Definition
A knot that forms a fixed, non-slipping loop at the end of a rope. The loop holds its size under load and does not tighten or loosen when tension is applied, yet the knot can be untied easily after the load is removed.
Plain English
A way of tying a rope so it forms a loop that stays the same size when you pull on it, and is still easy to untie afterward.
Context Anchor
Seen when rope is used around aircraft, equipment, or ramp work and a fixed loop is needed for securing or handling something safely.
Derivation
The name comes from old sailing usage, where a line called a 'bowline' was tied to the front (bow) of a square sail to hold its edge forward into the wind. The knot used at the end of that line took the same name.
Why Pilots Care
Provides a secure attachment that will not jam or damage aircraft tie-down rings while protecting the airplane from wind movement.
Intuition Check
Do not think of a bowline knot as a tightening noose. Its main purpose is to make a loop that holds its size under pull.
Example Sentence 1
After parking on the ramp overnight, the pilot secured each wing with a bowline knot tied through the tie-down ring.
Example Sentence 2
After the off-field landing, they used a bowline knot to secure the control lock in place with available rope.