Reading the Signs

All fields of human endeavour have their own languages and conventions. Quilters use words such as “basting” and “applique” and “bearding”. Bird watchers talk about “cripplers” and “LBJ” and “hammer”. Sometimes the language is non-verbal. Hand signals are common in many sports, including baseball and scuba diving. Hand gestures are regularly seen on freeways as drivers indicate their feelings about other drivers. These communication systems are a type of code.

In aviation, we are accustomed to our terminology, and our own radio communication language, but there’s another more subtle non-verbal physical coded communication technique that we use without noticing it: airfield markings. In Basic Aeronautical Knowledge studies we learn the basics of this particular code, and we generally remember the most common markings and eventually “read” them without thinking, such as the number on the runway.

A red and white cone tells us something. A windsock tells us many things. But what does a black cone mean? What does a marking that looks like two joined