Definition
Wear or damage to a surface caused by repeated rubbing or friction against another object. In aircraft maintenance, chafing typically occurs where wires, hoses, control cables, or tubing contact structure or other components and gradually wear through their protective covering.
Plain English
To rub against something repeatedly until it wears down or gets damaged. On an aircraft, it means parts that touch each other and slowly wear away from the constant rubbing.
Context Anchor
Seen during preflight and maintenance inspections of wiring, hoses, control cables, fuel lines, and places where aircraft parts can rub against each other.
Derivation
From the Old French chaufer, meaning 'to warm,' because rubbing two things together produces heat. Over time the word came to mean the wearing or fraying caused by that rubbing.
Why Pilots Care
Unchecked chafing can cause electrical shorts, fuel leaks, or control cable failure.
Intuition Check
Chafe does not mean harmless light rubbing. In aircraft, it means rubbing that is causing, or can soon cause, real wear or damage.
Example Sentence 1
During the inspection, the mechanic found a wire bundle starting to chafe against a bracket and added protective tape to prevent further wear.
Example Sentence 2
During the inspection we found the fuel line starting to chafe where it passed through the firewall.