at or below zero degrees as well. As the “super-cooled” liquid hits the aircraft, it immediately will turned to ice. (Skybrary, 2019) There are 3 types of icing. Rime Ice, which is when small “super cooled" droplets freeze rapidly when they contact the aircraft freezing surface. Clear Ice, which is when larger “super cooled” droplets hit the subzero surface, but only a portion freezes. Cloudy or Mixed Ice is a combination of Rime and Clear Ice. (Skybrary, 2019)

A way to handle icing, is to prepare for it. Proper flight planning and verifying that you have the proper, working equipment is the best way to manage aircraft in known icing conditions.

References:

Landsberg, Bruce. (2008) AOPA Air Safety Foundation. Safety Advisor: Aircraft Icing [PDF file]. Retrieved from https://www.aopa.org/-/media/Files/AOPA/Home/Pilot-Resources/ASI/Safety-Advisors/sa11.pdf   

Skybrary. (2019, March 31). In-Flight Icing. Retrieved from https://www.skybrary.aero/index.php/In-Flight_Icing