Definition
A length of soft iron or steel safety wire that is doubled, inserted through holes in two or more fasteners, and then twisted along its length to lock the fasteners against loosening from vibration. The twisted strand is then secured with a pigtail end at the final fastener.
Plain English
A short piece of wire that has been doubled and twisted into a tight spiral, used to tie fasteners together so they cannot vibrate loose.
Context Anchor
Seen in aircraft composite, fiberglass, and structural repair instructions.
Derivation
Twist comes from Old English meaning to wind or wrap strands together. Rope is used loosely here because the doubled, twisted wire resembles a tiny rope. The name describes the finished appearance of the safety wire after it has been twisted.
Why Pilots Care
A correctly made twist rope keeps critical fasteners from backing out due to engine and airframe vibration. A poorly twisted or under-tensioned wire can fail in service, allowing a fastener to loosen and potentially cause a component failure.
Intuition Check
Twist rope does not mean any ordinary rope from the shop. In this maintenance context, it means a purpose-made bundle of reinforcing fibers used as part of an aircraft repair.
Example Sentence 1
After torquing the oil filter, the technician installed a twist rope through the safety wire holes to prevent the filter from backing off.
Example Sentence 2
After the fabric repair, twist rope served as a temporary hold-down until the dope fully cured.