Definition
A knot in a piece of aircraft-grade wood that has been sawn lengthwise through the limb, appearing as an elongated oval or spike-shaped figure running along the grain of the board. Spike knots are evaluated as a defect when grading wood for aircraft structural use because they affect the strength of the piece along its length.
Plain English
A knot that shows up as a long, narrow streak in a board because the saw cut through the branch lengthwise instead of straight across it.
Context Anchor
Seen in aircraft ground-handling or maintenance rope work, especially when tightening ropes used to secure or move equipment.
Derivation
Called a 'spike' knot because the lengthwise cut through the branch leaves a long, pointed, spike-like figure in the wood, rather than the round dot left by a cross-cut knot.
Why Pilots Care
Spike knots weaken wooden structures more than round knots and can lead to rejection of parts during maintenance.
Analogy
It is like sliding a screwdriver through a loop in a rope so you can use the screwdriver as a handle while you pull.
Intuition Check
Do not read “spike” here as a sudden increase, like an electrical spike. In this term, a spike is a short pin or rod used as a pulling handle.
Example Sentence 1
The mechanic rejected the spruce board for use as a wing spar after finding a spike knot running along several inches of the grain.
Example Sentence 2
Technicians measure spike knots carefully because they reduce the load-carrying strength of wooden aircraft components.