AC 00-6A (Aviation Weather) Chapter 11 states:
Do's and Don'ts of Thunderstorm Flying
- To avoid the most critical icing, establish a penetration altitude below the freezing level or above the level of -15 C.
I'm trying to understand how flying above an altitude where -15 degrees Celsius occurs would help me avoid icing. I'm also trying to understand how flying below the freezing level would help me avoid icing. What is the explanation?